From 04592b3e4fb3deb0253c8ab708c9465c13694ea8 Mon Sep 17 00:00:00 2001
From: Boshen <boshenc@gmail.com>
Date: Mon, 10 Apr 2023 22:13:41 +0800
Subject: [PATCH] feat(cli): add --threads 1 option for rayon to use only 1
 threads

---
 crates/oxc_cli/src/lib.rs  | 8 +++++++-
 crates/oxc_cli/src/main.rs | 5 +++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/crates/oxc_cli/src/lib.rs b/crates/oxc_cli/src/lib.rs
index 7a7e5412f..b704f0889 100644
--- a/crates/oxc_cli/src/lib.rs
+++ b/crates/oxc_cli/src/lib.rs
@@ -3,7 +3,7 @@ mod lint;
 mod result;
 mod walk;
 
-use clap::Command;
+use clap::{Arg, Command};
 
 use crate::lint::lint_command;
 pub use crate::{
@@ -22,4 +22,10 @@ pub fn command() -> Command {
         .subcommand_required(true)
         .arg_required_else_help(true)
         .subcommand(lint_command())
+        .arg(
+            Arg::new("threads")
+                .long("threads")
+                .value_parser(clap::value_parser!(usize))
+                .help("Number of threads to use. Set to 1 for using only 1 CPU core."),
+        )
 }
diff --git a/crates/oxc_cli/src/main.rs b/crates/oxc_cli/src/main.rs
index bdfd9bacc..35e37e19c 100644
--- a/crates/oxc_cli/src/main.rs
+++ b/crates/oxc_cli/src/main.rs
@@ -12,6 +12,11 @@ use oxc_cli::{command, CliRunResult, LintOptions, LintRunner};
 
 fn main() -> CliRunResult {
     let matches = command().get_matches();
+
+    if let Some(threads) = matches.get_one::<usize>("threads") {
+        rayon::ThreadPoolBuilder::new().num_threads(*threads).build_global().unwrap();
+    }
+
     let Some((subcommand, matches)) = matches.subcommand() else {
         return CliRunResult::None
     };