feat: implement alias (#101)

crates/deno_task_shell/src/shell/execute.rs

@@ -643,8 +643,19 @@ fn execute_command_args(
   let command_name = if args.is_empty() {
     String::new()
   } else {
+    // check if the command name is in the alias hashmap
+    if let Some(value) = state.alias_map().get(&args[0]) {
+      args.remove(0);
+      args = value
+        .iter()
+        .chain(args.iter())
+        .cloned()
+        .collect::<Vec<String>>();
+    }
+
     args.remove(0)
   };
+
   if state.token().is_cancelled() {
     Box::pin(future::ready(ExecuteResult::for_cancellation()))
   } else if let Some(stripped_name) = command_name.strip_prefix('!') {

crates/deno_task_shell/src/shell/types.rs

@@ -27,8 +27,12 @@ pub struct ShellState {
   /// Variables that should be evaluated within the shell and
   /// not passed down to any sub commands.
   shell_vars: HashMap<String, String>,
+  /// The current working directory of the shell
   cwd: PathBuf,
+  /// The commands that are available in the shell
   commands: Rc<HashMap<String, Rc<dyn ShellCommand>>>,
+  /// A map of aliases for commands (e.g. `ll=ls -al`)
+  alias: HashMap<String, Vec<String>>,
   /// Token to cancel execution.
   token: CancellationToken,
   /// Git repository handling.
@@ -51,6 +55,7 @@ impl ShellState {
     let mut result = Self {
       env_vars: Default::default(),
       shell_vars: Default::default(),
+      alias: Default::default(),
       cwd: PathBuf::new(),
       commands: Rc::new(commands),
       token: CancellationToken::default(),
@@ -72,6 +77,10 @@ impl ShellState {
     &self.cwd
   }
 
+  pub fn alias_map(&self) -> &HashMap<String, Vec<String>> {
+    &self.alias
+  }
+
   pub fn git_repository(&self) -> bool {
     self.git_repository
   }
@@ -131,7 +140,7 @@ impl ShellState {
     }
   }
 
-  // TODO: set_cwd() is being called twice
+  /// Set the current working directory of this shell
   pub fn set_cwd(&mut self, cwd: &Path) {
     self.cwd = cwd.to_path_buf();
     // $PWD holds the current working directory, so we keep cwd and $PWD in sync
@@ -204,6 +213,15 @@ impl ShellState {
         self.set_cwd(new_dir);
         self.last_command_cd = true;
       }
+      EnvChange::AliasCommand(alias, cmd) => {
+        self.alias.insert(
+          alias.clone(),
+          cmd.split_whitespace().map(ToString::to_string).collect(),
+        );
+      }
+      EnvChange::UnAliasCommand(alias) => {
+        self.alias.remove(alias);
+      }
     }
   }
 
@@ -264,12 +282,17 @@ impl ShellState {
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum EnvChange {
-  // `export ENV_VAR=VALUE`
+  /// `export ENV_VAR=VALUE`
   SetEnvVar(String, String),
-  // `ENV_VAR=VALUE`
+  /// `ENV_VAR=VALUE`
   SetShellVar(String, String),
-  // `unset ENV_VAR`
+  /// Create an alias for a command (e.g. ll=ls -al)
+  AliasCommand(String, String),
+  /// Remove an alias
+  UnAliasCommand(String),
+  /// `unset ENV_VAR`
   UnsetVar(String),
+  /// Set the current working directory to the new Path
   Cd(PathBuf),
 }
 

crates/shell/src/commands.rs

@@ -1,11 +1,48 @@
 use std::ffi::OsString;
 
-use deno_task_shell::{ExecuteResult, ShellCommand, ShellCommandContext};
+use deno_task_shell::{EnvChange, ExecuteResult, ShellCommand, ShellCommandContext};
 use futures::future::LocalBoxFuture;
 
 use uu_ls::uumain as uu_ls;
 pub struct LsCommand;
 
+pub struct AliasCommand;
+
+pub struct UnAliasCommand;
+
+impl ShellCommand for AliasCommand {
+    fn execute(&self, context: ShellCommandContext) -> LocalBoxFuture<'static, ExecuteResult> {
+        if context.args.len() != 1 {
+            return Box::pin(futures::future::ready(ExecuteResult::from_exit_code(1)));
+        }
+
+        // parse the args
+        let env_change = if let Some((alias, cmd)) = context.args[0].split_once('=') {
+            vec![EnvChange::AliasCommand(alias.into(), cmd.into())]
+        } else {
+            return Box::pin(futures::future::ready(ExecuteResult::from_exit_code(1)));
+        };
+
+        let result = ExecuteResult::Continue(0, env_change, Vec::default());
+        Box::pin(futures::future::ready(result))
+    }
+}
+
+impl ShellCommand for UnAliasCommand {
+    fn execute(&self, context: ShellCommandContext) -> LocalBoxFuture<'static, ExecuteResult> {
+        if context.args.len() != 1 {
+            return Box::pin(futures::future::ready(ExecuteResult::from_exit_code(1)));
+        }
+
+        let result = ExecuteResult::Continue(
+            0,
+            vec![EnvChange::UnAliasCommand(context.args[0].clone())],
+            Vec::default(),
+        );
+        Box::pin(futures::future::ready(result))
+    }
+}
+
 impl ShellCommand for LsCommand {
     fn execute(&self, context: ShellCommandContext) -> LocalBoxFuture<'static, ExecuteResult> {
         let result = execute_ls(context);

crates/shell/src/main.rs

@@ -17,10 +17,20 @@ mod completion;
 mod helper;
 
 fn commands() -> HashMap<String, Rc<dyn ShellCommand>> {
-    HashMap::from([(
-        "ls".to_string(),
-        Rc::new(commands::LsCommand) as Rc<dyn ShellCommand>,
-    )])
+    HashMap::from([
+        (
+            "ls".to_string(),
+            Rc::new(commands::LsCommand) as Rc<dyn ShellCommand>,
+        ),
+        (
+            "alias".to_string(),
+            Rc::new(commands::AliasCommand) as Rc<dyn ShellCommand>,
+        ),
+        (
+            "unalias".to_string(),
+            Rc::new(commands::AliasCommand) as Rc<dyn ShellCommand>,
+        ),
+    ])
 }
 
 async fn execute(text: &str, state: &mut ShellState) -> anyhow::Result<i32> {
@@ -48,8 +58,8 @@ async fn execute(text: &str, state: &mut ShellState) -> anyhow::Result<i32> {
 
     match result {
         ExecuteResult::Continue(exit_code, changes, _) => {
-            state.apply_changes(&changes);
             // set CWD to the last command's CWD
+            state.apply_changes(&changes);
             std::env::set_current_dir(state.cwd()).context("Failed to set CWD")?;
             Ok(exit_code)
         }