fix: debounce onSuccess in watch mode to prevent duplicate execution

sxzz · sxzz · commit af748b1d2505 · 2026-02-10T22:48:15.000+08:00
closes #763
diff --git a/.gitignore b/.gitignore
@@ -17,3 +17,5 @@ docs/.vitepress/cache
 
 docs/reference/api
 docs/zh-CN/reference/api
+
+reproduction
diff --git a/eslint.config.js b/eslint.config.js
@@ -9,7 +9,7 @@ export default sxzz(
     },
   },
   {
-    ignores: ['skills/**/*.md'],
+    ignores: ['skills/**/*.md', 'reproduction/**'],
   },
   {
     files: ['templates/**'],
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
diff --git a/src/build.ts b/src/build.ts
@@ -29,7 +29,7 @@ import {
   type RolldownChunk,
   type TsdownBundle,
 } from './utils/chunks.ts'
-import { typeAssert } from './utils/general.ts'
+import { debounce, typeAssert } from './utils/general.ts'
 import { globalLogger } from './utils/logger.ts'
 
 const asyncDispose: typeof Symbol.asyncDispose =
@@ -146,12 +146,16 @@ async function buildSingle(
   const chunks: RolldownChunk[] = []
   let watcher: RolldownWatcher | undefined
   let ab: AbortController | undefined
+  const debouncedPostBuild = debounce(() => {
+    postBuild().catch((error) => logger.error(error))
+  }, 100)
 
   let updated = false
   const bundle: TsdownBundle = {
     chunks,
     config,
     async [asyncDispose]() {
+      debouncedPostBuild.cancel()
       ab?.abort()
       await watcher?.close()
     },
@@ -185,6 +189,12 @@ async function buildSingle(
     watcher.on('change', (id, event) => {
       if (event.event === 'update') {
         changedFile.push(id)
+        // Cancel pending postBuild immediately on file change,
+        // before the new build cycle starts. This prevents duplicate
+        // onSuccess execution when rapid file changes (e.g. VS Code
+        // auto-save) trigger multiple build cycles.
+        debouncedPostBuild.cancel()
+        ab?.abort()
       }
       if (configFiles.includes(id) || endsWithConfig.test(id)) {
         globalLogger.info(`Reload config: ${id}, restarting...`)
@@ -195,6 +205,8 @@ async function buildSingle(
     watcher.on('event', async (event) => {
       switch (event.code) {
         case 'START': {
+          debouncedPostBuild.cancel()
+
           if (config.clean.length) {
             await cleanChunks(config.outDir, chunks)
           }
@@ -206,7 +218,7 @@ async function buildSingle(
 
         case 'END': {
           if (!hasError) {
-            await postBuild()
+            debouncedPostBuild()
           }
           break
         }
diff --git a/src/utils/general.ts b/src/utils/general.ts
@@ -96,3 +96,16 @@ export function promiseWithResolvers<T>(): {
 export function typeAssert<T>(
   value: T,
 ): asserts value is Exclude<T, false | null | undefined> {}
+
+export function debounce<T extends (...args: any[]) => any>(
+  fn: T,
+  delay: number,
+): ((...args: Parameters<T>) => void) & { cancel: () => void } {
+  let timer: ReturnType<typeof setTimeout> | undefined
+  const debounced = (...args: Parameters<T>) => {
+    clearTimeout(timer)
+    timer = setTimeout(() => fn(...args), delay)
+  }
+  debounced.cancel = () => clearTimeout(timer)
+  return debounced
+}

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@ export default sxzz(`
`9`	`9`	`},`
`10`	`10`	`},`
`11`	`11`	`{`
`12`		`- ignores: ['skills/*/.md'],`
	`12`	`+ ignores: ['skills/*/.md', 'reproduction/**'],`
`13`	`13`	`},`
`14`	`14`	`{`
`15`	`15`	`files: ['templates/**'],`