filtered export

filtered-hook.mjs

@@ -0,0 +1,6 @@
+import { createHook } from './hook.js'
+import path from 'path'
+
+const { load, resolve, getFormat, getSource } = createHook(import.meta, new Set([path.join(import.meta.url, '../test/fixtures/export-types/default-expression-array.mjs').replace(':/', ':///')]))
+
+export { load, resolve, getFormat, getSource }

hook.js

@@ -229,7 +229,8 @@ function addIitm (url) {
 }
 
 // moduleList is an optional Set specifiying which modules need IITM patching
-// if moduleList is not set, IITM patches everything
+// moduleList contains full file paths
+// if moduleList is empty, IITM patches everything
 function createHook (meta, moduleList = new Set()) {
   async function resolve (specifier, context, parentResolve) {
     const { parentURL = '' } = context
@@ -243,6 +244,11 @@ function createHook (meta, moduleList = new Set()) {
       return { url: url.url, format: 'commonjs' }
     }
 
+    // early return if
+    if (moduleList.size && !moduleList.has(url.url) && url.url.startsWith('file:///')) {
+      return { url: url.url, format: url.format }
+    }
+
     if (isIitm(parentURL, meta) || hasIitm(parentURL)) {
       return url
     }
@@ -265,7 +271,6 @@ function createHook (meta, moduleList = new Set()) {
 
   const iitmURL = new URL('lib/register.js', meta.url).toString()
   async function getSource (url, context, parentGetSource) {
-    if (moduleList.size && !moduleList.has(url)) return parentGetSource(url, context, parentGetSource)
     if (hasIitm(url)) {
       const realUrl = deleteIitm(url)
       const { imports, namespaces, setters: mapSetters } = await processModule({

test/generic-loader.mjs

@@ -4,11 +4,13 @@
 
 import * as tsLoader from './typescript/iitm-ts-node-loader.mjs'
 import * as regularLoader from '../hook.mjs'
+import * as filteredLoader from '../filtered-hook.mjs'
 import path from 'path'
 
 const filename = process.env.IITM_TEST_FILE
 
 export const { load, resolve, getFormat, getSource } =
   filename.includes('disabled')
     ? {}
-    : (path.extname(filename).slice(-2) === 'ts' ? tsLoader : regularLoader)
+    : (path.extname(filename).slice(-2) === 'ts' ? tsLoader :
+    filename.endsWith('filtered-export.mjs') ? filteredLoader: regularLoader)

test/hook/filtered-export.mjs

@@ -0,0 +1,19 @@
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2.0 License.
+//
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021 Datadog, Inc.
+
+import Hook from '../../index.js'
+import a from '../fixtures/export-types/default-expression-array.mjs'
+import n from '../fixtures/export-types/default-expression-num.mjs'
+import { strictEqual } from 'assert'
+
+Hook((exports, name) => {
+  if (name.match(/default-expression-array\.m?js/)) {
+    exports.default[0] += 1
+  } else if (name.match(/default-expression-num\.m?js/)) {
+    exports.default += 1
+  }
+})
+
+strictEqual(a[0], 2)
+strictEqual(n, 1)