feat(builtin): fix error handling in edit-path

src/errors.rs

@@ -333,6 +333,24 @@ pub enum StateError {
     /// next directory when the stack is empty, this error is returned.
     NoNextDirectory,
 
+    /// OVERVIEW
+    /// This error occurs when the shell tries to update the PATH variable using an invalid index.
+    ///
+    /// CAUSE
+    /// - A non-existent index was provided to the 'edit-path' builtin using the 'insert' or
+    /// 'delete' subcommand.
+    ///
+    /// SOLUTION
+    /// - Check the PATH variable using the 'environment' builtin and ensure that the index provided
+    /// is valid.
+    ///
+    /// TECHNICAL DETAILS
+    /// The 'edit-path' builtin allows the user to modify the PATH variable. The PATH variable is
+    /// represented using a vector (list) of paths, which is indexed when the user provides an index
+    /// to insert or delete a path. If the user provides an index which does not exist, this error
+    /// is returned.
+    InvalidPathIndex(usize),
+
     /// OVERVIEW
     /// This error occurs when the line editor is unable to interact with the terminal.
     ///
@@ -616,6 +634,9 @@ impl Display for StateError {
             }
             NoPreviousDirectory => write!(f, "No previous directory"),
             NoNextDirectory => write!(f, "No next directory"),
+            InvalidPathIndex(index) => {
+                write!(f, "Path index {} is invalid", index)
+            }
             UnsupportedTerminal => write!(f, "Terminal is not supported"),
         }
     }

src/eval/dispatcher.rs

@@ -94,7 +94,7 @@ impl Dispatcher {
             command.run(shell, command_args)
         } else {
             // If the command is not in the Dispatcher, try to run it as an executable from the PATH
-            let path = Path::try_resolve_executable(command_name, &shell.environment.PATH);
+            let path = Path::try_resolve_executable(command_name, shell.environment.PATH());
             if let Ok(path) = path {
                 // Check if the file is executable (has the executable bit set)
                 if let Ok(metadata) = fs_err::metadata(path.path()) {

src/exec/builtins/functions.rs

@@ -42,7 +42,7 @@ pub fn exit(_shell: &mut ShellState, args: Vec<&str>) -> Result<()> {
 
 pub fn working_directory(shell: &mut ShellState, args: Vec<&str>) -> Result<()> {
     clap_handle!(WorkingDirectoryArgs::try_parse_from(args));
-    println!("{}", shell.environment.CWD);
+    println!("{}", shell.CWD());
     Ok(())
 }
 
@@ -60,9 +60,7 @@ pub fn change_directory(shell: &mut ShellState, args: Vec<&str>) -> Result<()> {
 pub fn list_directory(shell: &mut ShellState, args: Vec<&str>) -> Result<()> {
     let arguments = clap_handle!(ListDirectoryArgs::try_parse_from(&args));
     let show_hidden = arguments.show_hidden;
-    let path_to_read = arguments
-        .path
-        .unwrap_or(shell.environment.CWD.path().to_path_buf());
+    let path_to_read = arguments.path.unwrap_or(shell.CWD().path().to_path_buf());
 
     let read_dir_result =
         fs_err::read_dir(&path_to_read).replace_err(|| file_err!(UnknownPath: path_to_read))?;
@@ -218,9 +216,9 @@ pub fn environment_variable(shell: &mut ShellState, args: Vec<&str>) -> Result<(
     match arguments.variable {
         USER => println!("{}", shell.environment.USER),
         HOME => println!("{}", shell.environment.HOME.display()),
-        CWD => println!("{}", shell.environment.CWD),
+        CWD => println!("{}", shell.CWD()),
         PATH => {
-            for (i, path) in shell.environment.PATH.iter().enumerate() {
+            for (i, path) in shell.environment.PATH().iter().enumerate() {
                 println!("[{i}]: {path}");
             }
         }
@@ -230,26 +228,19 @@ pub fn environment_variable(shell: &mut ShellState, args: Vec<&str>) -> Result<(
 }
 
 pub fn edit_path(shell: &mut ShellState, args: Vec<&str>) -> Result<()> {
-    // TODO: Needs to update the real PATH
     let arguments = clap_handle!(EditPathArgs::try_parse_from(args));
     use EditPathSubcommand::*;
     match arguments.subcommand {
         Append(AppendPathCommand { path }) => shell
             .environment
-            .PATH
-            .push_front(Path::try_from_path(&path, Some(&shell.environment.HOME))?),
+            .PATH_append(Path::try_from_path(&path, Some(&shell.environment.HOME))?),
         Prepend(PrependPathCommand { path }) => shell
             .environment
-            .PATH
-            .push_front(Path::try_from_path(&path, Some(&shell.environment.HOME))?),
-        Insert(InsertPathCommand { index, path }) => shell.environment.PATH.insert(
+            .PATH_prepend(Path::try_from_path(&path, Some(&shell.environment.HOME))?),
+        Insert(InsertPathCommand { index, path }) => shell.environment.PATH_insert(
             index,
             Path::try_from_path(&path, Some(&shell.environment.HOME))?,
         ),
-        Delete(DeletePathCommand { index }) => {
-            shell.environment.PATH.remove(index);
-        }
+        Delete(DeletePathCommand { index }) => shell.environment.PATH_delete(index),
     }
-
-    Ok(())
 }

src/state/environment.rs

@@ -63,10 +63,11 @@ bitflags! {
 pub struct Environment {
     pub USER: String,
     pub HOME: PathBuf,
-    pub CWD: Path,
+    CWD: Path,
     // * PATH is not to be confused with the WORKING_DIRECTORY. PATH is a list of directories which
     // * the shell will search for executables in. WORKING_DIRECTORY is the current directory the user is in.
-    pub PATH: VecDeque<Path>,
+    PATH: VecDeque<Path>,
+    // ? Should these be `ShellState` fields instead?
     backward_directories: VecDeque<Path>,
     forward_directories: VecDeque<Path>,
     #[allow(dead_code)]
@@ -157,6 +158,46 @@ impl Environment {
             Err(state_err!(NoNextDirectory))
         }
     }
+
+    /// Appends a path to the PATH variable
+    pub fn PATH_append(&mut self, path: Path) -> Result<()> {
+        self.PATH.push_back(path);
+        self.update_process_env_vars(EnvVariables::PATH)
+    }
+
+    /// Prepends a path to the PATH variable
+    pub fn PATH_prepend(&mut self, path: Path) -> Result<()> {
+        self.PATH.push_front(path);
+        self.update_process_env_vars(EnvVariables::PATH)
+    }
+
+    /// Inserts a path at the specified index in the PATH variable
+    pub fn PATH_insert(&mut self, index: usize, path: Path) -> Result<()> {
+        if index > self.PATH.len() {
+            return Err(state_err!(InvalidPathIndex: index));
+        }
+
+        self.PATH.insert(index, path);
+        self.update_process_env_vars(EnvVariables::PATH)
+    }
+
+    /// Deletes the path at the specified index in the PATH variable
+    pub fn PATH_delete(&mut self, index: usize) -> Result<()> {
+        self.PATH
+            .remove(index)
+            .replace_err(|| state_err!(InvalidPathIndex: index))?;
+        self.update_process_env_vars(EnvVariables::PATH)
+    }
+
+    /// Getter for the current working directory
+    pub fn CWD(&self) -> &Path {
+        &self.CWD
+    }
+
+    /// Getter for the PATH
+    pub fn PATH(&self) -> &VecDeque<Path> {
+        &self.PATH
+    }
 }
 
 /// Gets the environment variables from the parent process during shell initialization

src/state/shell.rs

@@ -4,6 +4,7 @@ use crossterm::style::Stylize;
 
 use super::config::Configuration;
 use super::environment::Environment;
+use super::Path;
 use crate::errors::Result;
 
 /// Represents the shell state and provides methods for interacting with it
@@ -32,7 +33,7 @@ impl ShellState {
         let user = self.environment.USER.clone();
         let home = &self.environment.HOME;
         let truncation = self.config.truncation;
-        let cwd = self.environment.CWD.collapse(home, truncation);
+        let cwd = self.CWD().collapse(home, truncation);
         let prompt_delimiter = match self.config.multiline_prompt {
             true => "\n",
             false => " ",
@@ -53,4 +54,10 @@ impl ShellState {
             prompt_tick
         )
     }
+
+    /// Convenience getter for the current working directory
+    #[allow(non_snake_case)]
+    pub fn CWD(&self) -> &Path {
+        self.environment.CWD()
+    }
 }