feat(copy): add support for watching copy source files (#721)

schplitt · sxzz · web-flow · commit 7c23ad887919 · 2026-03-15T11:33:54.000Z
* feat: add support for watching copy source files

* refactor: move shared logic to `resolveCopyEntries`

* refactor

* refactor

* fix

---------

Co-authored-by: Kevin Deng &lt;sxzz@sxzz.moe&gt;
diff --git a/src/features/copy.ts b/src/features/copy.ts
@@ -36,15 +36,37 @@ export interface CopyEntry {
 export type CopyOptions = Arrayable<string | CopyEntry>
 export type CopyOptionsFn = (options: ResolvedConfig) => Awaitable<CopyOptions>
 
+type ResolvedCopyEntry = CopyEntry & { from: string; to: string }
+
 export async function copy(options: ResolvedConfig): Promise<void> {
   if (!options.copy) return
 
+  const resolved = await resolveCopyEntries(options)
+  await Promise.all(
+    resolved.map(({ from, to, verbose }) => {
+      if (verbose) {
+        options.logger.info(
+          options.nameLabel,
+          `Copying files from ${path.relative(options.cwd, from)} to ${path.relative(
+            options.cwd,
+            to,
+          )}`,
+        )
+      }
+      return fsCopy(from, to)
+    }),
+  )
+}
+
+export async function resolveCopyEntries(
+  options: ResolvedConfig,
+): Promise<ResolvedCopyEntry[]> {
   const copy = toArray(
     typeof options.copy === 'function'
       ? await options.copy(options)
       : options.copy,
   )
-  if (!copy.length) return
+  if (!copy.length) return []
 
   const resolved = (
     await Promise.all(
@@ -63,52 +85,44 @@ export async function copy(options: ResolvedConfig): Promise<void> {
           })
         }
 
-        return from.map((file) => resolveCopyEntry({ ...entry, from: file }))
+        return from.map((file) =>
+          resolveCopyEntry(
+            { ...entry, from: file },
+            options.cwd,
+            options.outDir,
+          ),
+        )
       }),
     )
   ).flat()
 
   if (!resolved.length) {
     options.logger.warn(options.nameLabel, `No files matched for copying.`)
-    return
   }
 
-  await Promise.all(
-    resolved.map(({ from, to, verbose }) => {
-      if (verbose) {
-        options.logger.info(
-          options.nameLabel,
-          `Copying files from ${path.relative(options.cwd, from)} to ${path.relative(
-            options.cwd,
-            to,
-          )}`,
-        )
-      }
-      return fsCopy(from, to)
-    }),
-  )
+  return resolved
+}
 
-  // https://github.com/vladshcherbin/rollup-plugin-copy/blob/master/src/index.js
-  // MIT License
-  function resolveCopyEntry(
-    entry: CopyEntry & { from: string },
-  ): CopyEntry & { from: string; to: string } {
-    const { flatten = true, rename } = entry
-    const from = path.resolve(options.cwd, entry.from)
-    const to = entry.to ? path.resolve(options.cwd, entry.to) : options.outDir
+// https://github.com/vladshcherbin/rollup-plugin-copy/blob/master/src/index.js
+// MIT License
+function resolveCopyEntry(
+  entry: CopyEntry & { from: string },
+  cwd: string,
+  outDir: string,
+): CopyEntry & { from: string; to: string } {
+  const { flatten = true, rename } = entry
+  const from = path.resolve(cwd, entry.from)
+  const to = entry.to ? path.resolve(cwd, entry.to) : outDir
 
-    const { base, dir } = path.parse(path.relative(options.cwd, from))
-    const destFolder =
-      flatten || (!flatten && !dir)
-        ? to
-        : dir.replace(dir.split(path.sep)[0], to)
-    const dest = path.join(
-      destFolder,
-      rename ? renameTarget(base, rename, from) : base,
-    )
+  const { base, dir } = path.parse(path.relative(cwd, from))
+  const destFolder =
+    flatten || (!flatten && !dir) ? to : dir.replace(dir.split(path.sep)[0], to)
+  const dest = path.join(
+    destFolder,
+    rename ? renameTarget(base, rename, from) : base,
+  )
 
-    return { ...entry, from, to: dest }
-  }
+  return { ...entry, from, to: dest }
 }
 
 function renameTarget(
diff --git a/src/features/watch.ts b/src/features/watch.ts
@@ -1,5 +1,6 @@
 import { addOutDirToChunks } from '../utils/chunks.ts'
 import { resolveComma, toArray } from '../utils/general.ts'
+import { resolveCopyEntries } from './copy.ts'
 import type { TsdownBundle } from '../config/types.ts'
 import type { Plugin } from 'rolldown'
 
@@ -19,7 +20,7 @@ export function WatchPlugin(
           inputOptions.watch.exclude.push(...config.ignoreWatch)
         }
       : undefined,
-    buildStart() {
+    async buildStart() {
       config.tsconfig && this.addWatchFile(config.tsconfig)
       for (const file of configFiles) {
         this.addWatchFile(file)
@@ -32,6 +33,15 @@ export function WatchPlugin(
       if (config.pkg) {
         this.addWatchFile(config.pkg.packageJsonPath)
       }
+
+      // Watch copy source files
+      if (config.copy) {
+        const resolvedEntries = await resolveCopyEntries(config)
+
+        for (const entry of resolvedEntries) {
+          this.addWatchFile(entry.from)
+        }
+      }
     },
     generateBundle: {
       order: 'post',
