diff --git a/.gitignore b/.gitignore
index 6892901..a270cd4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ log
 .codecov
 cobertura.xml
 cov
+tarpaulin-report.html
diff --git a/rider-config/src/config.rs b/rider-config/src/config.rs
index 0a8b1ef..56fe9b8 100644
--- a/rider-config/src/config.rs
+++ b/rider-config/src/config.rs
@@ -28,6 +28,7 @@ impl Config {
         extensions_mapping.insert(".".to_string(), Language::PlainText);
         extensions_mapping.insert("txt".to_string(), Language::PlainText);
         extensions_mapping.insert("rs".to_string(), Language::Rust);
+        extensions_mapping.insert("toml".to_string(), Language::Toml);
 
         Self {
             width: 1024,
@@ -130,16 +131,24 @@ mod tests {
         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()];
+            let mut expected: Vec<String> = vec![
+                ".".to_string(),
+                "txt".to_string(),
+                "rs".to_string(),
+                "toml".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];
+            let mut expected: Vec<Language> = vec![
+                Language::PlainText,
+                Language::PlainText,
+                Language::Rust,
+                Language::Toml,
+            ];
             keys.sort();
             expected.sort();
             assert_eq!(keys, expected);
@@ -234,7 +243,12 @@ mod test_getters {
             .map(|s| s.to_owned())
             .collect();
         result.sort();
-        let mut expected: Vec<String> = vec!["rs".to_string(), "txt".to_string(), ".".to_string()];
+        let mut expected: Vec<String> = vec![
+            "rs".to_string(),
+            "txt".to_string(),
+            ".".to_string(),
+            "toml".to_string(),
+        ];
         expected.sort();
         assert_eq!(result, expected);
     }
diff --git a/rider-editor/src/app/app_state.rs b/rider-editor/src/app/app_state.rs
index 23b0f56..d28d74d 100644
--- a/rider-editor/src/app/app_state.rs
+++ b/rider-editor/src/app/app_state.rs
@@ -1,7 +1,6 @@
 use crate::app::application::Application;
 use crate::app::UpdateResult;
 use crate::renderer::renderer::Renderer;
-use crate::renderer::CanvasRenderer;
 use crate::ui::*;
 use rider_config::*;
 use sdl2::rect::Point;
@@ -35,21 +34,22 @@ impl AppState {
     }
 
     #[cfg_attr(tarpaulin, skip)]
-    pub fn open_file(&mut self, file_path: String, renderer: &mut CanvasRenderer) {
-        if let Ok(buffer) = read_to_string(&file_path) {
-            let mut file = EditorFile::new(file_path.clone(), buffer, self.config.clone());
-            file.prepare_ui(renderer);
-            match self.file_editor.open_file(file) {
-                Some(old) => self.files.push(old),
-                _ => (),
-            }
-        } else {
-            eprintln!("Failed to open file: {}", file_path);
-        };
+    pub fn open_file<R>(&mut self, file_path: String, renderer: &mut R) -> Result<(), String>
+    where
+        R: Renderer + CharacterSizeManager + ConfigHolder,
+    {
+        let buffer = read_to_string(&file_path)
+            .map_err(|file_path| format!("Failed to open file: {}", file_path))?;
+        let mut file = EditorFile::new(file_path.clone(), buffer, self.config.clone());
+        file.prepare_ui(renderer);
+        match self.file_editor.open_file(file) {
+            Some(old) => self.files.push(old),
+            _ => (),
+        }
+        Ok(())
     }
 
     pub fn save_file(&self) -> Result<(), String> {
-        println!("Saving file...");
         let editor_file = match self.file_editor.file() {
             Some(f) => f,
             _ => Err("No buffer found".to_string())?,
@@ -69,7 +69,6 @@ impl AppState {
     where
         R: Renderer + CharacterSizeManager,
     {
-        println!("Open Settings...");
         match self.modal {
             None => {
                 let mut settings = Settings::new(self.config.clone());
@@ -255,7 +254,6 @@ impl ConfigHolder for AppState {
 mod tests {
     use super::*;
     use crate::tests::support;
-    //    use crate::ui::modal::open_file;
     use std::sync::Arc;
 
     #[test]
@@ -294,4 +292,94 @@ mod tests {
             old_scroll
         );
     }
+
+    #[test]
+    fn must_fail_save_file_when_none_is_open() {
+        let config = support::build_config();
+        let state = AppState::new(Arc::clone(&config));
+        let result = state.save_file();
+        assert_eq!(result, Err(format!("No buffer found")));
+    }
+
+    #[test]
+    fn must_succeed_save_file_when_file_is_open() {
+        assert_eq!(std::fs::create_dir_all("/tmp").is_ok(), true);
+        assert_eq!(
+            std::fs::write(
+                "/tmp/must_succeed_save_file_when_file_is_open.md",
+                "Foo bar"
+            )
+            .is_ok(),
+            true
+        );
+
+        let config = support::build_config();
+        let mut renderer = support::SimpleRendererMock::new(config.clone());
+        let mut state = AppState::new(Arc::clone(&config));
+        let result = state.open_file(
+            format!("/tmp/must_succeed_save_file_when_file_is_open.md"),
+            &mut renderer,
+        );
+        assert_eq!(result, Ok(()));
+        let result = state.save_file();
+        assert_eq!(result, Ok(()));
+    }
+
+    #[test]
+    fn must_succeed_save_file_when_file_does_not_exists() {
+        assert_eq!(std::fs::create_dir_all("/tmp").is_ok(), true);
+        assert_eq!(
+            std::fs::write(
+                "/tmp/must_succeed_save_file_when_file_does_not_exists.md",
+                "Foo bar"
+            )
+            .is_ok(),
+            true
+        );
+
+        let config = support::build_config();
+        let mut renderer = support::SimpleRendererMock::new(config.clone());
+        let mut state = AppState::new(Arc::clone(&config));
+        let result = state.open_file(
+            format!("/tmp/must_succeed_save_file_when_file_does_not_exists.md"),
+            &mut renderer,
+        );
+        assert_eq!(result, Ok(()));
+        let result = state.save_file();
+        assert_eq!(result, Ok(()));
+    }
+
+    #[test]
+    fn must_close_modal_when_no_modal_is_open() {
+        let config = support::build_config();
+        let mut state = AppState::new(Arc::clone(&config));
+        assert_eq!(state.close_modal(), Ok(()));
+    }
+
+    #[test]
+    fn must_close_modal_when_some_modal_is_open() {
+        let config = support::build_config();
+        let mut state = AppState::new(Arc::clone(&config));
+        let modal = OpenFile::new("/".to_owned(), 100, 100, Arc::clone(&config));
+        state.set_open_file_modal(Some(modal));
+        assert_eq!(state.close_modal(), Ok(()));
+    }
+
+    #[test]
+    fn open_settings_when_there_is_no_other_modal() {
+        let config = support::build_config();
+        let mut renderer = support::SimpleRendererMock::new(config.clone());
+        let mut state = AppState::new(Arc::clone(&config));
+        assert_eq!(state.open_settings(&mut renderer), Ok(()));
+    }
+
+    #[test]
+    fn open_settings_when_other_modal_is_open() {
+        let config = support::build_config();
+        let mut renderer = support::SimpleRendererMock::new(config.clone());
+        let mut state = AppState::new(Arc::clone(&config));
+        let modal = OpenFile::new("/".to_owned(), 100, 100, Arc::clone(&config));
+        state.set_open_file_modal(Some(modal));
+        assert_eq!(state.open_settings(&mut renderer), Ok(()));
+    }
 }
diff --git a/rider-editor/src/app/application.rs b/rider-editor/src/app/application.rs
index f384f96..05b8bde 100644
--- a/rider-editor/src/app/application.rs
+++ b/rider-editor/src/app/application.rs
@@ -117,10 +117,10 @@ impl Application {
         self.clear();
     }
 
-    pub fn run(&mut self) {
-        let mut timer: TimerSubsystem = self.sdl_context.timer().unwrap();
-        let mut event_pump = self.sdl_context.event_pump().unwrap();
-        let font_context = sdl2::ttf::init().unwrap();
+    pub fn run(&mut self) -> Result<(), String> {
+        let mut timer: TimerSubsystem = self.sdl_context.timer()?;
+        let mut event_pump = self.sdl_context.event_pump()?;
+        let font_context = sdl2::ttf::init().map_err(|e| format!("{:?}", e))?;
         let texture_creator = self.canvas.texture_creator();
         let sleep_time = Duration::new(0, 1_000_000_000u32 / 60);
         let mut app_state = AppState::new(Arc::clone(&self.config));
@@ -159,14 +159,12 @@ impl Application {
                     UpdateResult::Input(text) => app_state
                         .file_editor_mut()
                         .insert_text(text.clone(), &mut renderer),
-                    UpdateResult::InsertNewLine => app_state
-                        .file_editor_mut()
-                        .insert_new_line(&mut renderer)
-                        .unwrap_or_else(|e| eprintln!("Failed to delete line {:?}", e)),
+                    UpdateResult::InsertNewLine => {
+                        app_state.file_editor_mut().insert_new_line(&mut renderer)?
+                    }
                     UpdateResult::DeleteLine => app_state
                         .file_editor_mut()
-                        .delete_current_line(&mut renderer)
-                        .unwrap_or_else(|e| eprintln!("Failed to delete line {:?}", e)),
+                        .delete_current_line(&mut renderer)?,
                     UpdateResult::MoveCaretLeft => {
                         app_state.file_editor_mut().move_caret(MoveDirection::Left);
                     }
@@ -193,10 +191,10 @@ impl Application {
                                 c.set_height(*height as u32);
                             }
                         })
-                        .unwrap_or_else(|_| println!("Failed to update window size")),
+                        .map_err(|_| format!("Failed to update window size"))?,
                     UpdateResult::RefreshFsTree => unimplemented!(),
                     UpdateResult::OpenFile(file_path) => {
-                        app_state.open_file(file_path.clone(), &mut renderer);
+                        app_state.open_file(file_path.clone(), &mut renderer)?;
                     }
                     UpdateResult::OpenDirectory(dir_path) => {
                         app_state.open_directory(dir_path.clone(), &mut renderer);
@@ -212,15 +210,9 @@ impl Application {
                     UpdateResult::MouseDragStart(_point) => (),
                     UpdateResult::MouseDragStop(_point) => (),
                     UpdateResult::FileDropped(_path) => (),
-                    UpdateResult::SaveCurrentFile => app_state
-                        .save_file()
-                        .unwrap_or_else(|e| eprintln!("Failed to save {:?}", e)),
-                    UpdateResult::OpenSettings => app_state
-                        .open_settings(&mut renderer)
-                        .unwrap_or_else(|e| eprintln!("Failed to open settings {:?}", e)),
-                    UpdateResult::CloseModal => app_state
-                        .close_modal()
-                        .unwrap_or_else(|e| eprintln!("Failed to close modal {:?}", e)),
+                    UpdateResult::SaveCurrentFile => app_state.save_file()?,
+                    UpdateResult::OpenSettings => app_state.open_settings(&mut renderer)?,
+                    UpdateResult::CloseModal => app_state.close_modal()?,
                 }
             }
             self.tasks = new_tasks;
@@ -236,6 +228,8 @@ impl Application {
                 sleep(sleep_time);
             }
         }
+
+        Ok(())
     }
 
     pub fn open_file(&mut self, file_path: String) {
diff --git a/rider-editor/src/main.rs b/rider-editor/src/main.rs
index 0f877fd..21dc7f1 100644
--- a/rider-editor/src/main.rs
+++ b/rider-editor/src/main.rs
@@ -47,11 +47,11 @@ fn init_logger(directories: &Directories) {
 }
 
 #[cfg_attr(tarpaulin, skip)]
-fn main() {
+fn main() -> Result<(), String> {
     let directories = Directories::new(None, None);
     let mut app = Application::new();
     app.init();
     init_logger(&directories);
     app.open_file("./test_files/test.rs".to_string());
-    app.run();
+    app.run()
 }
diff --git a/rider-lexers/src/lib.rs b/rider-lexers/src/lib.rs
index 72bc94a..37840d1 100644
--- a/rider-lexers/src/lib.rs
+++ b/rider-lexers/src/lib.rs
@@ -1,15 +1,140 @@
 extern crate log;
+//#[macro_use]
+extern crate plex;
 extern crate simplelog;
 
 use std::ops::Deref;
 
 pub mod plain;
 pub mod rust_lang;
+pub mod toml;
+
+#[macro_export]
+macro_rules! lexer_whitespace {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Whitespace {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_keyword {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Keyword {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_string {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::String {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_identifier {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Identifier {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_literal {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Literal {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_comment {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Comment {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_operator {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Operator {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+#[macro_export]
+macro_rules! lexer_separator {
+    ($provider: expr) => {{
+        let text = $provider.text();
+        let line = $provider.line();
+        let character = $provider.character();
+        let start = $provider.start();
+        let end = $provider.end(&text);
+
+        TokenType::Separator {
+            token: Token::new(text, line, character, start, end),
+        }
+    }};
+}
+
+pub trait TokenBuilder {
+    fn text(&self) -> String;
+    fn line(&self) -> usize;
+    fn character(&self) -> usize;
+    fn start(&self) -> usize;
+    fn end(&self, current_text: &String) -> usize;
+}
 
 #[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Ord, Eq)]
 pub enum Language {
     PlainText,
     Rust,
+    Toml,
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -92,7 +217,7 @@ pub struct Span {
     pub hi: usize,
 }
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Clone, PartialEq)]
 pub struct Token {
     line: usize,
     character: usize,
@@ -101,6 +226,22 @@ pub struct Token {
     text: String,
 }
 
+impl std::fmt::Debug for Token {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        self.text.fmt(f)?;
+        f.write_str(" { ")?;
+        f.write_str("line ")?;
+        self.line.fmt(f)?;
+        f.write_str(" character ")?;
+        self.character.fmt(f)?;
+        f.write_str(" start ")?;
+        self.start.fmt(f)?;
+        f.write_str(" end ")?;
+        self.end.fmt(f)?;
+        f.write_str(" }")
+    }
+}
+
 impl Token {
     pub fn new(text: String, line: usize, character: usize, start: usize, end: usize) -> Self {
         Self {
@@ -153,6 +294,7 @@ pub fn parse(text: String, language: Language) -> Vec<TokenType> {
             //            .inspect(|tok| warn!("tok: {:?}", tok))
             .map(|t| t.0)
             .collect(),
+        Language::Toml => toml::lexer::Lexer::new(text).tokenize(),
     }
 }
 
diff --git a/rider-lexers/src/rust_lang.rs b/rider-lexers/src/rust_lang.rs
index 704d9db..4e7b5fd 100644
--- a/rider-lexers/src/rust_lang.rs
+++ b/rider-lexers/src/rust_lang.rs
@@ -97,9 +97,10 @@ pub mod lexer {
 
 #[cfg(test)]
 mod tests {
-    use super::*;
     use crate::{Token, TokenType};
 
+    use super::*;
+
     #[test]
     fn must_parse_simple_text() {
         let code = "foo";
diff --git a/rider-lexers/src/toml.rs b/rider-lexers/src/toml.rs
new file mode 100644
index 0000000..9b78a59
--- /dev/null
+++ b/rider-lexers/src/toml.rs
@@ -0,0 +1,284 @@
+pub mod lexer {
+    use crate::{Token, TokenType};
+    use std::ops::{Deref, DerefMut};
+
+    use crate::*;
+
+    #[derive(Debug)]
+    pub struct Buffer(String);
+
+    impl Buffer {
+        pub fn new() -> Self {
+            Self(String::new())
+        }
+
+        pub fn is_string(&self) -> bool {
+            self.0.starts_with('\'') || self.0.starts_with('"')
+        }
+
+        pub fn is_escaped(&self) -> bool {
+            self.0.ends_with('\\')
+        }
+
+        pub fn is_string_beginning(&self, c: char) -> bool {
+            self.is_string() && self.0.starts_with(c)
+        }
+
+        pub fn is_white(&self) -> bool {
+            self.0.as_str() == " "
+                || self.0.as_str() == "\t"
+                || self.0.as_str() == "\n"
+                || self.0.as_str() == "\r"
+        }
+    }
+
+    impl Deref for Buffer {
+        type Target = String;
+
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl DerefMut for Buffer {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    pub struct Lexer {
+        content: String,
+        buffer: Buffer,
+        line: usize,
+        character: usize,
+        start: usize,
+    }
+
+    impl Lexer {
+        pub fn new(content: String) -> Self {
+            Self {
+                content,
+                line: 0,
+                character: 0,
+                start: 0,
+                buffer: Buffer::new(),
+            }
+        }
+
+        pub fn tokenize(&mut self) -> Vec<TokenType> {
+            let mut tokens = vec![];
+            let content = self.content.clone();
+            for c in content.chars() {
+                match c {
+                    ' ' | '\n' if self.non_special() => {
+                        self.push_non_empty(&mut tokens);
+                        self.append_and_push(c, &mut tokens, |b| lexer_whitespace!(b))
+                    }
+                    '[' | ']' | '{' | '}' if self.non_special() => {
+                        self.push_non_empty(&mut tokens);
+                        self.append_and_push(c, &mut tokens, |b| lexer_separator!(b))
+                    }
+                    '=' if self.non_special() => {
+                        self.push_non_empty(&mut tokens);
+                        self.append_and_push(c, &mut tokens, |b| lexer_operator!(b))
+                    }
+                    '"' | '\'' if self.is_string_beginning(c) => {
+                        self.append_and_push(c, &mut tokens, |b| lexer_string!(b))
+                    }
+                    _ => {
+                        self.buffer.push(c);
+                    }
+                }
+            }
+            if !self.is_empty() {
+                tokens.push(lexer_identifier!(self));
+                self.clear();
+            }
+            tokens
+        }
+
+        fn append_and_push<F>(&mut self, c: char, tokens: &mut Vec<TokenType>, builder: F)
+        where
+            F: Fn(&Lexer) -> TokenType,
+        {
+            self.buffer.push(c);
+            tokens.push(builder(&self));
+            self.clear();
+        }
+
+        fn push_non_empty(&mut self, tokens: &mut Vec<TokenType>) {
+            if self.is_empty() {
+                return;
+            }
+            tokens.push(self.match_token());
+        }
+
+        fn non_special(&self) -> bool {
+            !self.buffer.is_string()
+        }
+
+        fn match_token(&mut self) -> TokenType {
+            let token = if self.buffer.is_string() {
+                lexer_string!(self)
+            } else if self.buffer.is_white() {
+                lexer_whitespace!(self)
+            } else {
+                lexer_identifier!(self)
+            };
+            self.clear();
+            token
+        }
+
+        fn clear(&mut self) {
+            if self.buffer.contains('\n') {
+                self.line += self.buffer.lines().count();
+                self.character +=
+                    self.buffer.len() - self.buffer.rfind('\n').unwrap_or(self.buffer.len());
+                self.start += self.buffer.len();
+            } else {
+                self.character += self.buffer.len();
+                self.start += self.buffer.len();
+            }
+            self.buffer.clear();
+        }
+    }
+
+    impl Deref for Lexer {
+        type Target = Buffer;
+
+        fn deref(&self) -> &Self::Target {
+            &self.buffer
+        }
+    }
+
+    impl TokenBuilder for Lexer {
+        fn text(&self) -> String {
+            self.buffer.to_string()
+        }
+
+        fn line(&self) -> usize {
+            self.line
+        }
+
+        fn character(&self) -> usize {
+            self.character
+        }
+
+        fn start(&self) -> usize {
+            self.start
+        }
+
+        fn end(&self, text: &String) -> usize {
+            self.start + text.len()
+        }
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        struct BuilderMock {
+            line: usize,
+            character: usize,
+            start: usize,
+            text: String,
+        }
+
+        impl TokenBuilder for BuilderMock {
+            fn text(&self) -> String {
+                self.text.clone()
+            }
+
+            fn line(&self) -> usize {
+                self.line
+            }
+
+            fn character(&self) -> usize {
+                self.character
+            }
+
+            fn start(&self) -> usize {
+                self.start
+            }
+
+            fn end(&self, current_text: &String) -> usize {
+                self.start + current_text.len()
+            }
+        }
+
+        macro_rules! builder {
+            ($text: expr, $line: expr, $character: expr, $start: expr) => {
+                BuilderMock {
+                    line: $line,
+                    character: $character,
+                    start: $start,
+                    text: $text.to_owned(),
+                }
+            };
+        }
+
+        #[test]
+        fn parse_empty() {
+            let code = "".to_owned();
+            let mut lexer = Lexer::new(code);
+            let result = lexer.tokenize();
+            let expected = vec![];
+            assert_eq!(result, expected)
+        }
+
+        #[test]
+        fn parse_section() {
+            let code = "[package]".to_owned();
+            let mut lexer = Lexer::new(code);
+            let result = lexer.tokenize();
+            let expected = vec![
+                lexer_separator!(builder!("[", 0, 0, 0)),
+                lexer_identifier!(builder!("package", 0, 1, 1)),
+                lexer_separator!(builder!("]", 0, 8, 8)),
+            ];
+            assert_eq!(result, expected)
+        }
+
+        #[test]
+        fn parse_package() {
+            let code = "redis = \"*\"".to_owned();
+            let mut lexer = Lexer::new(code);
+            let result = lexer.tokenize();
+            let expected = vec![
+                lexer_identifier!(builder!("redis", 0, 0, 0)),
+                lexer_whitespace!(builder!(" ", 0, 5, 5)),
+                lexer_operator!(builder!("=", 0, 6, 6)),
+                lexer_whitespace!(builder!(" ", 0, 7, 7)),
+                lexer_string!(builder!("\"*\"", 0, 8, 8)),
+            ];
+            assert_eq!(result, expected)
+        }
+
+        #[test]
+        fn parse_complex_package() {
+            let code = "redis = { version = \"*\" }".to_owned();
+            let mut lexer = Lexer::new(code);
+            let result = lexer.tokenize();
+            let expected = vec![
+                lexer_identifier!(builder!("redis", 0, 0, 0)),
+                lexer_whitespace!(builder!(" ", 0, 5, 5)),
+                lexer_operator!(builder!("=", 0, 6, 6)),
+                lexer_whitespace!(builder!(" ", 0, 7, 7)),
+                lexer_separator!(builder!("{", 0, 8, 8)),
+                lexer_whitespace!(builder!(" ", 0, 9, 9)),
+                lexer_identifier!(builder!("version", 0, 10, 10)),
+                lexer_whitespace!(builder!(" ", 0, 17, 17)),
+                lexer_operator!(builder!("=", 0, 18, 18)),
+                lexer_whitespace!(builder!(" ", 0, 19, 19)),
+                lexer_string!(builder!("\"*\"", 0, 20, 20)),
+                lexer_whitespace!(builder!(" ", 0, 23, 23)),
+                lexer_separator!(builder!("}", 0, 24, 24)),
+            ];
+            assert_eq!(result, expected)
+        }
+    }
+}
+
+mod compiler {
+    //    pub struct Compiler {}
+}