feat: introduce new loadInclude hook (#157)

README.md

@@ -24,6 +24,7 @@ Currently supports:
 | [`transform`](https://rollupjs.org/guide/en/#transformers) | ✅ | ✅ | ✅ | ✅ | ✅ <sup>3</sup> |
 | [`enforce`](https://rollupjs.org/guide/en/#enforce) | ❌ <sup>2</sup> | ✅ | ✅ | ✅ | ❌ <sup>2</sup> |
 | [`resolveId`](https://rollupjs.org/guide/en/#resolveid) | ✅ | ✅ | ✅ | ✅ | ✅ |
+| `loadInclude`<sup>1</sup> | ✅ | ✅ | ✅ | ✅ | ✅ |
 | [`load`](https://rollupjs.org/guide/en/#load) | ✅ | ✅ | ✅ | ✅ | ✅ <sup>3</sup> |
 | [`watchChange`](https://rollupjs.org/guide/en/#watchchange) | ✅ | ✅ | ✅ | ✅ | ✅ |
 

src/esbuild/index.ts

@@ -132,7 +132,7 @@ export function getEsbuildPlugin <UserOptions = {}> (
 
               let code: string | undefined, map: SourceMap | null | undefined
 
-              if (plugin.load) {
+              if (plugin.load && (!plugin.loadInclude || plugin.loadInclude(id))) {
                 const result = await plugin.load.call(Object.assign(context, pluginContext), id)
                 if (typeof result === 'string') {
                   code = result

src/rollup/index.ts

@@ -23,6 +23,16 @@ export function toRollupPlugin (plugin: UnpluginOptions, containRollupOptions =
     }
   }
 
+  if (plugin.load && plugin.loadInclude) {
+    const _load = plugin.load
+    plugin.load = function (id) {
+      if (plugin.loadInclude && !plugin.loadInclude(id)) {
+        return null
+      }
+      return _load.call(this, id)
+    }
+  }
+
   if (plugin.rollup && containRollupOptions) {
     Object.assign(plugin, plugin.rollup)
   }

src/types.ts

@@ -27,14 +27,25 @@ export interface UnpluginBuildContext {
 export interface UnpluginOptions {
   name: string;
   enforce?: 'post' | 'pre' | undefined;
+
   buildStart?: (this: UnpluginBuildContext) => Promise<void> | void;
   buildEnd?: (this: UnpluginBuildContext) => Promise<void> | void;
-  transformInclude?: (id: string) => boolean | null | undefined;
   transform?: (this: UnpluginBuildContext & UnpluginContext, code: string, id: string) => Thenable<TransformResult>;
   load?: (this: UnpluginBuildContext & UnpluginContext, id: string) => Thenable<TransformResult>
   resolveId?: (id: string, importer: string | undefined, options: { isEntry: boolean }) => Thenable<string | ExternalIdResult | null | undefined>
   watchChange?: (this: UnpluginBuildContext, id: string, change: { event: 'create' | 'update' | 'delete' }) => void
 
+  /**
+   * Custom predicate function to filter modules to be loaded.
+   * When omitted, all modules will be included (might have potential perf impact on Webpack).
+   */
+  loadInclude?: (id: string) => boolean | null | undefined;
+  /**
+   * Custom predicate function to filter modules to be transformed.
+   * When omitted, all modules will be included (might have potential perf impact on Webpack).
+   */
+  transformInclude?: (id: string) => boolean | null | undefined;
+
   // framework specify extends
   rollup?: Partial<RollupPlugin>
   webpack?: (compiler: WebpackCompiler) => void

src/webpack/index.ts

@@ -160,14 +160,18 @@ export function getWebpackPlugin<UserOptions = {}> (
         // load hook
         if (plugin.load) {
           compiler.options.module.rules.push({
-            include (id) { // Don't run load hook for external modules
+            include (id) {
               if (id.startsWith(plugin.__virtualModulePrefix)) {
-                // If module is a virtual one, we first need to strip its prefix and decode it
-                const decodedId = decodeURIComponent(id.slice(plugin.__virtualModulePrefix.length))
-                return !externalModules.has(decodedId)
-              } else {
-                return !externalModules.has(id)
+                id = decodeURIComponent(id.slice(plugin.__virtualModulePrefix.length))
               }
+
+              // load include filter
+              if (plugin.loadInclude && !plugin.loadInclude(id)) {
+                return false
+              }
+
+              // Don't run load hook for external modules
+              return !externalModules.has(id)
             },
             enforce: plugin.enforce,
             use: [{

test/fixtures/virtual-module/unplugin.js

@@ -6,14 +6,17 @@ module.exports = createUnplugin(() => {
     resolveId (id) {
       return id.startsWith('virtual/') ? id : null
     },
+    loadInclude (id) {
+      return id.startsWith('virtual/')
+    },
     load (id) {
       if (id === 'virtual/1') {
         return 'export default "VIRTUAL:ONE"'
-      }
-      if (id === 'virtual/2') {
+      } else if (id === 'virtual/2') {
         return 'export default "VIRTUAL:TWO"'
+      } else {
+        throw new Error(`Unexpected id: ${id}`)
       }
-      return null
     }
   }
 })