Add circleci and codecov (#13)

* Add circleci and codecov

* Update version

* Fix format test

* Fix CI

* Add tarpaulin

* Format code

* Fix tarpaulin

* lexers tests

* Remove non-lexer token type, add more tests

* More tests

* More tests

* Refactor, some test, split code, add more traits

* Add codecov config

* Fix code style

* Test text character

* Menu bar tests

* Caret tests

* Refactor caret, more caret tests

.circleci/config.yml

@@ -0,0 +1,54 @@
+version: 2.1
+
+jobs:
+  build:
+    working_directory: ~/rider
+    docker:
+      - image: abronan/rust-circleci:latest
+
+    environment:
+      CODECOV_TOKEN: "e58da505-19f2-481c-8068-e845cb36fbe4"
+      TZ: "/usr/share/zoneinfo/Europe/Paris"
+
+    steps:
+      - checkout
+      - restore_cache:
+          key: project-cache
+      - run:
+          name: Install dependencies
+          command: |
+            apt-get update
+            apt-get install -y -qq xvfb mesa-utils mesa-vdpau-drivers
+            apt-get install -y libssl-dev pkg-config cmake zlib1g-dev
+            apt-get install -q -y libsdl2-dev libsdl2-2.0-0 libsdl2-gfx-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-net-dev libsdl2-ttf-dev
+      - run:
+          name: Check formatting
+          command: |
+            rustfmt --version
+            cargo fmt -- --error-on-unformatted --unstable-features --check
+      - run:
+          name: Nightly Build
+          command: |
+            rustup run nightly rustc --version --verbose
+            rustup run nightly cargo --version --verbose
+            rustup run nightly cargo build
+      - run:
+          name: Test and code coverage
+          command: |
+            RUSTFLAGS="--cfg procmacro2_semver_exempt" cargo install cargo-tarpaulin
+            Xvfb :5 -screen 0 800x600x24 +extension GLX +render -noreset &
+            export DISPLAY=:5
+            export XDG_RUNTIME_DIR=$(pwd)
+            rustup run nightly cargo tarpaulin --ciserver circle-ci --out Xml
+      - run:
+          name: Upload Coverage
+          command: |
+            wget -O - -q "https://codecov.io/bash" > .codecov
+            chmod +x .codecov
+            ./.codecov -t $CODECOV_TOKEN
+            echo "Uploaded code coverage"
+      - save_cache:
+          key: project-cache
+          paths:
+            - "~/.cargo"
+            - "./target"

.codecov.yml

@@ -0,0 +1,18 @@
+codecov:
+  notify:
+    require_ci_to_pass: yes
+
+coverage:
+  precision: 2
+  round: down
+  range: "70...100"
+
+  status:
+    project: yes
+    patch: yes
+    changes: yes
+
+comment:
+  layout: "header, diff"
+  behavior: default
+  require_changes: no

.gitignore

@@ -3,3 +3,5 @@
 .idea
 log
 .rider
+.codecov
+cobertura.xml

Cargo.lock

@@ -416,6 +416,7 @@ version = "0.1.0"
 dependencies = [
  "dirs 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "plex 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -14,6 +14,7 @@ serde_derive = "*"
 log = "*"
 env_logger = "*"
 simplelog = "*"
+lazy_static = "*"
 
 [dependencies.sdl2]
 version = "0.31.0"

README.md

@@ -18,8 +18,9 @@ Text editor in rust
 * [ ] Lock scroll when no available content
 * [ ] Config edit menu
 * [ ] Project tree
-* [ ] Cover `rider` with tests
+* [ ] Cover `rider` with tests at least 50%
 * [x] Handle resize window
+* [ ] Selection
 
 ### v1.1
 
@@ -29,6 +30,8 @@ Text editor in rust
 * [ ] Git support
 * [ ] Context menu
 * [ ] Keep indent
+* [ ] Multi-selection
+* [ ] Cover `rider` with tests at least 75%
 
 ### v1.2
 * [ ] Multi-caret

guitest/main.rs

@@ -0,0 +1,130 @@
+#[cfg(test)]
+mod file_editor {
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn add_text() {
+        use crate::tests::support;
+        let config = support::build_config();
+        let canvas = support::build_canvas();
+        let font_context = sdl2::ttf::init().unwrap();
+        let texture_creator = canvas.texture_creator();
+        let mut renderer = Renderer::new(Arc::clone(&config), &font_context, &texture_creator);
+
+        let mut editor = FileEditor::new(Arc::clone(&config));
+        let mut file = EditorFile::new("./foo.txt".to_string(), "foo".to_string(), config.clone());
+        file.prepare_ui(&mut renderer);
+        assert_eq!(editor.open_file(file).is_none(), true);
+        assert_eq!(editor.caret().position().text_position(), 0);
+        assert_eq!(editor.file().is_some(), true);
+        assert_eq!(editor.file().unwrap().sections().len(), 1);
+        assert_eq!(editor.file().unwrap().get_character_at(0).is_some(), true);
+
+        editor.insert_text("z".to_string(), &mut renderer);
+        assert_eq!(editor.caret().position().text_position(), 1);
+        assert_eq!(editor.file().is_some(), true);
+        assert_eq!(editor.file().unwrap().buffer(), "zfoo".to_string());
+    }
+}
+
+#[cfg(test)]
+mod text_character {
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_return_valid_source() {
+        let config = support::build_config();
+        let canvas = support::build_canvas();
+        let font_context = sdl2::ttf::init().unwrap();
+        let texture_creator = canvas.texture_creator();
+        let mut renderer = Renderer::new(Arc::clone(&config), &font_context, &texture_creator);
+
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(1, 12, 123), Arc::clone(&config));
+        widget.prepare_ui(&mut renderer);
+        assert_eq!(widget.source(), &Rect::new(0, 0, 0, 0));
+    }
+
+    #[test]
+    fn must_return_valid_dest() {
+        let config = support::build_config();
+        let canvas = support::build_canvas();
+        let font_context = sdl2::ttf::init().unwrap();
+        let texture_creator = canvas.texture_creator();
+        let mut renderer = Renderer::new(Arc::clone(&config), &font_context, &texture_creator);
+
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(1, 12, 123), Arc::clone(&config));
+        widget.prepare_ui(&mut renderer);
+        assert_eq!(widget.dest(), &Rect::new(0, 0, 0, 0));
+    }
+
+    #[test]
+    fn must_return_valid_color() {
+        let config = support::build_config();
+        let canvas = support::build_canvas();
+        let font_context = sdl2::ttf::init().unwrap();
+        let texture_creator = canvas.texture_creator();
+        let mut renderer = Renderer::new(Arc::clone(&config), &font_context, &texture_creator);
+
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(1, 12, 123), Arc::clone(&config));
+        widget.prepare_ui(&mut renderer);
+        assert_eq!(widget.color(), &Color::RGB(1, 12, 123));
+    }
+
+    #[test]
+    fn must_update_position_of_new_line() {
+        let config = support::build_config();
+
+        let sdl_context = sdl2::init().unwrap();
+        let video_subsystem = sdl_context.video().unwrap();
+
+
+        let window = video_subsystem
+            .window("Test", 1, 1)
+            .borderless()
+            .opengl()
+            .build()
+            .unwrap();
+
+        let canvas = window.into_canvas().accelerated().build().unwrap();
+
+        let font_context = sdl2::ttf::init().unwrap();
+        let texture_creator = canvas.texture_creator();
+        let mut renderer = Renderer::new(Arc::clone(&config), &font_context, &texture_creator);
+
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.prepare_ui(&mut renderer);
+        let mut current = Rect::new(0, 0, 0, 0);
+        widget.update_position(&mut current);
+        assert_eq!(current, Rect::new(0, 0, 0, 0));
+        assert_eq!(widget.dest(), &Rect::new(0, 0, 0, 0));
+    }
+}
+
+
+
+#[cfg(test)]
+fn main() {
+        let config = support::build_config();
+
+        let sdl_context = sdl2::init().unwrap();
+        let video_subsystem = sdl_context.video().unwrap();
+
+
+        let window = video_subsystem
+            .window("Test", 1, 1)
+            .borderless()
+            .opengl()
+            .build()
+            .unwrap();
+
+        let canvas = window.into_canvas().accelerated().build().unwrap();
+
+}

src/app/app_state.rs

@@ -1,10 +1,9 @@
 use crate::app::caret_manager;
 use crate::app::file_content_manager;
 use crate::app::{UpdateResult, WindowCanvas as WC};
-use crate::config::Config;
+use crate::config::*;
 use crate::renderer::Renderer;
-use crate::ui::caret::Caret;
-use crate::ui::caret::{CaretPosition, MoveDirection};
+use crate::ui::caret::*;
 use crate::ui::file::editor_file::EditorFile;
 use crate::ui::file::*;
 use crate::ui::menu_bar::MenuBar;
@@ -48,10 +47,6 @@ impl AppState {
         };
     }
 
-    pub fn config(&self) -> &Arc<RwLock<Config>> {
-        &self.config
-    }
-
     pub fn file_editor(&self) -> &FileEditor {
         &self.file_editor
     }
@@ -62,9 +57,9 @@ impl AppState {
 }
 
 impl Render for AppState {
-    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, _parent: Parent) -> UpdateResult {
+    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, _parent: Parent) {
         self.file_editor.render(canvas, renderer, None);
-        self.menu_bar.render(canvas, renderer, None)
+        self.menu_bar.render(canvas, renderer, None);
     }
 
     fn prepare_ui(&mut self, renderer: &mut Renderer) {
@@ -108,3 +103,9 @@ impl AppState {
         true
     }
 }
+
+impl ConfigHolder for AppState {
+    fn config(&self) -> &ConfigAccess {
+        &self.config
+    }
+}

src/app/application.rs

@@ -1,5 +1,5 @@
 pub use crate::app::app_state::AppState;
-pub use crate::config::Config;
+pub use crate::config::{Config, ConfigAccess, ConfigHolder};
 pub use crate::renderer::Renderer;
 use crate::themes::*;
 use crate::ui::caret::{CaretPosition, MoveDirection};
@@ -251,8 +251,10 @@ impl Application {
         }
         UpdateResult::NoOp
     }
+}
 
-    pub fn config(&self) -> &Arc<RwLock<Config>> {
+impl ConfigHolder for Application {
+    fn config(&self) -> &ConfigAccess {
         &self.config
     }
 }

src/config/config.rs

@@ -0,0 +1,114 @@
+use crate::config::creator;
+use crate::config::EditorConfig;
+use crate::lexer::Language;
+use crate::themes::Theme;
+use dirs;
+use std::collections::HashMap;
+use std::fs;
+
+pub type LanguageMapping = HashMap<String, Language>;
+
+#[derive(Debug, Clone)]
+pub struct Config {
+    width: u32,
+    height: u32,
+    scroll_speed: i32,
+    menu_height: u16,
+    editor_config: EditorConfig,
+    theme: Theme,
+    extensions_mapping: LanguageMapping,
+}
+
+impl Config {
+    pub fn new() -> Self {
+        creator::create();
+        let editor_config = EditorConfig::new();
+        let mut extensions_mapping = HashMap::new();
+        extensions_mapping.insert(".".to_string(), Language::PlainText);
+        extensions_mapping.insert("txt".to_string(), Language::PlainText);
+        extensions_mapping.insert("rs".to_string(), Language::Rust);
+
+        Self {
+            width: 1024,
+            height: 860,
+            scroll_speed: 10,
+            menu_height: 60,
+            theme: Theme::load(editor_config.current_theme().clone()),
+            editor_config,
+            extensions_mapping,
+        }
+    }
+
+    pub fn scroll_speed(&self) -> i32 {
+        self.scroll_speed
+    }
+
+    pub fn width(&self) -> u32 {
+        self.width
+    }
+
+    pub fn set_width(&mut self, w: u32) {
+        self.width = w;
+    }
+
+    pub fn height(&self) -> u32 {
+        self.height
+    }
+
+    pub fn set_height(&mut self, h: u32) {
+        self.height = h;
+    }
+
+    pub fn editor_config(&self) -> &EditorConfig {
+        &self.editor_config
+    }
+
+    pub fn theme(&self) -> &Theme {
+        &self.theme
+    }
+
+    pub fn menu_height(&self) -> u16 {
+        self.menu_height
+    }
+
+    pub fn editor_top_margin(&self) -> i32 {
+        (self.menu_height() as i32) + (self.editor_config().margin_top() as i32)
+    }
+
+    pub fn editor_left_margin(&self) -> i32 {
+        self.editor_config().margin_left() as i32
+    }
+
+    pub fn extensions_mapping(&self) -> &LanguageMapping {
+        &self.extensions_mapping
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::config::*;
+    use crate::lexer::*;
+
+    #[test]
+    fn must_return_language_mapping() {
+        let config = Config::new();
+
+        let mapping = config.extensions_mapping();
+        {
+            let mut keys: Vec<String> = mapping.keys().map(|s| s.to_string()).collect();
+            let mut expected: Vec<String> =
+                vec![".".to_string(), "txt".to_string(), "rs".to_string()];
+            keys.sort();
+            expected.sort();
+            assert_eq!(keys, expected);
+        }
+        {
+            let mut keys: Vec<Language> = mapping.values().map(|s| s.clone()).collect();
+            let mut expected: Vec<Language> =
+                vec![Language::PlainText, Language::PlainText, Language::Rust];
+            keys.sort();
+            expected.sort();
+            assert_eq!(keys, expected);
+        }
+    }
+}

src/config/creator.rs

@@ -6,23 +6,28 @@ use std::path;
 
 pub fn create() {
     if !themes_dir().exists() {
-        fs::create_dir_all(&themes_dir())
-            .unwrap_or_else(|_| panic!("Cannot create themes config directory"));
+        let r = fs::create_dir_all(&themes_dir());
+        #[cfg_attr(tarpaulin, skip)]
+        r.unwrap_or_else(|_| panic!("Cannot create themes config directory"));
     }
 
     if !fonts_dir().exists() {
-        fs::create_dir_all(&fonts_dir())
-            .unwrap_or_else(|_| panic!("Cannot create fonts config directory"));
+        let r = fs::create_dir_all(&fonts_dir());
+        #[cfg_attr(tarpaulin, skip)]
+        r.unwrap_or_else(|_| panic!("Cannot create fonts config directory"));
         write_default_fonts();
     }
 
     if !log_dir().exists() {
-        fs::create_dir_all(&log_dir()).unwrap_or_else(|_| panic!("Cannot create log directory"));
+        let r = fs::create_dir_all(&log_dir());
+        #[cfg_attr(tarpaulin, skip)]
+        r.unwrap_or_else(|_| panic!("Cannot create log directory"));
     }
 
     if !project_dir().exists() {
-        fs::create_dir_all(&project_dir())
-            .unwrap_or_else(|_| panic!("Cannot create project directory"));
+        let r = fs::create_dir_all(&project_dir());
+        #[cfg_attr(tarpaulin, skip)]
+        r.unwrap_or_else(|_| panic!("Cannot create project directory"));
     }
 }
 
@@ -31,14 +36,16 @@ fn write_default_fonts() {
         let mut default_font_path = fonts_dir();
         default_font_path.push("DejaVuSansMono.ttf");
         let contents = include_bytes!("../../assets/fonts/DejaVuSansMono.ttf");
-        fs::write(default_font_path, contents.to_vec())
-            .unwrap_or_else(|_| panic!("Cannot write default font file!"));
+        let r = fs::write(default_font_path, contents.to_vec());
+        #[cfg_attr(tarpaulin, skip)]
+        r.unwrap_or_else(|_| panic!("Cannot write default font file!"));
     }
     {
         let mut default_font_path = fonts_dir();
         default_font_path.push("ElaineSans-Medium.ttf");
         let contents = include_bytes!("../../assets/fonts/ElaineSans-Medium.ttf");
-        fs::write(default_font_path, contents.to_vec())
-            .unwrap_or_else(|_| panic!("Cannot write default font file!"));
+        let r = fs::write(default_font_path, contents.to_vec());
+        #[cfg_attr(tarpaulin, skip)]
+        r.unwrap_or_else(|_| panic!("Cannot write default font file!"));
     }
 }

src/config/editor_config.rs

@@ -0,0 +1,44 @@
+use crate::config::directories;
+
+#[derive(Debug, Clone)]
+pub struct EditorConfig {
+    character_size: u16,
+    font_path: String,
+    current_theme: String,
+    margin_left: u16,
+    margin_top: u16,
+}
+
+impl EditorConfig {
+    pub fn new() -> Self {
+        let mut default_font_path = directories::fonts_dir();
+        default_font_path.push("DejaVuSansMono.ttf");
+        Self {
+            character_size: 14,
+            font_path: default_font_path.to_str().unwrap().to_string(),
+            current_theme: "railscasts".to_string(),
+            margin_left: 10,
+            margin_top: 10,
+        }
+    }
+
+    pub fn character_size(&self) -> u16 {
+        self.character_size
+    }
+
+    pub fn font_path(&self) -> &String {
+        &self.font_path
+    }
+
+    pub fn current_theme(&self) -> &String {
+        &self.current_theme
+    }
+
+    pub fn margin_left(&self) -> u16 {
+        self.margin_left
+    }
+
+    pub fn margin_top(&self) -> u16 {
+        self.margin_top
+    }
+}

src/config/mod.rs

@@ -1,129 +1,16 @@
-use crate::lexer::Language;
-use crate::themes::Theme;
-use dirs;
-use std::collections::HashMap;
-use std::fs;
+use std::sync::{Arc, RwLock};
 
-mod creator;
+pub mod config;
+pub(crate) mod creator;
 pub mod directories;
+pub mod editor_config;
 
-type LanguageMapping = HashMap<String, Language>;
+pub use crate::config::config::*;
+pub use crate::config::directories::*;
+pub use crate::config::editor_config::*;
 
-#[derive(Debug, Clone)]
-pub struct EditorConfig {
-    character_size: u16,
-    font_path: String,
-    current_theme: String,
-    margin_left: u16,
-    margin_top: u16,
-}
-
-impl EditorConfig {
-    pub fn new() -> Self {
-        let mut default_font_path = directories::fonts_dir();
-        default_font_path.push("DejaVuSansMono.ttf");
-        Self {
-            character_size: 14,
-            font_path: default_font_path.to_str().unwrap().to_string(),
-            current_theme: "railscasts".to_string(),
-            margin_left: 10,
-            margin_top: 10,
-        }
-    }
-
-    pub fn character_size(&self) -> u16 {
-        self.character_size
-    }
-
-    pub fn font_path(&self) -> &String {
-        &self.font_path
-    }
-
-    pub fn current_theme(&self) -> &String {
-        &self.current_theme
-    }
-
-    pub fn margin_left(&self) -> u16 {
-        self.margin_left
-    }
-
-    pub fn margin_top(&self) -> u16 {
-        self.margin_top
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct Config {
-    width: u32,
-    height: u32,
-    scroll_speed: i32,
-    menu_height: u16,
-    editor_config: EditorConfig,
-    theme: Theme,
-    extensions_mapping: LanguageMapping,
-}
-
-impl Config {
-    pub fn new() -> Self {
-        creator::create();
-        let editor_config = EditorConfig::new();
-        let mut extensions_mapping = HashMap::new();
-        extensions_mapping.insert(".".to_string(), Language::PlainText);
-        extensions_mapping.insert("txt".to_string(), Language::PlainText);
-        extensions_mapping.insert("rs".to_string(), Language::Rust);
-
-        Self {
-            width: 1024,
-            height: 860,
-            scroll_speed: 10,
-            menu_height: 60,
-            theme: Theme::load(editor_config.current_theme().clone()),
-            editor_config,
-            extensions_mapping,
-        }
-    }
-
-    pub fn scroll_speed(&self) -> i32 {
-        self.scroll_speed
-    }
-
-    pub fn width(&self) -> u32 {
-        self.width
-    }
-
-    pub fn set_width(&mut self, w: u32) {
-        self.width = w;
-    }
-
-    pub fn height(&self) -> u32 {
-        self.height
-    }
-
-    pub fn set_height(&mut self, h: u32) {
-        self.height = h;
-    }
-
-    pub fn editor_config(&self) -> &EditorConfig {
-        &self.editor_config
-    }
-
-    pub fn theme(&self) -> &Theme {
-        &self.theme
-    }
-
-    pub fn menu_height(&self) -> u16 {
-        self.menu_height
-    }
-
-    pub fn editor_top_margin(&self) -> i32 {
-        (self.menu_height() as i32) + (self.editor_config().margin_top() as i32)
-    }
-
-    pub fn editor_left_margin(&self) -> i32 {
-        self.editor_config().margin_left() as i32
-    }
-
-    pub fn extensions_mapping(&self) -> &LanguageMapping {
-        &self.extensions_mapping
-    }
+pub type ConfigAccess = Arc<RwLock<Config>>;
+
+pub trait ConfigHolder {
+    fn config(&self) -> &ConfigAccess;
 }

src/lexer/mod.rs

@@ -3,18 +3,17 @@ use std::ops::Deref;
 pub mod plain;
 pub mod rust_lang;
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Ord, Eq)]
 pub enum Language {
     PlainText,
     Rust,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum TokenType {
     Whitespace { token: Token },
     Keyword { token: Token },
     String { token: Token },
-    Number { token: Token },
     Identifier { token: Token },
     Literal { token: Token },
     Comment { token: Token },
@@ -34,9 +33,6 @@ impl TokenType {
             TokenType::String { token } => TokenType::String {
                 token: token.move_to(line, character, start, end),
             },
-            TokenType::Number { token } => TokenType::Number {
-                token: token.move_to(line, character, start, end),
-            },
             TokenType::Identifier { token } => TokenType::Identifier {
                 token: token.move_to(line, character, start, end),
             },
@@ -78,7 +74,6 @@ impl Deref for TokenType {
             TokenType::Whitespace { token } => token,
             TokenType::Keyword { token } => token,
             TokenType::String { token } => token,
-            TokenType::Number { token } => token,
             TokenType::Identifier { token } => token,
             TokenType::Literal { token } => token,
             TokenType::Comment { token } => token,
@@ -88,7 +83,13 @@ impl Deref for TokenType {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Span {
+    pub lo: usize,
+    pub hi: usize,
+}
+
+#[derive(Debug, Clone, PartialEq)]
 pub struct Token {
     line: usize,
     character: usize,
@@ -97,12 +98,6 @@ pub struct Token {
     text: String,
 }
 
-#[derive(Debug, Clone, Copy)]
-pub struct Span {
-    pub lo: usize,
-    pub hi: usize,
-}
-
 impl Token {
     pub fn new(text: String, line: usize, character: usize, start: usize, end: usize) -> Self {
         Self {
@@ -157,3 +152,73 @@ pub fn parse(text: String, language: &Language) -> Vec<TokenType> {
             .collect(),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::lexer::*;
+
+    #[test]
+    fn must_parse_plain() {
+        let buffer = "foo bar";
+        let language = &Language::PlainText;
+        let result = parse(buffer.to_string(), language);
+        assert_eq!(result.len(), 3);
+    }
+
+    #[test]
+    fn must_parse_rust() {
+        let buffer = "foo bar";
+        let language = &Language::Rust;
+        let result = parse(buffer.to_string(), language);
+        assert_eq!(result.len(), 3);
+    }
+
+    #[test]
+    fn must_return_valid_value_for_text() {
+        let token = Token::new("a".to_string(), 1, 2, 3, 4);
+        let result = token.text();
+        let text: String = "a".to_string();
+        let expected = &text;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_return_valid_value_for_line() {
+        let token = Token::new("a".to_string(), 1, 2, 3, 4);
+        let result = token.line();
+        let expected = 1;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_return_valid_value_for_character() {
+        let token = Token::new("a".to_string(), 1, 2, 3, 4);
+        let result = token.character();
+        let expected = 2;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_return_valid_value_for_start() {
+        let token = Token::new("a".to_string(), 1, 2, 3, 4);
+        let result = token.start();
+        let expected = 3;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_return_valid_value_for_end() {
+        let token = Token::new("a".to_string(), 1, 2, 3, 4);
+        let result = token.end();
+        let expected = 4;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_return_valid_value_for_move_to() {
+        let token = Token::new("a".to_string(), 1, 2, 3, 4);
+        let result = token.move_to(5, 6, 7, 8);
+        let expected = Token::new("a".to_string(), 5, 6, 7, 8);
+        assert_eq!(result, expected);
+    }
+}

src/lexer/plain.rs

@@ -77,3 +77,140 @@ pub mod lexer {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::lexer::plain::*;
+    use crate::lexer::*;
+
+    #[test]
+    fn must_parse_simple_text() {
+        let code = "foo";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![TokenType::Identifier {
+            token: Token::new("foo".to_string(), 0, 0, 0, 3),
+        }];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_long_text() {
+        let code = "foobarhelloworldexamplecomtesttest";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![TokenType::Identifier {
+            token: Token::new(
+                "foobarhelloworldexamplecomtesttest".to_string(),
+                0,
+                0,
+                0,
+                34,
+            ),
+        }];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_space() {
+        let code = "foo bar";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 0, 4, 4, 7),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_one_multi_character_space() {
+        let code = "foo      bar";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 4, 4, 5),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 5, 5, 6),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 6, 6, 7),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 8, 8, 9),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 0, 9, 9, 12),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_multiple_spaces() {
+        let code = "foo bar hello world";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 0, 4, 4, 7),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Identifier {
+                token: Token::new("hello".to_string(), 0, 8, 8, 13),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 13, 13, 14),
+            },
+            TokenType::Identifier {
+                token: Token::new("world".to_string(), 0, 14, 14, 19),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_new_line() {
+        let code = "foo\nbar";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new("\n".to_string(), 1, 0, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 1, 1, 4, 7),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+}

src/lexer/rust_lang.rs

@@ -11,23 +11,23 @@ pub mod lexer {
             token: Token::new(text.to_string(), 0, 0, 0, 0)
         }, text),
 
-        r"(\d+|\d+\.\d+|'[\S]')" => (TokenType::Literal {
+        r"([0-9]+|[0-9]+\.[0-9]+|'[^']')" => (TokenType::Literal {
             token: Token::new(text.to_string(), 0, 0, 0, 0)
         }, text),
 
-        r"[+-/*%=<>]" => (TokenType::Operator {
+        r"(->|[+-/*%=<>#])" => (TokenType::Operator {
             token: Token::new(text.to_string(), 0, 0, 0, 0)
         }, text),
 
-        r"(:|::|\{|\}|\[|\]|,)" => (TokenType::Separator {
+        r"(:|::|\{|\}|\[|\]|;|,|\)|\()" => (TokenType::Separator {
             token: Token::new(text.to_string(), 0, 0, 0, 0)
         }, text),
 
-        r"(let|fn|type|struct|pub|impl|for|self|Self|mod|use|enum)" => (TokenType::Keyword {
+        r"(let|fn|type|struct|pub|impl|for|self|Self|mod|use|enum|(iu)(8|16|32)|usize|bool)" => (TokenType::Keyword {
             token: Token::new(text.to_string(), 0, 0, 0, 0)
         }, text),
 
-        r"[^ \t\r\n:+-/*,]+" => (TokenType::Identifier {
+        r"[^0-9 \t\r\n:+-/*,';<>=%()\[\]{}][^ \t\r\n:+-/*,';<>=%()\[\]{}]*" => (TokenType::Identifier {
             token: Token::new(text.to_string(), 0, 0, 0, 0)
         }, text),
     }
@@ -94,3 +94,383 @@ pub mod lexer {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::lexer::rust_lang::*;
+    use crate::lexer::*;
+
+    #[test]
+    fn must_parse_simple_text() {
+        let code = "foo";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![TokenType::Identifier {
+            token: Token::new("foo".to_string(), 0, 0, 0, 3),
+        }];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_long_text() {
+        let code = "foobarhelloworldexamplecomtesttest";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![TokenType::Identifier {
+            token: Token::new(
+                "foobarhelloworldexamplecomtesttest".to_string(),
+                0,
+                0,
+                0,
+                34,
+            ),
+        }];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_space() {
+        let code = "foo bar";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 0, 4, 4, 7),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_one_multi_character_space() {
+        let code = "foo      bar";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new("      ".to_string(), 0, 3, 3, 9),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 0, 9, 9, 12),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_multiple_spaces() {
+        let code = "foo bar hello world";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 0, 4, 4, 7),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Identifier {
+                token: Token::new("hello".to_string(), 0, 8, 8, 13),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 13, 13, 14),
+            },
+            TokenType::Identifier {
+                token: Token::new("world".to_string(), 0, 14, 14, 19),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_text_with_new_line() {
+        let code = "foo\nbar";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new("\n".to_string(), 1, 0, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("bar".to_string(), 1, 1, 4, 7),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_keyword_let_and_char_literal() {
+        let code = "let a = 'b';";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Keyword {
+                token: Token::new("let".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("a".to_string(), 0, 4, 4, 5),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 5, 5, 6),
+            },
+            TokenType::Operator {
+                token: Token::new("=".to_string(), 0, 6, 6, 7),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Literal {
+                token: Token::new("'b'".to_string(), 0, 8, 8, 11),
+            },
+            TokenType::Separator {
+                token: Token::new(";".to_string(), 0, 11, 11, 12),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_keyword_let_and_number_literal() {
+        let code = "let a = 684;";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Keyword {
+                token: Token::new("let".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("a".to_string(), 0, 4, 4, 5),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 5, 5, 6),
+            },
+            TokenType::Operator {
+                token: Token::new("=".to_string(), 0, 6, 6, 7),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Literal {
+                token: Token::new("684".to_string(), 0, 8, 8, 11),
+            },
+            TokenType::Separator {
+                token: Token::new(";".to_string(), 0, 11, 11, 12),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_calculation() {
+        let code = "let a = b + 684;";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Keyword {
+                token: Token::new("let".to_string(), 0, 0, 0, 3),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 3, 3, 4),
+            },
+            TokenType::Identifier {
+                token: Token::new("a".to_string(), 0, 4, 4, 5),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 5, 5, 6),
+            },
+            TokenType::Operator {
+                token: Token::new("=".to_string(), 0, 6, 6, 7),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Identifier {
+                token: Token::new("b".to_string(), 0, 8, 8, 9),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 9, 9, 10),
+            },
+            TokenType::Operator {
+                token: Token::new("+".to_string(), 0, 10, 10, 11),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 11, 11, 12),
+            },
+            TokenType::Literal {
+                token: Token::new("684".to_string(), 0, 12, 12, 15),
+            },
+            TokenType::Separator {
+                token: Token::new(";".to_string(), 0, 15, 15, 16),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_function() {
+        let code = r"fn foo(a: i32, b: i32) -> int {
+            a % b
+        }";
+        let lexer = lexer::Lexer::new(code);
+        let result: Vec<TokenType> = lexer.map(|pair| pair.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Keyword {
+                token: Token::new("fn".to_string(), 0, 0, 0, 2),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 2, 2, 3),
+            },
+            TokenType::Identifier {
+                token: Token::new("foo".to_string(), 0, 3, 3, 6),
+            },
+            TokenType::Separator {
+                token: Token::new("(".to_string(), 0, 6, 6, 7),
+            },
+            TokenType::Identifier {
+                token: Token::new("a".to_string(), 0, 7, 7, 8),
+            },
+            TokenType::Separator {
+                token: Token::new(":".to_string(), 0, 8, 8, 9),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 9, 9, 10),
+            },
+            TokenType::Identifier {
+                token: Token::new("i32".to_string(), 0, 10, 10, 13),
+            },
+            TokenType::Operator {
+                token: Token::new(",".to_string(), 0, 13, 13, 14),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 14, 14, 15),
+            },
+            TokenType::Identifier {
+                token: Token::new("b".to_string(), 0, 15, 15, 16),
+            },
+            TokenType::Separator {
+                token: Token::new(":".to_string(), 0, 16, 16, 17),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 17, 17, 18),
+            },
+            TokenType::Identifier {
+                token: Token::new("i32".to_string(), 0, 18, 18, 21),
+            },
+            TokenType::Separator {
+                token: Token::new(")".to_string(), 0, 21, 21, 22),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 22, 22, 23),
+            },
+            TokenType::Operator {
+                token: Token::new("->".to_string(), 0, 23, 23, 25),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 25, 25, 26),
+            },
+            TokenType::Identifier {
+                token: Token::new("int".to_string(), 0, 26, 26, 29),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 29, 29, 30),
+            },
+            TokenType::Separator {
+                token: Token::new("{".to_string(), 0, 30, 30, 31),
+            },
+            TokenType::Whitespace {
+                token: Token::new("\n".to_string(), 1, 0, 31, 32),
+            },
+            TokenType::Whitespace {
+                token: Token::new("            ".to_string(), 1, 1, 32, 44),
+            },
+            TokenType::Identifier {
+                token: Token::new("a".to_string(), 1, 13, 44, 45),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 1, 14, 45, 46),
+            },
+            TokenType::Operator {
+                token: Token::new("%".to_string(), 1, 15, 46, 47),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 1, 16, 47, 48),
+            },
+            TokenType::Identifier {
+                token: Token::new("b".to_string(), 1, 17, 48, 49),
+            },
+            TokenType::Whitespace {
+                token: Token::new("\n".to_string(), 2, 0, 49, 50),
+            },
+            TokenType::Whitespace {
+                token: Token::new("        ".to_string(), 2, 1, 50, 58),
+            },
+            TokenType::Separator {
+                token: Token::new("}".to_string(), 2, 9, 58, 59),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_parse_derive() {
+        let buffer = "#[derive(Debug, Clone)]";
+        let result: Vec<TokenType> = lexer::Lexer::new(buffer).map(|p| p.0).collect();
+        let expected: Vec<TokenType> = vec![
+            TokenType::Operator {
+                token: Token::new("#".to_string(), 0, 0, 0, 1),
+            },
+            TokenType::Separator {
+                token: Token::new("[".to_string(), 0, 1, 1, 2),
+            },
+            TokenType::Identifier {
+                token: Token::new("derive".to_string(), 0, 2, 2, 8),
+            },
+            TokenType::Separator {
+                token: Token::new("(".to_string(), 0, 8, 8, 9),
+            },
+            TokenType::Identifier {
+                token: Token::new("Debug".to_string(), 0, 9, 9, 14),
+            },
+            TokenType::Operator {
+                token: Token::new(",".to_string(), 0, 14, 14, 15),
+            },
+            TokenType::Whitespace {
+                token: Token::new(" ".to_string(), 0, 15, 15, 16),
+            },
+            TokenType::Identifier {
+                token: Token::new("Clone".to_string(), 0, 16, 16, 21),
+            },
+            TokenType::Separator {
+                token: Token::new(")".to_string(), 0, 21, 21, 22),
+            },
+            TokenType::Separator {
+                token: Token::new("]".to_string(), 0, 22, 22, 23),
+            },
+        ];
+        assert_eq!(result, expected);
+    }
+}

src/main.rs

@@ -13,6 +13,8 @@ extern crate serde_json;
 #[macro_use]
 extern crate log;
 extern crate simplelog;
+#[macro_use]
+extern crate lazy_static;
 
 use crate::app::Application;
 use crate::config::directories::log_dir;
@@ -25,22 +27,27 @@ pub mod app;
 pub mod config;
 pub mod lexer;
 pub mod renderer;
+#[cfg(test)]
+pub mod tests;
 pub mod themes;
 pub mod ui;
 
 fn init_logger() {
+    use simplelog::SharedLogger;
+
     let mut log_file_path = log_dir();
     log_file_path.push("rider.log");
 
-    CombinedLogger::init(vec![
-        TermLogger::new(LevelFilter::Warn, Config::default()).unwrap(),
-        WriteLogger::new(
-            LevelFilter::Info,
-            Config::default(),
-            File::create(log_file_path).unwrap(),
-        ),
-    ])
-    .unwrap();
+    let mut outputs: Vec<Box<SharedLogger>> = vec![WriteLogger::new(
+        LevelFilter::Info,
+        Config::default(),
+        File::create(log_file_path).unwrap(),
+    )];
+    if let Some(term) = TermLogger::new(LevelFilter::Warn, Config::default()) {
+        outputs.push(term);
+    }
+
+    CombinedLogger::init(outputs).unwrap();
 }
 
 fn main() {

src/renderer/managers.rs

@@ -2,6 +2,7 @@ use sdl2::image::LoadTexture;
 use sdl2::pixels::Color;
 use sdl2::render::{Texture, TextureCreator};
 use sdl2::ttf::{Font, Sdl2TtfContext};
+use sdl2::video::WindowContext as WinCtxt;
 use std::borrow::Borrow;
 use std::collections::HashMap;
 #[allow(unused_imports)]
@@ -9,6 +10,10 @@ use std::env;
 use std::hash::Hash;
 use std::rc::Rc;
 
+//noinspection RsWrongLifetimeParametersNumber
+pub type RcTex<'l> = Rc<Texture<'l>>;
+pub type RcFont<'l> = Rc<Font<'l, 'static>>;
+
 pub trait ResourceLoader<'l, R> {
     type Args: ?Sized;
 
@@ -70,6 +75,12 @@ impl<'a> From<&'a FontDetails> for FontDetails {
 pub type TextureManager<'l, T> = ResourceManager<'l, String, Texture<'l>, TextureCreator<T>>;
 pub type FontManager<'l> = ResourceManager<'l, FontDetails, Font<'l, 'static>, Sdl2TtfContext>;
 
+pub trait ManagersHolder<'l> {
+    fn font_manager(&mut self) -> &mut FontManager<'l>;
+
+    fn texture_manager(&mut self) -> &mut TextureManager<'l, WinCtxt>;
+}
+
 #[derive(Clone)]
 pub struct ResourceManager<'l, K, R, L>
 where
@@ -132,9 +143,18 @@ impl<'l> ResourceLoader<'l, Font<'l, 'static>> for Sdl2TtfContext {
     }
 }
 
-impl<'l, T> TextureManager<'l, T> {
+pub trait TextTextureManager<'l> {
     //noinspection RsWrongLifetimeParametersNumber
-    pub fn load_text(
+    fn load_text(
+        &mut self,
+        details: &mut TextDetails,
+        font: &Rc<Font>,
+    ) -> Result<Rc<Texture<'l>>, String>;
+}
+
+impl<'l, T> TextTextureManager<'l> for TextureManager<'l, T> {
+    //noinspection RsWrongLifetimeParametersNumber
+    fn load_text(
         &mut self,
         details: &mut TextDetails,
         font: &Rc<Font>,

src/renderer/mod.rs

@@ -1,90 +1,5 @@
-use crate::app::WindowCanvas;
-use crate::config::Config;
-use crate::renderer::managers::TextDetails;
-use crate::renderer::managers::{FontManager, TextureManager};
-use sdl2::rect::{Point, Rect};
-use sdl2::render::{Texture, TextureCreator};
-use sdl2::ttf::Sdl2TtfContext;
-use sdl2::video::WindowContext;
-use std::rc::Rc;
-use std::sync::*;
-
 pub mod managers;
+pub mod renderer;
 
-pub struct Renderer<'a> {
-    config: Arc<RwLock<Config>>,
-    font_manager: FontManager<'a>,
-    texture_manager: TextureManager<'a, WindowContext>,
-    scroll: Point,
-}
-
-impl<'a> Renderer<'a> {
-    pub fn new(
-        config: Arc<RwLock<Config>>,
-        font_context: &'a Sdl2TtfContext,
-        texture_creator: &'a TextureCreator<WindowContext>,
-    ) -> Self {
-        Self {
-            config,
-            font_manager: FontManager::new(&font_context),
-            texture_manager: TextureManager::new(&texture_creator),
-            scroll: (0, 0).into(),
-        }
-    }
-
-    pub fn config(&self) -> &Arc<RwLock<Config>> {
-        &self.config
-    }
-
-    pub fn font_manager(&mut self) -> &mut FontManager<'a> {
-        &mut self.font_manager
-    }
-
-    pub fn texture_manager(&mut self) -> &mut TextureManager<'a, WindowContext> {
-        &mut self.texture_manager
-    }
-
-    pub fn scroll(&self) -> &Point {
-        &self.scroll
-    }
-
-    pub fn render_texture(
-        &mut self,
-        canvas: &mut WindowCanvas,
-        texture: &Rc<Texture>,
-        src: &Rect,
-        dest: &Rect,
-    ) {
-        canvas
-            .copy_ex(
-                texture,
-                Some(src.clone()),
-                Some(dest.clone()),
-                0.0,
-                None,
-                false,
-                false,
-            )
-            .unwrap();
-    }
-
-    pub fn render_text(&mut self, details: TextDetails) -> Option<Rc<Texture>> {
-        let font = self.font_manager.load(&details.font).unwrap();
-        let surface = font.render(details.text.as_str()).blended(details.color);
-        let surface = if let Ok(s) = surface {
-            s
-        } else {
-            return None;
-        };
-        let texture = self
-            .texture_manager
-            .loader()
-            .create_texture_from_surface(&surface);
-        let texture = if let Ok(t) = texture {
-            Rc::new(t)
-        } else {
-            return None;
-        };
-        Some(texture)
-    }
-}
+pub use crate::renderer::managers::*;
+pub use crate::renderer::renderer::*;

src/renderer/renderer.rs

@@ -0,0 +1,45 @@
+use crate::app::WindowCanvas as WC;
+use crate::config::{Config, ConfigAccess, ConfigHolder};
+use crate::renderer::managers::*;
+use sdl2::rect::{Point, Rect};
+use sdl2::render::{Texture, TextureCreator};
+use sdl2::ttf::Sdl2TtfContext;
+use sdl2::video::WindowContext as WinCtxt;
+use std::rc::Rc;
+use std::sync::*;
+
+pub struct Renderer<'l> {
+    config: ConfigAccess,
+    font_manager: FontManager<'l>,
+    texture_manager: TextureManager<'l, WinCtxt>,
+}
+
+impl<'l> Renderer<'l> {
+    pub fn new(
+        config: ConfigAccess,
+        font_context: &'l Sdl2TtfContext,
+        texture_creator: &'l TextureCreator<WinCtxt>,
+    ) -> Self {
+        Self {
+            config,
+            font_manager: FontManager::new(&font_context),
+            texture_manager: TextureManager::new(&texture_creator),
+        }
+    }
+}
+
+impl<'l> ManagersHolder<'l> for Renderer<'l> {
+    fn font_manager(&mut self) -> &mut FontManager<'l> {
+        &mut self.font_manager
+    }
+
+    fn texture_manager(&mut self) -> &mut TextureManager<'l, WinCtxt> {
+        &mut self.texture_manager
+    }
+}
+
+impl<'l> ConfigHolder for Renderer<'l> {
+    fn config(&self) -> &ConfigAccess {
+        &self.config
+    }
+}

src/tests.rs

@@ -0,0 +1,28 @@
+#[cfg(test)]
+pub mod support {
+    use crate::config::*;
+    use crate::renderer::*;
+    use sdl2::render::{Canvas, WindowCanvas};
+    use sdl2::*;
+    use sdl2::{Sdl, TimerSubsystem, VideoSubsystem};
+    use std::borrow::*;
+    use std::sync::*;
+
+    pub fn build_config() -> Arc<RwLock<Config>> {
+        Arc::new(RwLock::new(Config::new()))
+    }
+
+    pub fn build_canvas() -> WindowCanvas {
+        let sdl_context = sdl2::init().unwrap();
+        let video_subsystem = sdl_context.video().unwrap();
+
+        let window = video_subsystem
+            .window("Test", 1, 1)
+            .borderless()
+            .opengl()
+            .build()
+            .unwrap();
+
+        window.into_canvas().accelerated().build().unwrap()
+    }
+}

src/ui/caret.rs

@@ -1,248 +0,0 @@
-use crate::app::{UpdateResult as UR, WindowCanvas as WC};
-use crate::config::Config;
-use crate::renderer::Renderer;
-use crate::ui::text_character::TextCharacter;
-use crate::ui::*;
-use sdl2::pixels::Color;
-use sdl2::rect::{Point, Rect};
-use sdl2::render::Texture;
-use std::ops::Deref;
-use std::rc::Rc;
-use std::sync::*;
-
-#[derive(Clone, Debug, PartialEq)]
-pub enum CaretState {
-    Bright,
-    Blur,
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub enum MoveDirection {
-    Left,
-    Right,
-    Up,
-    Down,
-}
-
-//#[derive(Clone, Debug, PartialEq)]
-//pub enum CaretLocation {
-//    FirstLineFirstCharacter,
-//    FirstLine(usize), // with character location
-//    LastLineFirstCharacter,
-//    LastLine(usize), // with character location
-//    FirstCharacter(usize),// with line number
-//    LastCharacter(usize), // with line number
-//    Other(usize, usize), // with line number and character number
-//}
-
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub struct CaretPosition {
-    text_position: usize,
-    line_number: usize,
-    line_position: usize,
-}
-
-impl CaretPosition {
-    pub fn new(text_position: usize, line_number: usize, line_position: usize) -> Self {
-        Self {
-            text_position,
-            line_number,
-            line_position,
-        }
-    }
-
-    pub fn text_position(&self) -> usize {
-        self.text_position.clone()
-    }
-
-    pub fn line_number(&self) -> usize {
-        self.line_number.clone()
-    }
-
-    pub fn line_position(&self) -> usize {
-        self.line_position.clone()
-    }
-
-    pub fn reset(&mut self) {
-        self.text_position = 0;
-        self.line_number = 0;
-        self.line_position = 0;
-    }
-
-    pub fn set_text_position(&mut self, n: usize) {
-        self.text_position = n;
-    }
-
-    pub fn set_line_number(&mut self, n: usize) {
-        self.line_number = n;
-    }
-
-    pub fn set_line_position(&mut self, n: usize) {
-        self.line_position = n;
-    }
-
-    pub fn moved(&self, text_position: i32, line_number: i32, line_position: i32) -> Self {
-        Self {
-            text_position: (self.text_position as i32 + text_position) as usize,
-            line_number: (self.line_number as i32 + line_number) as usize,
-            line_position: (self.line_position as i32 + line_position) as usize,
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub struct CaretRenderPosition {
-    dest: Rect,
-    reset_position: Rect,
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub struct CaretColor {
-    bright: Color,
-    blur: Color,
-}
-
-impl CaretColor {
-    pub fn new(bright: Color, blur: Color) -> Self {
-        Self { bright, blur }
-    }
-
-    pub fn bright(&self) -> &Color {
-        &self.bright
-    }
-
-    pub fn blur(&self) -> &Color {
-        &self.blur
-    }
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub struct Caret {
-    pending: bool,
-    blink_delay: u8,
-    state: CaretState,
-    position: CaretPosition,
-    dest: Rect,
-    colors: CaretColor,
-}
-
-impl Caret {
-    pub fn new(config: Arc<RwLock<Config>>) -> Self {
-        let read_config = config.read().unwrap();
-        let bright = read_config.theme().caret().bright().color().into();
-        let blur = read_config.theme().caret().blur().color().into();
-        Self {
-            state: CaretState::Bright,
-            blink_delay: 0,
-            dest: Rect::new(0, 0, 6, 0),
-            colors: CaretColor { bright, blur },
-            pending: true,
-            position: CaretPosition {
-                text_position: 0,
-                line_number: 0,
-                line_position: 0,
-            },
-        }
-    }
-
-    fn toggle_state(&mut self) {
-        self.state = if self.state == CaretState::Bright {
-            CaretState::Blur
-        } else {
-            CaretState::Bright
-        };
-    }
-
-    pub fn reset_caret(&mut self) {
-        self.dest.set_x(0);
-        self.dest.set_y(0);
-        self.position.reset();
-    }
-
-    pub fn move_caret(&mut self, position: CaretPosition, pos: Point) {
-        self.position = position;
-        self.dest.set_x(pos.x());
-        self.dest.set_y(pos.y());
-    }
-
-    pub fn dest(&self) -> &Rect {
-        &self.dest
-    }
-
-    pub fn position(&self) -> &CaretPosition {
-        &self.position
-    }
-}
-
-impl Deref for Caret {
-    type Target = CaretPosition;
-
-    fn deref(&self) -> &<Self as Deref>::Target {
-        self.position()
-    }
-}
-
-impl Render for Caret {
-    fn render(&self, canvas: &mut WC, _renderer: &mut Renderer, parent: Parent) -> UR {
-        let dest = match parent {
-            Some(parent) => move_render_point(parent.render_start_point(), self.dest()),
-            None => self.dest().clone(),
-        };
-        let start = Point::new(dest.x(), dest.y());
-        let end = Point::new(dest.x(), dest.y() + dest.height() as i32);
-        let color = match self.state {
-            CaretState::Bright => self.colors.bright(),
-            CaretState::Blur => self.colors.blur(),
-        }
-        .clone();
-        canvas.set_draw_color(color);
-        canvas
-            .draw_line(start, end)
-            .unwrap_or_else(|_| panic!("Failed to draw a caret"));
-        UR::NoOp
-    }
-
-    fn prepare_ui(&mut self, renderer: &mut Renderer) {
-        if !self.pending {
-            return;
-        }
-
-        if let Some(rect) = get_text_character_rect('W', renderer) {
-            self.dest.set_height(rect.height());
-        }
-        self.pending = false;
-    }
-}
-
-impl Update for Caret {
-    fn update(&mut self, _ticks: i32, _context: &UpdateContext) -> UR {
-        self.blink_delay += 1;
-        if self.blink_delay >= 30 {
-            self.blink_delay = 0;
-            self.toggle_state();
-        }
-        UR::NoOp
-    }
-}
-
-impl ClickHandler for Caret {
-    fn on_left_click(&mut self, _point: &Point, _context: &UpdateContext) -> UR {
-        UR::NoOp
-    }
-
-    fn is_left_click_target(&self, point: &Point, context: &UpdateContext) -> bool {
-        is_in_rect(
-            point,
-            &match context {
-                &UpdateContext::ParentPosition(p) => move_render_point(p, self.dest()),
-                _ => self.dest().clone(),
-            },
-        )
-    }
-}
-
-impl RenderBox for Caret {
-    fn render_start_point(&self) -> Point {
-        self.dest().top_left()
-    }
-}

src/ui/caret/caret.rs

@@ -0,0 +1,322 @@
+use crate::app::{UpdateResult as UR, WindowCanvas as WC};
+use crate::config::*;
+use crate::renderer::*;
+use crate::ui::text_character::TextCharacter;
+use crate::ui::*;
+use sdl2::pixels::Color;
+use sdl2::rect::{Point, Rect};
+use sdl2::render::Texture;
+use std::ops::Deref;
+use std::sync::*;
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Caret {
+    pending: bool,
+    blink_delay: u8,
+    state: CaretState,
+    position: CaretPosition,
+    dest: Rect,
+    colors: CaretColor,
+}
+
+impl Caret {
+    pub fn new(config: ConfigAccess) -> Self {
+        let read_config = config.read().unwrap();
+        let bright = read_config.theme().caret().bright().color().into();
+        let blur = read_config.theme().caret().blur().color().into();
+        Self {
+            state: CaretState::Bright,
+            blink_delay: 0,
+            dest: Rect::new(0, 0, 6, 0),
+            colors: CaretColor::new(bright, blur),
+            pending: true,
+            position: CaretPosition::new(0, 0, 0),
+        }
+    }
+
+    fn toggle_state(&mut self) {
+        self.state = match self.state {
+            CaretState::Bright => CaretState::Blur,
+            CaretState::Blur => CaretState::Bright,
+        };
+    }
+
+    pub fn reset_caret(&mut self) {
+        self.dest.set_x(0);
+        self.dest.set_y(0);
+        self.position.reset();
+    }
+
+    pub fn move_caret(&mut self, position: CaretPosition, pos: Point) {
+        self.position = position;
+        self.dest.set_x(pos.x());
+        self.dest.set_y(pos.y());
+    }
+
+    pub fn position(&self) -> &CaretPosition {
+        &self.position
+    }
+
+    pub fn state(&self) -> &CaretState {
+        &self.state
+    }
+}
+
+impl Deref for Caret {
+    type Target = CaretPosition;
+
+    fn deref(&self) -> &<Self as Deref>::Target {
+        self.position()
+    }
+}
+
+impl Render for Caret {
+    fn render(&self, canvas: &mut WC, _renderer: &mut Renderer, parent: Parent) {
+        let dest = match parent {
+            Some(parent) => move_render_point(parent.render_start_point(), self.dest()),
+            None => self.dest().clone(),
+        };
+        let start = Point::new(dest.x(), dest.y());
+        let end = Point::new(dest.x(), dest.y() + dest.height() as i32);
+        let color = match self.state {
+            CaretState::Bright => self.colors.bright(),
+            CaretState::Blur => self.colors.blur(),
+        }
+        .clone();
+        canvas.set_draw_color(color);
+        canvas
+            .draw_line(start, end)
+            .unwrap_or_else(|_| panic!("Failed to draw a caret"));
+    }
+
+    fn prepare_ui(&mut self, renderer: &mut Renderer) {
+        if !self.pending {
+            return;
+        }
+
+        if let Some(rect) = get_text_character_rect('W', renderer) {
+            self.dest.set_height(rect.height());
+        }
+        self.pending = false;
+    }
+}
+
+impl Update for Caret {
+    fn update(&mut self, _ticks: i32, _context: &UpdateContext) -> UR {
+        self.blink_delay += 1;
+        if self.blink_delay >= 30 {
+            self.blink_delay = 0;
+            self.toggle_state();
+        }
+        UR::NoOp
+    }
+}
+
+impl ClickHandler for Caret {
+    fn on_left_click(&mut self, _point: &Point, _context: &UpdateContext) -> UR {
+        UR::NoOp
+    }
+
+    fn is_left_click_target(&self, point: &Point, context: &UpdateContext) -> bool {
+        is_in_rect(
+            point,
+            &match context {
+                &UpdateContext::ParentPosition(p) => move_render_point(p, self.dest()),
+                _ => self.dest().clone(),
+            },
+        )
+    }
+}
+
+impl RenderBox for Caret {
+    fn render_start_point(&self) -> Point {
+        self.dest().top_left()
+    }
+
+    fn dest(&self) -> &Rect {
+        &self.dest
+    }
+}
+
+#[cfg(test)]
+mod test_own_methods {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn assert_move_caret() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+        widget.move_caret(widget.moved(10, 21, 34), Point::new(10, 20));
+        let result = (
+            widget.text_position(),
+            widget.line_number(),
+            widget.line_position(),
+            widget.dest().clone(),
+        );
+        let expected = (10, 21, 34, Rect::new(10, 20, 6, 1));
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_reset() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+        widget.reset_caret();
+        let result = (
+            widget.text_position(),
+            widget.line_number(),
+            widget.line_position(),
+            widget.dest().clone(),
+        );
+        let expected = (0, 0, 0, Rect::new(0, 0, 6, 1));
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_toggle_state() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+
+        let old = widget.state().clone();
+        widget.toggle_state();
+        let new = widget.state().clone();
+        assert_ne!(old, new);
+
+        let old = widget.state().clone();
+        widget.toggle_state();
+        let new = widget.state().clone();
+        assert_ne!(old, new);
+
+        let old = widget.state().clone();
+        widget.toggle_state();
+        let new = widget.state().clone();
+        assert_ne!(old, new);
+    }
+}
+
+#[cfg(test)]
+mod test_deref {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_deref_text_position() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+        widget.move_caret(widget.moved(10, 21, 34), Point::new(0, 0));
+        let result = widget.text_position();
+        let expected: usize = 10;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_deref_line_number() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+        widget.move_caret(widget.moved(10, 21, 34), Point::new(0, 0));
+        let result = widget.line_number();
+        let expected: usize = 21;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn must_deref_line_position() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+        widget.move_caret(widget.moved(10, 21, 34), Point::new(0, 0));
+        let result = widget.line_position();
+        let expected: usize = 34;
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_render_box {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_return_top_left_point() {
+        let config = support::build_config();
+        let widget = Caret::new(Arc::clone(&config));
+        let result = widget.render_start_point();
+        let expected = Point::new(0, 0);
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_click_handler {
+    use crate::app::*;
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn refute_when_not_click_target() {
+        let config = support::build_config();
+        let widget = Caret::new(Arc::clone(&config));
+        let point = Point::new(9999, 9999);
+        let context = UpdateContext::Nothing;
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, false);
+    }
+
+    #[test]
+    fn assert_when_click_target() {
+        let config = support::build_config();
+        let widget = Caret::new(Arc::clone(&config));
+
+        let point = Point::new(0, 0);
+        let context = UpdateContext::Nothing;
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, true);
+    }
+
+    #[test]
+    fn refute_when_not_click_target_because_parent() {
+        let config = support::build_config();
+        let widget = Caret::new(Arc::clone(&config));
+        let point = Point::new(20, 30);
+        let context = UpdateContext::ParentPosition(Point::new(9999, 9999));
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, false);
+    }
+
+    #[test]
+    fn assert_when_click_target_because_parent() {
+        let config = support::build_config();
+        let widget = Caret::new(Arc::clone(&config));
+        let point = Point::new(10, 10);
+        let context = UpdateContext::ParentPosition(Point::new(10, 10));
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, true);
+    }
+
+    #[test]
+    fn assert_on_click_do_nothing() {
+        let config = support::build_config();
+        let mut widget = Caret::new(Arc::clone(&config));
+        let point = Point::new(12, 34);
+        let context = UpdateContext::ParentPosition(Point::new(678, 293));
+        let result = widget.on_left_click(&point, &context);
+        let expected = UpdateResult::NoOp;
+        assert_eq!(result, expected);
+    }
+}

src/ui/caret/caret_color.rs

@@ -0,0 +1,43 @@
+use sdl2::pixels::Color;
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct CaretColor {
+    bright: Color,
+    blur: Color,
+}
+
+impl CaretColor {
+    pub fn new(bright: Color, blur: Color) -> Self {
+        Self { bright, blur }
+    }
+
+    pub fn bright(&self) -> &Color {
+        &self.bright
+    }
+
+    pub fn blur(&self) -> &Color {
+        &self.blur
+    }
+}
+
+#[cfg(test)]
+mod test_getters {
+    use super::*;
+    use sdl2::pixels::*;
+
+    #[test]
+    fn assert_bright() {
+        let target = CaretColor::new(Color::RGBA(1, 2, 3, 4), Color::RGBA(5, 6, 7, 8));
+        let result = target.bright().clone();
+        let expected = Color::RGBA(1, 2, 3, 4);
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_blur() {
+        let target = CaretColor::new(Color::RGBA(1, 2, 3, 4), Color::RGBA(5, 6, 7, 8));
+        let result = target.blur().clone();
+        let expected = Color::RGBA(5, 6, 7, 8);
+        assert_eq!(result, expected);
+    }
+}

src/ui/caret/caret_position.rs

@@ -0,0 +1,123 @@
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct CaretPosition {
+    text_position: usize,
+    line_number: usize,
+    line_position: usize,
+}
+
+impl CaretPosition {
+    pub fn new(text_position: usize, line_number: usize, line_position: usize) -> Self {
+        Self {
+            text_position,
+            line_number,
+            line_position,
+        }
+    }
+
+    pub fn text_position(&self) -> usize {
+        self.text_position
+    }
+
+    pub fn line_number(&self) -> usize {
+        self.line_number
+    }
+
+    pub fn line_position(&self) -> usize {
+        self.line_position
+    }
+
+    pub fn reset(&mut self) {
+        self.text_position = 0;
+        self.line_number = 0;
+        self.line_position = 0;
+    }
+
+    pub fn set_text_position(&mut self, n: usize) {
+        self.text_position = n;
+    }
+
+    pub fn set_line_number(&mut self, n: usize) {
+        self.line_number = n;
+    }
+
+    pub fn set_line_position(&mut self, n: usize) {
+        self.line_position = n;
+    }
+
+    pub fn moved(&self, text_position: i32, line_number: i32, line_position: i32) -> Self {
+        Self {
+            text_position: (self.text_position as i32 + text_position) as usize,
+            line_number: (self.line_number as i32 + line_number) as usize,
+            line_position: (self.line_position as i32 + line_position) as usize,
+        }
+    }
+}
+
+#[cfg(test)]
+mod test_getters {
+    use super::*;
+
+    #[test]
+    fn assert_text_position() {
+        let target = CaretPosition::new(1, 2, 3);
+        let result = target.text_position();
+        let expected = 1;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_line_number() {
+        let target = CaretPosition::new(1, 2, 3);
+        let result = target.line_number();
+        let expected = 2;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_line_position() {
+        let target = CaretPosition::new(1, 2, 3);
+        let result = target.line_position();
+        let expected = 3;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_moved() {
+        let target = CaretPosition::new(1, 2, 3);
+        let result = target.moved(1, 2, 3);
+        let expected = CaretPosition::new(2, 4, 6);
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_setters {
+    use super::*;
+
+    #[test]
+    fn assert_text_position() {
+        let mut target = CaretPosition::new(1, 2, 3);
+        target.set_text_position(100);
+        let result = target.text_position();
+        let expected = 100;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_line_number() {
+        let mut target = CaretPosition::new(1, 2, 3);
+        target.set_line_number(200);
+        let result = target.line_number();
+        let expected = 200;
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_line_position() {
+        let mut target = CaretPosition::new(1, 2, 3);
+        target.set_line_position(300);
+        let result = target.line_position();
+        let expected = 300;
+        assert_eq!(result, expected);
+    }
+}

src/ui/caret/mod.rs

@@ -0,0 +1,21 @@
+#[derive(Clone, Debug, PartialEq)]
+pub enum CaretState {
+    Bright,
+    Blur,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub enum MoveDirection {
+    Left,
+    Right,
+    Up,
+    Down,
+}
+
+pub mod caret;
+pub mod caret_color;
+pub mod caret_position;
+
+pub use crate::ui::caret::caret::*;
+pub use crate::ui::caret::caret_color::*;
+pub use crate::ui::caret::caret_position::*;

src/ui/file/editor_file.rs

@@ -13,7 +13,7 @@ use crate::ui::*;
 pub struct EditorFile {
     path: String,
     sections: Vec<EditorFileSection>,
-    render_position: Rect,
+    dest: Rect,
     buffer: String,
     config: Arc<RwLock<Config>>,
     line_height: u32,
@@ -42,7 +42,7 @@ impl EditorFile {
         Self {
             path,
             sections,
-            render_position,
+            dest: render_position,
             buffer,
             config,
             line_height: 0,
@@ -66,7 +66,7 @@ impl EditorFile {
     }
 
     pub fn render_position(&self) -> &Rect {
-        &self.render_position
+        &self.dest
     }
 
     pub fn get_character_at(&self, index: usize) -> Option<TextCharacter> {
@@ -119,11 +119,10 @@ impl EditorFile {
 }
 
 impl Render for EditorFile {
-    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) -> UR {
+    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) {
         for section in self.sections.iter() {
             section.render(canvas, renderer, parent);
         }
-        UR::NoOp
     }
 
     fn prepare_ui(&mut self, renderer: &mut Renderer) {
@@ -179,6 +178,10 @@ impl ClickHandler for EditorFile {
 
 impl RenderBox for EditorFile {
     fn render_start_point(&self) -> Point {
-        self.render_position.top_left()
+        self.dest.top_left()
+    }
+
+    fn dest(&self) -> &Rect {
+        &self.dest
     }
 }

src/ui/file/editor_file_section.rs

@@ -101,11 +101,10 @@ impl EditorFileSection {
 }
 
 impl Render for EditorFileSection {
-    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) -> UR {
+    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) {
         for token in self.tokens.iter() {
             token.render(canvas, renderer, parent);
         }
-        UR::NoOp
     }
 
     fn prepare_ui(&mut self, renderer: &mut Renderer) {

src/ui/file/editor_file_token.rs

@@ -1,8 +1,8 @@
 use crate::app::{UpdateResult as UR, WindowCanvas as WC};
-use crate::config::Config;
+use crate::config::*;
 use crate::lexer::TokenType;
 use crate::renderer::managers::{FontDetails, TextDetails};
-use crate::renderer::Renderer;
+use crate::renderer::*;
 use crate::ui::*;
 use sdl2::pixels::Color;
 use sdl2::rect::{Point, Rect};
@@ -19,7 +19,6 @@ impl TokenType {
             &TokenType::Whitespace { .. } => ch.whitespace().color().into(),
             &TokenType::Keyword { .. } => ch.keyword().color().into(),
             &TokenType::String { .. } => ch.string().color().into(),
-            &TokenType::Number { .. } => ch.number().color().into(),
             &TokenType::Identifier { .. } => ch.identifier().color().into(),
             &TokenType::Literal { .. } => ch.literal().color().into(),
             &TokenType::Comment { .. } => ch.comment().color().into(),
@@ -113,14 +112,13 @@ impl Render for EditorFileToken {
      * Must first create targets so even if new line appear renderer will know
      * where move render starting point
      */
-    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) -> UR {
+    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) {
         if self.token_type.is_new_line() {
-            return UR::NoOp;
+            return;
         }
         for text_character in self.characters.iter() {
             text_character.render(canvas, renderer, parent);
         }
-        UR::NoOp
     }
 
     fn prepare_ui(&mut self, renderer: &mut Renderer) {

src/ui/file_editor.rs

@@ -6,6 +6,7 @@ use std::sync::*;
 
 use crate::app::*;
 use crate::app::{UpdateResult as UR, WindowCanvas as WS};
+use crate::config::*;
 use crate::ui::*;
 
 pub struct FileEditor {
@@ -13,11 +14,11 @@ pub struct FileEditor {
     scroll: Point,
     caret: Caret,
     file: Option<EditorFile>,
-    config: Arc<RwLock<Config>>,
+    config: ConfigAccess,
 }
 
 impl FileEditor {
-    pub fn new(config: Arc<RwLock<Config>>) -> Self {
+    pub fn new(config: ConfigAccess) -> Self {
         let dest = {
             let c = config.read().unwrap();
             Rect::new(
@@ -36,10 +37,6 @@ impl FileEditor {
         }
     }
 
-    pub fn config(&self) -> &Arc<RwLock<Config>> {
-        &self.config
-    }
-
     pub fn caret(&self) -> &Caret {
         &self.caret
     }
@@ -166,13 +163,13 @@ impl FileEditor {
 }
 
 impl Render for FileEditor {
-    fn render(&self, canvas: &mut WS, renderer: &mut Renderer, _parent: Parent) -> UR {
+    fn render(&self, canvas: &mut WS, renderer: &mut Renderer, _parent: Parent) {
         canvas.set_clip_rect(self.dest.clone());
         match self.file() {
             Some(file) => file.render(canvas, renderer, Some(self)),
-            _ => UR::NoOp,
+            _ => (),
         };
-        self.caret.render(canvas, renderer, Some(self))
+        self.caret.render(canvas, renderer, Some(self));
     }
 
     fn prepare_ui(&mut self, renderer: &mut Renderer) {
@@ -229,6 +226,16 @@ impl RenderBox for FileEditor {
     fn render_start_point(&self) -> Point {
         self.dest.top_left() + self.scroll
     }
+
+    fn dest(&self) -> &Rect {
+        &self.dest
+    }
+}
+
+impl ConfigHolder for FileEditor {
+    fn config(&self) -> &ConfigAccess {
+        &self.config
+    }
 }
 
 #[cfg(test)]
@@ -256,35 +263,4 @@ mod tests {
         assert_eq!(file.path(), first_file.path());
         assert_eq!(file.buffer(), first_file.buffer());
     }
-
-    #[test]
-    fn add_text() {
-        let config = Arc::new(RwLock::new(Config::new()));
-        let sdl_context = sdl2::init().unwrap();
-        let video_subsystem = sdl_context.video().unwrap();
-        let window = video_subsystem
-            .window("Test", 1, 1)
-            .borderless()
-            .opengl()
-            .build()
-            .unwrap();
-        let canvas = window.into_canvas().accelerated().build().unwrap();
-        let font_context = sdl2::ttf::init().unwrap();
-        let texture_creator = canvas.texture_creator();
-        let mut renderer = Renderer::new(config.clone(), &font_context, &texture_creator);
-
-        let mut editor = FileEditor::new(Arc::clone(&config));
-        let mut file = EditorFile::new("./foo.txt".to_string(), "foo".to_string(), config.clone());
-        file.prepare_ui(&mut renderer);
-        assert_eq!(editor.open_file(file).is_none(), true);
-        assert_eq!(editor.caret().position().text_position(), 0);
-        assert_eq!(editor.file().is_some(), true);
-        assert_eq!(editor.file().unwrap().sections().len(), 1);
-        assert_eq!(editor.file().unwrap().get_character_at(0).is_some(), true);
-
-        editor.insert_text("z".to_string(), &mut renderer);
-        assert_eq!(editor.caret().position().text_position(), 1);
-        assert_eq!(editor.file().is_some(), true);
-        assert_eq!(editor.file().unwrap().buffer(), "zfoo".to_string());
-    }
 }

src/ui/menu_bar.rs

@@ -1,6 +1,6 @@
 use crate::app::{UpdateResult as UR, WindowCanvas as WC};
-use crate::config::Config;
-use crate::renderer::Renderer;
+use crate::config::*;
+use crate::renderer::*;
 use crate::ui::*;
 use sdl2::pixels::Color;
 use sdl2::rect::{Point, Rect};
@@ -11,33 +11,30 @@ pub struct MenuBar {
     border_color: Color,
     background_color: Color,
     dest: Rect,
-    config: Arc<RwLock<Config>>,
-    pending: bool,
+    config: ConfigAccess,
 }
 
 impl MenuBar {
-    pub fn new(config: Arc<RwLock<Config>>) -> Self {
-        let background_color = { config.read().unwrap().theme().background().into() };
+    pub fn new(config: ConfigAccess) -> Self {
+        let (background_color, w, h): (Color, u32, u16) = {
+            let c = config.read().unwrap();
+            (c.theme().background().into(), c.width(), c.menu_height())
+        };
         Self {
             border_color: Color::RGB(10, 10, 10),
             background_color,
-            dest: Rect::new(0, 0, 0, 0),
+            dest: Rect::new(0, 0, w as u32, h as u32),
             config,
-            pending: true,
         }
     }
 
     pub fn background_color(&self) -> &Color {
         &self.background_color
     }
-
-    pub fn dest(&self) -> &Rect {
-        &self.dest
-    }
 }
 
 impl Render for MenuBar {
-    fn render(&self, canvas: &mut WC, _renderer: &mut Renderer, parent: Parent) -> UR {
+    fn render(&self, canvas: &mut WC, _renderer: &mut Renderer, parent: Parent) {
         canvas.set_clip_rect(self.dest.clone());
         canvas.set_draw_color(self.background_color.clone());
         canvas
@@ -54,18 +51,12 @@ impl Render for MenuBar {
                 Some(parent) => move_render_point(parent.render_start_point(), self.dest()),
             })
             .unwrap_or_else(|_| panic!("Failed to draw main menu background"));
-
-        UR::NoOp
     }
 
     fn prepare_ui(&mut self, _renderer: &mut Renderer) {
-        if !self.pending {
-            return;
-        }
         let width = self.config.read().unwrap().width();
         let height = self.config.read().unwrap().menu_height() as u32;
         self.dest = Rect::new(0, 0, width, height);
-        self.pending = false;
     }
 }
 
@@ -79,17 +70,15 @@ impl Update for MenuBar {
 
 impl ClickHandler for MenuBar {
     fn on_left_click(&mut self, _point: &Point, _context: &UpdateContext) -> UR {
-        unimplemented!()
+        UR::NoOp
     }
 
     fn is_left_click_target(&self, point: &Point, context: &UpdateContext) -> bool {
-        is_in_rect(
-            point,
-            &match context {
-                &UpdateContext::ParentPosition(p) => move_render_point(p, self.dest()),
-                _ => self.dest().clone(),
-            },
-        )
+        let rect = match context.clone() {
+            UpdateContext::ParentPosition(p) => move_render_point(p.clone(), self.dest()),
+            _ => self.dest().clone(),
+        };
+        is_in_rect(point, &rect)
     }
 }
 
@@ -97,4 +86,128 @@ impl RenderBox for MenuBar {
     fn render_start_point(&self) -> Point {
         self.dest.top_left()
     }
+
+    fn dest(&self) -> &Rect {
+        &self.dest
+    }
+}
+
+#[cfg(test)]
+mod test_getters {
+    use crate::app::*;
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn assert_background_color() {
+        let config = support::build_config();
+        let widget = MenuBar::new(Arc::clone(&config));
+        let result = widget.background_color().clone();
+        let expected = Color::RGBA(18, 18, 18, 0);
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn assert_dest() {
+        let config = support::build_config();
+        let (w, h) = {
+            let c = config.read().unwrap();
+            (c.width() as u32, c.menu_height() as u32)
+        };
+        let widget = MenuBar::new(Arc::clone(&config));
+        let result = widget.dest().clone();
+        let expected = Rect::new(0, 0, w, h);
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_render_box {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_return_top_left_point() {
+        let config = support::build_config();
+        let widget = MenuBar::new(Arc::clone(&config));
+        let result = widget.render_start_point();
+        let expected = Point::new(0, 0);
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_click_handler {
+    use crate::app::*;
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn refute_when_not_click_target() {
+        let config = support::build_config();
+        let widget = MenuBar::new(Arc::clone(&config));
+        let point = Point::new(9999, 9999);
+        let context = UpdateContext::Nothing;
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, false);
+    }
+
+    #[test]
+    fn assert_when_click_target() {
+        let config = support::build_config();
+        let widget = MenuBar::new(Arc::clone(&config));
+        let point = Point::new(20, 30);
+        let context = UpdateContext::Nothing;
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, true);
+    }
+
+    #[test]
+    fn refute_when_not_click_target_because_parent() {
+        let config = support::build_config();
+        let widget = MenuBar::new(Arc::clone(&config));
+        let point = Point::new(20, 30);
+        let context = UpdateContext::ParentPosition(Point::new(9999, 9999));
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, false);
+    }
+
+    #[test]
+    fn assert_when_click_target_because_parent() {
+        let config = support::build_config();
+        let (w, h) = {
+            (
+                config.read().unwrap().width(),
+                config.read().unwrap().menu_height(),
+            )
+        };
+        let widget = MenuBar::new(Arc::clone(&config));
+        let point = Point::new(w as i32 + 120, h as i32 + 130);
+        let context = UpdateContext::ParentPosition(Point::new(130, 140));
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, true);
+    }
+
+    #[test]
+    fn assert_on_click_do_nothing() {
+        let config = support::build_config();
+        let mut widget = MenuBar::new(Arc::clone(&config));
+        let point = Point::new(12, 34);
+        let context = UpdateContext::ParentPosition(Point::new(678, 293));
+        let result = widget.on_left_click(&point, &context);
+        let expected = UpdateResult::NoOp;
+        assert_eq!(result, expected);
+    }
 }

src/ui/mod.rs

@@ -1,8 +1,8 @@
 use sdl2::rect::{Point, Rect};
 
-use crate::app::{UpdateResult, WindowCanvas};
-use crate::config::Config;
-use crate::renderer::managers::FontDetails;
+use crate::app::{UpdateResult as UR, WindowCanvas as WC};
+use crate::config::*;
+use crate::renderer::managers::*;
 use crate::renderer::Renderer;
 
 pub mod caret;
@@ -30,41 +30,32 @@ pub enum UpdateContext<'l> {
 
 #[inline]
 pub fn is_in_rect(point: &Point, rect: &Rect) -> bool {
-    let start = rect.top_left();
-    let end = Point::new(
-        rect.x() + (rect.width() as i32),
-        rect.y() + (rect.height() as i32),
-    );
-    start.x() <= point.x() && start.y() <= point.y() && end.x() >= point.x() && end.y() >= point.y()
+    rect.contains_point(point.clone())
 }
 
-pub fn get_text_character_rect(c: char, renderer: &mut Renderer) -> Option<Rect> {
-    let font_details = FontDetails::new(
-        renderer
-            .config()
-            .read()
-            .unwrap()
-            .editor_config()
-            .font_path()
-            .as_str(),
-        renderer
-            .config()
-            .read()
-            .unwrap()
-            .editor_config()
-            .character_size()
-            .clone(),
-    );
-    let font = renderer
+#[inline]
+pub fn build_font_details<T>(config_holder: &T) -> FontDetails
+where
+    T: ConfigHolder,
+{
+    let c = config_holder.config().read().unwrap();
+    FontDetails::new(
+        c.editor_config().font_path().as_str(),
+        c.editor_config().character_size().clone(),
+    )
+}
+
+pub fn get_text_character_rect<'l, T>(c: char, renderer: &mut T) -> Option<Rect>
+where
+    T: ManagersHolder<'l> + ConfigHolder,
+{
+    let font_details = build_font_details(renderer);
+    renderer
         .font_manager()
         .load(&font_details)
-        .unwrap_or_else(|_| panic!("Font not found {:?}", font_details));
-
-    if let Ok((width, height)) = font.size_of_char(c) {
-        Some(Rect::new(0, 0, width, height))
-    } else {
-        None
-    }
+        .ok()
+        .and_then(|font| font.size_of_char(c).ok())
+        .and_then(|(width, height)| Some(Rect::new(0, 0, width, height)))
 }
 
 #[inline]
@@ -73,26 +64,73 @@ pub fn move_render_point(p: Point, d: &Rect) -> Rect {
 }
 
 pub trait Render {
-    fn render(
-        &self,
-        canvas: &mut WindowCanvas,
-        renderer: &mut Renderer,
-        parent: Parent,
-    ) -> UpdateResult;
+    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent);
 
     fn prepare_ui(&mut self, renderer: &mut Renderer);
 }
 
 pub trait Update {
-    fn update(&mut self, ticks: i32, context: &UpdateContext) -> UpdateResult;
+    fn update(&mut self, ticks: i32, context: &UpdateContext) -> UR;
 }
 
 pub trait ClickHandler {
-    fn on_left_click(&mut self, point: &Point, context: &UpdateContext) -> UpdateResult;
+    fn on_left_click(&mut self, point: &Point, context: &UpdateContext) -> UR;
 
     fn is_left_click_target(&self, point: &Point, context: &UpdateContext) -> bool;
 }
 
 pub trait RenderBox {
     fn render_start_point(&self) -> Point;
+
+    fn dest(&self) -> &Rect;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::tests::support;
+    use sdl2::rect::*;
+
+    struct ConfigWrapper {
+        pub inner: ConfigAccess,
+    }
+
+    impl ConfigHolder for ConfigWrapper {
+        fn config(&self) -> &ConfigAccess {
+            &self.inner
+        }
+    }
+
+    #[test]
+    fn must_return_true_if_inside_rect() {
+        let rect = Rect::new(10, 10, 30, 30);
+        let point = Point::new(20, 20);
+        assert_eq!(is_in_rect(&point, &rect), true);
+    }
+
+    #[test]
+    fn must_return_not_if_not_inside_rect() {
+        let rect = Rect::new(10, 10, 30, 30);
+        let point = Point::new(41, 41);
+        assert_eq!(is_in_rect(&point, &rect), false);
+    }
+
+    #[test]
+    fn must_return_moved_rect() {
+        let rect = Rect::new(10, 20, 30, 40);
+        let point = Point::new(11, 11);
+        assert_eq!(move_render_point(point, &rect), Rect::new(21, 31, 30, 40));
+    }
+
+    #[test]
+    fn must_build_font_details() {
+        let config = support::build_config();
+        let wrapper = ConfigWrapper {
+            inner: config.clone(),
+        };
+        let details = build_font_details(&wrapper);
+        let c = config.read().unwrap();
+        assert_eq!(details.path, c.editor_config().font_path().to_string());
+        assert_eq!(details.size, c.editor_config().character_size());
+    }
 }

src/ui/text_character.rs

@@ -1,8 +1,8 @@
 use crate::app::{UpdateResult as UR, WindowCanvas as WC};
-use crate::config::Config;
+use crate::config::*;
 use crate::lexer::TokenType;
-use crate::renderer::managers::{FontDetails, TextDetails};
-use crate::renderer::Renderer;
+use crate::renderer::managers::*;
+use crate::renderer::*;
 use crate::ui::caret::CaretPosition;
 use crate::ui::*;
 
@@ -22,7 +22,7 @@ pub struct TextCharacter {
     source: Rect,
     dest: Rect,
     color: Color,
-    config: Arc<RwLock<Config>>,
+    config: ConfigAccess,
 }
 
 impl TextCharacter {
@@ -32,7 +32,7 @@ impl TextCharacter {
         line: usize,
         last_in_line: bool,
         color: Color,
-        config: Arc<RwLock<Config>>,
+        config: ConfigAccess,
     ) -> Self {
         Self {
             text_character,
@@ -50,14 +50,18 @@ impl TextCharacter {
         self.last_in_line
     }
 
-    pub fn dest(&self) -> &Rect {
-        &self.dest
-    }
-
     pub fn source(&self) -> &Rect {
         &self.source
     }
 
+    pub fn set_dest(&mut self, rect: &Rect) {
+        self.dest = rect.clone();
+    }
+
+    pub fn set_source(&mut self, rect: &Rect) {
+        self.source = rect.clone();
+    }
+
     pub fn color(&self) -> &Color {
         &self.color
     }
@@ -101,9 +105,9 @@ impl Render for TextCharacter {
      * Must first create targets so even if new line appear renderer will know
      * where move render starting point
      */
-    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) -> UR {
+    fn render(&self, canvas: &mut WC, renderer: &mut Renderer, parent: Parent) {
         if self.is_new_line() {
-            return UR::NoOp;
+            return;
         }
 
         let font_details = {
@@ -127,20 +131,26 @@ impl Render for TextCharacter {
             Some(parent) => move_render_point(parent.render_start_point(), self.dest()),
         };
         if let Ok(texture) = renderer.texture_manager().load_text(&mut details, &font) {
-            renderer.render_texture(canvas, &texture, &self.source, &dest);
+            canvas
+                .copy_ex(
+                    &texture,
+                    Some(self.source.clone()),
+                    Some(dest.clone()),
+                    0.0,
+                    None,
+                    false,
+                    false,
+                )
+                .unwrap();
         }
         //        let c = Color::RGB(255, 0, 0);
         //        canvas.set_draw_color(c);
         //        canvas.draw_rect(dest.clone()).unwrap();
-        UR::NoOp
     }
 
     fn prepare_ui(&mut self, renderer: &mut Renderer) {
-        let font_details = {
-            let config = renderer.config().read().unwrap();
-            let ec = config.editor_config();
-            FontDetails::new(ec.font_path().as_str(), ec.character_size().clone())
-        };
+        let font_details = build_font_details(renderer);
+
         let font = renderer
             .font_manager()
             .load(&font_details)
@@ -151,8 +161,8 @@ impl Render for TextCharacter {
             c => c,
         };
         if let Some(rect) = get_text_character_rect(c, renderer) {
-            self.source = rect.clone();
-            self.dest = rect.clone();
+            self.set_source(&rect);
+            self.set_dest(&rect);
         }
         let mut details = TextDetails {
             text: self.text_character.to_string(),
@@ -195,4 +205,311 @@ impl RenderBox for TextCharacter {
     fn render_start_point(&self) -> Point {
         self.dest.top_left()
     }
+
+    fn dest(&self) -> &Rect {
+        &self.dest
+    }
+}
+
+#[cfg(test)]
+mod test_getters {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_return_valid_is_last_in_line() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            0,
+            0,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.is_last_in_line(), true);
+    }
+
+    #[test]
+    fn must_return_true_for_is_new_line_if_new_line() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            0,
+            0,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.is_new_line(), true);
+    }
+
+    #[test]
+    fn must_return_false_for_is_new_line_if_new_line() {
+        let config = support::build_config();
+        let widget =
+            TextCharacter::new('W', 0, 0, true, Color::RGB(1, 12, 123), Arc::clone(&config));
+        assert_eq!(widget.is_new_line(), false);
+    }
+
+    #[test]
+    fn must_return_valid_position() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            1,
+            123,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.position(), 1);
+    }
+
+    #[test]
+    fn must_return_valid_line() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            1,
+            123,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.line(), 123);
+    }
+
+    #[test]
+    fn must_return_valid_text_character() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            87,
+            123,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.text_character(), '\n');
+    }
+
+    #[test]
+    fn must_return_valid_source() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            0,
+            0,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.source(), &Rect::new(0, 0, 0, 0));
+    }
+
+    #[test]
+    fn must_return_valid_dest() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            0,
+            0,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.dest(), &Rect::new(0, 0, 0, 0));
+    }
+
+    #[test]
+    fn must_return_valid_color() {
+        let config = support::build_config();
+        let widget = TextCharacter::new(
+            '\n',
+            0,
+            0,
+            true,
+            Color::RGB(1, 12, 123),
+            Arc::clone(&config),
+        );
+        assert_eq!(widget.color(), &Color::RGB(1, 12, 123));
+    }
+}
+
+#[cfg(test)]
+mod test_own_methods {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_update_position_of_new_line() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let mut current = Rect::new(10, 23, 0, 0);
+        widget.update_position(&mut current);
+        assert_eq!(current, Rect::new(0, 103, 1, 1));
+        assert_eq!(widget.dest(), &Rect::new(0, 103, 30, 40));
+        assert_eq!(widget.source(), &Rect::new(50, 60, 70, 80));
+    }
+
+    #[test]
+    fn must_update_position_of_non_new_line() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('W', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let mut current = Rect::new(10, 23, 0, 0);
+        widget.update_position(&mut current);
+        assert_eq!(current, Rect::new(80, 23, 1, 1));
+        assert_eq!(widget.dest(), &Rect::new(10, 23, 70, 80));
+        assert_eq!(widget.source(), &Rect::new(50, 60, 70, 80));
+    }
+}
+
+#[cfg(test)]
+mod test_click_handler {
+    use crate::app::*;
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn refute_when_not_click_target() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let point = Point::new(0, 0);
+        let context = UpdateContext::Nothing;
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, false);
+    }
+
+    #[test]
+    fn assert_when_click_target() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let point = Point::new(20, 30);
+        let context = UpdateContext::Nothing;
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, true);
+    }
+
+    #[test]
+    fn refute_when_not_click_target_because_parent() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let point = Point::new(20, 30);
+        let context = UpdateContext::ParentPosition(Point::new(100, 100));
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, false);
+    }
+
+    #[test]
+    fn assert_when_click_target_because_parent() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let point = Point::new(120, 130);
+        let context = UpdateContext::ParentPosition(Point::new(100, 100));
+        let result = widget.is_left_click_target(&point, &context);
+        assert_eq!(result, true);
+    }
+
+    #[test]
+    fn assert_on_click_return_move_caret() {
+        let config = support::build_config();
+        let position = 1233;
+        let line = 2893;
+        let mut widget = TextCharacter::new(
+            '\n',
+            position.clone(),
+            line.clone(),
+            true,
+            Color::RGB(0, 0, 0),
+            Arc::clone(&config),
+        );
+        let dest = Rect::new(10, 20, 30, 40);
+        widget.set_dest(&dest);
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+
+        let point = Point::new(12, 34);
+        let context = UpdateContext::ParentPosition(Point::new(678, 293));
+        let result = widget.on_left_click(&point, &context);
+        let expected = UpdateResult::MoveCaret(dest, CaretPosition::new(position, line, 0));
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_render_box {
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn must_return_top_left_point() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let result = widget.render_start_point();
+        let expected = Point::new(10, 20);
+        assert_eq!(result, expected);
+    }
+}
+
+#[cfg(test)]
+mod test_update {
+    use crate::app::*;
+    use crate::renderer::*;
+    use crate::tests::*;
+    use crate::ui::*;
+    use sdl2::pixels::*;
+    use sdl2::rect::*;
+    use std::sync::*;
+
+    #[test]
+    fn assert_do_nothing() {
+        let config = support::build_config();
+        let mut widget =
+            TextCharacter::new('\n', 0, 0, true, Color::RGB(0, 0, 0), Arc::clone(&config));
+        widget.set_dest(&Rect::new(10, 20, 30, 40));
+        widget.set_source(&Rect::new(50, 60, 70, 80));
+        let result = widget.update(
+            3234,
+            &UpdateContext::ParentPosition(Point::new(234, 234234)),
+        );
+        let expected = UpdateResult::NoOp;
+        assert_eq!(result, expected);
+    }
 }