fix(codegen): ignore node_modules and .git directories in watch mode (#335)

Prevent EMFILE (too many open files) errors by ignoring node_modules
and .git directories in chokidar's watch, matching TypeScript's
default ignored directories behavior.

Closes #321

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: mizdra

.changeset/fix-emfile-watch.md

@@ -0,0 +1,5 @@
+---
+'@css-modules-kit/codegen': patch
+---
+
+fix(codegen): ignore `node_modules` and `.git` directories in watch mode to prevent EMFILE errors

packages/codegen/src/runner.ts

@@ -1,10 +1,17 @@
 import type { Stats } from 'node:fs';
 import { rm } from 'node:fs/promises';
+import { basename } from '@css-modules-kit/core';
 import chokidar, { type FSWatcher } from 'chokidar';
 import { CMKDisabledError } from './error.js';
 import type { Logger } from './logger/logger.js';
 import { createProject, type Project } from './project.js';
 
+// The CSS Modules Kit also ignores the minimum set of directories that TypeScript typically ignores.
+// ref: https://github.com/microsoft/TypeScript/blob/87aa917befa8f6182f5535df3c77287209692a04/src/compiler/sys.ts#L562
+// ref: https://github.com/microsoft/TypeScript/blob/caf1aee269d1660b4d2a8b555c2d602c97cb28d7/src/compiler/utilities.ts#L9506
+// ref: https://github.com/mizdra/css-modules-kit/issues/321
+const ignoredDirname: readonly string[] = ['node_modules', '.git'];
+
 interface RunnerArgs {
   project: string;
   clean: boolean;
@@ -78,6 +85,8 @@ export async function runCMKInWatchMode(args: RunnerArgs, logger: Logger): Promi
       chokidar
         .watch(wildcardDirectory.fileName, {
           ignored: (fileName: string, stats?: Stats) => {
+            if (ignoredDirname.includes(basename(fileName))) return true;
+
             // The ignored function is called twice for the same path. The first time with stats undefined,
             // and the second time with stats provided.
             // In the first call, we can't determine if the path is a directory or file.