tidy: put node_modules under build

Author: lolbinarycat

src/tools/tidy/src/ext_tool_checks/rustdoc_js.rs

@@ -4,25 +4,39 @@
 use std::ffi::OsStr;
 use std::path::{Path, PathBuf};
 use std::process::Command;
+use std::fs;
 
 use build_helper::ci::CiEnv;
 use ignore::DirEntry;
 
 use crate::walk::walk_no_read;
 
+fn node_module_bin(name: &str) -> String {
+    format!("build/node_modules/.bin/{name}")
+}
+
 /// install all js dependencies from package.json.
 pub(super) fn npm_install() -> Result<(), super::Error> {
-    // disable a bunch of things we don't want.
-    // this makes tidy output less noisy, and also significantly improves runtime
-    // of repeated tidy invokations.
+    // will error if already exists, so ignore the error.
+    // if there is a filesystem permission issue,
+    // later commands will error.
+    let _ = fs::create_dir("build");
+    // copy stuff to build/ to make node_modules get put there.
+    fs::copy("package.json", "build/package.json")?;
+    fs::copy("package-lock.json", "build/package-lock.json")?;
+
     let mut cmd = Command::new("npm");
     if CiEnv::is_ci() {
         // `npm ci` redownloads every time and thus is too slow for local development.
         cmd.arg("ci");
     } else {
         cmd.arg("install");
     }
+    // disable a bunch of things we don't want.
+    // this makes tidy output less noisy, and also significantly improves runtime
+    // of repeated tidy invokations.
     cmd.args(&["--audit=false", "--save=false", "--fund=false"]);
+    cmd.current_dir("build");
     let mut child = cmd.spawn()?;
     match child.wait() {
         Ok(exit_status) => {
@@ -48,7 +62,7 @@ fn rustdoc_js_files(librustdoc_path: &Path) -> Vec<PathBuf> {
 }
 
 fn run_eslint(args: &[PathBuf], config_folder: PathBuf) -> Result<(), super::Error> {
-    let mut child = Command::new("node_modules/.bin/eslint")
+    let mut child = Command::new(node_module_bin("eslint"))
         .arg("-c")
         .arg(config_folder.join(".eslintrc.js"))
         .args(args)
@@ -130,7 +144,7 @@ pub(super) fn lint(
 
 pub(super) fn typecheck(librustdoc_path: &Path) -> Result<(), super::Error> {
     // use npx to ensure correct version
-    let mut child = Command::new("node_modules/.bin/tsc")
+    let mut child = Command::new(node_module_bin("tsc"))
         .arg("-p")
         .arg(librustdoc_path.join("html/static/js/tsconfig.json"))
         .spawn()?;
@@ -147,7 +161,7 @@ pub(super) fn typecheck(librustdoc_path: &Path) -> Result<(), super::Error> {
 
 pub(super) fn es_check(librustdoc_path: &Path) -> Result<(), super::Error> {
     let files_to_check = rustdoc_js_files(librustdoc_path);
-    let mut cmd = Command::new("node_modules/.bin/es-check");
+    let mut cmd = Command::new(node_module_bin("es-check"));
     cmd.arg("es2019");
     for f in files_to_check {
         cmd.arg(f);