From 61b70943b1caef016ae986c9169dd46dce78783e Mon Sep 17 00:00:00 2001
From: Jake Sarjeant <jake@sarjeant.me>
Date: Tue, 18 Jul 2023 13:24:52 +0200
Subject: [PATCH] feat(cli): add option to select JS runtime other than node

---
 cli/src/generate/mod.rs      | 23 +++++++++++++----------
 cli/src/main.rs              | 10 ++++++++++
 cli/src/tests/corpus_test.rs |  2 +-
 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/cli/src/generate/mod.rs b/cli/src/generate/mod.rs
index 4e1cac63..3c0aeda1 100644
--- a/cli/src/generate/mod.rs
+++ b/cli/src/generate/mod.rs
@@ -21,10 +21,10 @@ use anyhow::{anyhow, Context, Result};
 use lazy_static::lazy_static;
 use regex::{Regex, RegexBuilder};
 use semver::Version;
-use std::fs;
 use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
+use std::{env, fs};
 
 lazy_static! {
     static ref JSON_COMMENT_REGEX: Regex = RegexBuilder::new("^\\s*//.*")
@@ -44,16 +44,17 @@ pub fn generate_parser_in_directory(
     abi_version: usize,
     generate_bindings: bool,
     report_symbol_name: Option<&str>,
+    js_runtime: Option<&str>,
 ) -> Result<()> {
     let src_path = repo_path.join("src");
     let header_path = src_path.join("tree_sitter");
 
     // Read the grammar.json.
     let grammar_json = match grammar_path {
-        Some(path) => load_grammar_file(path.as_ref())?,
+        Some(path) => load_grammar_file(path.as_ref(), js_runtime)?,
         None => {
             let grammar_js_path = grammar_path.map_or(repo_path.join("grammar.js"), |s| s.into());
-            load_grammar_file(&grammar_js_path)?
+            load_grammar_file(&grammar_js_path, js_runtime)?
         }
     };
 
@@ -156,16 +157,15 @@ fn generate_parser_for_grammar_with_opts(
     })
 }
 
-pub fn load_grammar_file(grammar_path: &Path) -> Result<String> {
+pub fn load_grammar_file(grammar_path: &Path, js_runtime: Option<&str>) -> Result<String> {
     if grammar_path.is_dir() {
         return Err(anyhow!(
             "Path to a grammar file with `.js` or `.json` extension is required"
         ));
     }
     match grammar_path.extension().and_then(|e| e.to_str()) {
-        Some("js") => {
-            Ok(load_js_grammar_file(grammar_path).with_context(|| "Failed to load grammar.js")?)
-        }
+        Some("js") => Ok(load_js_grammar_file(grammar_path, js_runtime)
+            .with_context(|| "Failed to load grammar.js")?),
         Some("json") => {
             Ok(fs::read_to_string(grammar_path).with_context(|| "Failed to load grammar.json")?)
         }
@@ -176,14 +176,17 @@ pub fn load_grammar_file(grammar_path: &Path) -> Result<String> {
     }
 }
 
-fn load_js_grammar_file(grammar_path: &Path) -> Result<String> {
+fn load_js_grammar_file(grammar_path: &Path, js_runtime: Option<&str>) -> Result<String> {
     let grammar_path = fs::canonicalize(grammar_path)?;
-    let mut node_process = Command::new("node")
+
+    let js_runtime = js_runtime.unwrap_or("node");
+
+    let mut node_process = Command::new(js_runtime)
         .env("TREE_SITTER_GRAMMAR_PATH", grammar_path)
         .stdin(Stdio::piped())
         .stdout(Stdio::piped())
         .spawn()
-        .with_context(|| "Failed to run `node`")?;
+        .with_context(|| format!("Failed to run `{js_runtime}`"))?;
 
     let mut node_stdin = node_process
         .stdin
diff --git a/cli/src/main.rs b/cli/src/main.rs
index fe250e68..f66864ff 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -126,6 +126,14 @@ fn run() -> Result<()> {
                         .long("report-states-for-rule")
                         .value_name("rule-name")
                         .takes_value(true),
+                )
+                .arg(
+                    Arg::with_name("js-runtime")
+                        .long("js-runtime")
+                        .takes_value(true)
+                        .value_name("executable")
+                        .env("TREE_SITTER_JS_RUNTIME")
+                        .help("Use a JavaScript runtime other than node"),
                 ),
         )
         .subcommand(
@@ -307,6 +315,7 @@ fn run() -> Result<()> {
             let debug_build = matches.is_present("debug-build");
             let build = matches.is_present("build");
             let libdir = matches.value_of("libdir");
+            let js_runtime = matches.value_of("js-runtime");
             let report_symbol_name = matches.value_of("report-states-for-rule").or_else(|| {
                 if matches.is_present("report-states") {
                     Some("")
@@ -336,6 +345,7 @@ fn run() -> Result<()> {
                 abi_version,
                 generate_bindings,
                 report_symbol_name,
+                js_runtime,
             )?;
             if build {
                 if let Some(path) = libdir {
diff --git a/cli/src/tests/corpus_test.rs b/cli/src/tests/corpus_test.rs
index 24e72398..a193c029 100644
--- a/cli/src/tests/corpus_test.rs
+++ b/cli/src/tests/corpus_test.rs
@@ -260,7 +260,7 @@ fn test_feature_corpus_files() {
             grammar_path = test_path.join("grammar.json");
         }
         let error_message_path = test_path.join("expected_error.txt");
-        let grammar_json = generate::load_grammar_file(&grammar_path).unwrap();
+        let grammar_json = generate::load_grammar_file(&grammar_path, None).unwrap();
         let generate_result = generate::generate_parser_for_grammar(&grammar_json);
 
         if error_message_path.exists() {