feat: add debug mode (#72)

crates/deno_task_shell/Cargo.toml

@@ -27,6 +27,7 @@ thiserror = "1.0.63"
 pest = "2.7.12"
 pest_derive = "2.7.12"
 dirs = "5.0.1"
+pest_ascii_tree = "0.1.0"
 
 [dev-dependencies]
 parking_lot = "0.12.3"

crates/deno_task_shell/src/parser.rs

@@ -329,6 +329,11 @@ pub enum RedirectOpOutput {
 #[grammar = "grammar.pest"]
 struct ShellParser;
 
+pub fn debug_parse(input: &str) {
+  let parsed = ShellParser::parse(Rule::FILE, input);
+  pest_ascii_tree::print_ascii_tree(parsed);
+}
+
 pub fn parse(input: &str) -> Result<SequentialList> {
   let mut pairs = ShellParser::parse(Rule::FILE, input)?;
 

crates/shell/src/main.rs

@@ -5,6 +5,7 @@ use std::rc::Rc;
 use anyhow::Context;
 use clap::Parser;
 use completion::ShellCompleter;
+use deno_task_shell::parser::debug_parse;
 use deno_task_shell::{
     execute_sequential_list, AsyncCommandBehavior, ExecuteResult, ShellCommand, ShellPipeReader,
     ShellPipeWriter, ShellState,
@@ -60,6 +61,9 @@ async fn execute(text: &str, state: &mut ShellState) -> anyhow::Result<i32> {
 struct Options {
     #[clap(short, long)]
     file: Option<PathBuf>,
+
+    #[clap(short, long)]
+    debug: bool,
 }
 
 fn init_state() -> ShellState {
@@ -144,6 +148,10 @@ async fn main() -> anyhow::Result<()> {
     if let Some(file) = options.file {
         let script_text = std::fs::read_to_string(&file).unwrap();
         let mut state = init_state();
+        if options.debug {
+            debug_parse(&script_text);
+            return Ok(());
+        }
         execute(&script_text, &mut state).await?;
     } else {
         interactive().await?;