fix(watcher): allow debounce 0 and harden test

Author: PatrickSys

src/index.ts

@@ -747,7 +747,8 @@ async function main() {
   if (process.env.CODEBASE_CONTEXT_DEBUG) console.error('[DEBUG] Server ready');
 
   // Auto-refresh: watch for file changes and trigger incremental reindex
-  const debounceMs = parseInt(process.env.CODEBASE_CONTEXT_DEBOUNCE_MS ?? '', 10) || 2000;
+  const debounceEnv = Number.parseInt(process.env.CODEBASE_CONTEXT_DEBOUNCE_MS ?? '', 10);
+  const debounceMs = Number.isFinite(debounceEnv) && debounceEnv >= 0 ? debounceEnv : 2000;
   const stopWatcher = startFileWatcher({
     rootPath: ROOT_PATH,
     debounceMs,

tests/file-watcher.test.ts

@@ -77,8 +77,9 @@ describe('FileWatcher', () => {
     // Give chokidar a moment to finish initializing before the first write
     await new Promise((resolve) => setTimeout(resolve, 100));
     await fs.writeFile(path.join(tempDir, 'cancel.ts'), 'export const y = 99;');
-    // Let chokidar detect the event but stop before debounce fires
-    await new Promise((resolve) => setTimeout(resolve, 150));
+    // Let chokidar detect the event (including awaitWriteFinish stabilityThreshold)
+    // but stop before the debounce window expires.
+    await new Promise((resolve) => setTimeout(resolve, 350));
     stop();
     // Wait past where debounce would have fired
     await new Promise((resolve) => setTimeout(resolve, debounceMs + 200));