diff --git a/packages/commonjs/README.md b/packages/commonjs/README.md
index 37f63693e..ce6c9ed58 100644
--- a/packages/commonjs/README.md
+++ b/packages/commonjs/README.md
@@ -311,6 +311,26 @@ ES modules are _always_ parsed in strict mode. That means that certain non-stric
 
 Luckily, there is absolutely no good reason _not_ to use strict mode for everything — so the solution to this problem is to lobby the authors of those modules to update them.
 
+## Inter-plugin-communication
+
+This plugin exposes the result of its CommonJS file type detection for other plugins to use. You can access it via `this.getModuleInfo` or the `moduleParsed` hook:
+
+```js
+function cjsDetectionPlugin() {
+  return {
+    name: 'cjs-detection',
+    moduleParsed({
+      id,
+      meta: {
+        commonjs: { isCommonJS },
+      },
+    }) {
+      console.log(`File ${id} is CommonJS: ${isCommonJS}`);
+    },
+  };
+}
+```
+
 ## Meta
 
 [CONTRIBUTING](/.github/CONTRIBUTING.md)
diff --git a/packages/commonjs/package.json b/packages/commonjs/package.json
index e1b968514..c6c2a0495 100644
--- a/packages/commonjs/package.json
+++ b/packages/commonjs/package.json
@@ -47,7 +47,7 @@
     "require"
   ],
   "peerDependencies": {
-    "rollup": "^2.22.0"
+    "rollup": "^2.30.0"
   },
   "dependencies": {
     "@rollup/pluginutils": "^3.1.0",
@@ -63,7 +63,7 @@
     "@rollup/plugin-node-resolve": "^8.4.0",
     "locate-character": "^2.0.5",
     "require-relative": "^0.8.7",
-    "rollup": "^2.23.0",
+    "rollup": "^2.30.0",
     "shx": "^0.3.2",
     "source-map": "^0.7.3",
     "source-map-support": "^0.5.19",
diff --git a/packages/commonjs/src/index.js b/packages/commonjs/src/index.js
index b88441e76..c3f75a391 100644
--- a/packages/commonjs/src/index.js
+++ b/packages/commonjs/src/index.js
@@ -103,14 +103,13 @@ export default function commonjs(options = {}) {
       !dynamicRequireModuleSet.has(normalizePathSlashes(id)) &&
       (!hasCjsKeywords(code, ignoreGlobal) || (isEsModule && !options.transformMixedEsModules))
     ) {
-      setIsCjsPromise(id, false);
-      return null;
+      return { meta: { commonjs: { isCommonJS: false } } };
     }
 
     // avoid wrapping in createCommonjsModule, as this is a commonjsRegister call
     const disableWrap = isModuleRegistrationProxy(id, dynamicRequireModuleSet);
 
-    const transformed = transformCommonjs(
+    return transformCommonjs(
       this.parse,
       code,
       id,
@@ -124,9 +123,6 @@ export default function commonjs(options = {}) {
       commonDir,
       ast
     );
-
-    setIsCjsPromise(id, isEsModule ? false : Boolean(transformed));
-    return transformed;
   }
 
   return {
@@ -201,20 +197,25 @@ export default function commonjs(options = {}) {
         !id.startsWith(DYNAMIC_JSON_PREFIX) &&
         (!filter(id) || !extensions.includes(extName))
       ) {
-        setIsCjsPromise(id, null);
         return null;
       }
 
-      let transformed;
       try {
-        transformed = transformAndCheckExports.call(this, code, id);
+        return transformAndCheckExports.call(this, code, id);
       } catch (err) {
-        transformed = null;
-        setIsCjsPromise(id, false);
-        this.error(err, err.loc);
+        return this.error(err, err.loc);
       }
+    },
 
-      return transformed;
+    moduleParsed({ id, meta: { commonjs } }) {
+      if (commonjs) {
+        const isCjs = commonjs.isCommonJS;
+        if (isCjs != null) {
+          setIsCjsPromise(id, isCjs);
+          return;
+        }
+      }
+      setIsCjsPromise(id, null);
     }
   };
 }
diff --git a/packages/commonjs/src/is-cjs.js b/packages/commonjs/src/is-cjs.js
index 695441e63..5f4496c3a 100644
--- a/packages/commonjs/src/is-cjs.js
+++ b/packages/commonjs/src/is-cjs.js
@@ -1,4 +1,3 @@
-/* eslint-disable no-undefined */
 const isCjsPromises = new Map();
 
 export function getIsCjsPromise(id) {
@@ -8,7 +7,7 @@ export function getIsCjsPromise(id) {
   const promise = new Promise((resolve) => {
     isCjsPromise = {
       resolve,
-      promise: undefined
+      promise: null
     };
     isCjsPromises.set(id, isCjsPromise);
   });
@@ -22,9 +21,9 @@ export function setIsCjsPromise(id, resolution) {
   if (isCjsPromise) {
     if (isCjsPromise.resolve) {
       isCjsPromise.resolve(resolution);
-      isCjsPromise.resolve = undefined;
+      isCjsPromise.resolve = null;
     }
   } else {
-    isCjsPromises.set(id, { promise: Promise.resolve(resolution), resolve: undefined });
+    isCjsPromises.set(id, { promise: Promise.resolve(resolution), resolve: null });
   }
 }
diff --git a/packages/commonjs/src/transform.js b/packages/commonjs/src/transform.js
index f1f751ea1..299db1fd3 100644
--- a/packages/commonjs/src/transform.js
+++ b/packages/commonjs/src/transform.js
@@ -560,8 +560,7 @@ export function transformCommonjs(
     !usesCommonjsHelpers &&
     (ignoreGlobal || !uses.global)
   ) {
-    // not a CommonJS module
-    return null;
+    return { meta: { commonjs: { isCommonJS: false } } };
   }
 
   const importBlock = `${(usesCommonjsHelpers
@@ -698,5 +697,10 @@ export function transformCommonjs(
   code = magicString.toString();
   const map = sourceMap ? magicString.generateMap() : null;
 
-  return { code, map, syntheticNamedExports: isEsModule ? false : '__moduleExports' };
+  return {
+    code,
+    map,
+    syntheticNamedExports: isEsModule ? false : '__moduleExports',
+    meta: { commonjs: { isCommonJS: !isEsModule } }
+  };
 }
diff --git a/packages/commonjs/test/fixtures/function/expose-file-type-detection/_config.js b/packages/commonjs/test/fixtures/function/expose-file-type-detection/_config.js
new file mode 100644
index 000000000..037256b61
--- /dev/null
+++ b/packages/commonjs/test/fixtures/function/expose-file-type-detection/_config.js
@@ -0,0 +1,33 @@
+const path = require('path');
+
+const ID_MAIN = path.join(__dirname, 'main.js');
+const ID_OTHER = path.join(__dirname, 'other.js');
+
+module.exports = {
+  description: 'exposes cjs file type detection to other plugins',
+  options: {
+    input: [ID_MAIN, ID_OTHER],
+    plugins: [
+      {
+        moduleParsed({
+          id,
+          meta: {
+            commonjs: { isCommonJS }
+          }
+        }) {
+          if (id === ID_MAIN) {
+            if (isCommonJS !== false) {
+              throw new Error(
+                `Main file wrongly detected: isCommonJS === ${JSON.stringify(isCommonJS)}`
+              );
+            }
+          } else if (isCommonJS !== true) {
+            throw new Error(
+              `Other file wrongly detected: isCommonJS === ${JSON.stringify(isCommonJS)}`
+            );
+          }
+        }
+      }
+    ]
+  }
+};
diff --git a/packages/commonjs/test/fixtures/function/expose-file-type-detection/main.js b/packages/commonjs/test/fixtures/function/expose-file-type-detection/main.js
new file mode 100644
index 000000000..bc136e278
--- /dev/null
+++ b/packages/commonjs/test/fixtures/function/expose-file-type-detection/main.js
@@ -0,0 +1,3 @@
+import foo from './other.js';
+
+t.is(foo, 'foo');
diff --git a/packages/commonjs/test/fixtures/function/expose-file-type-detection/other.js b/packages/commonjs/test/fixtures/function/expose-file-type-detection/other.js
new file mode 100644
index 000000000..2651774ae
--- /dev/null
+++ b/packages/commonjs/test/fixtures/function/expose-file-type-detection/other.js
@@ -0,0 +1 @@
+module.exports = 'foo';
diff --git a/packages/commonjs/test/fixtures/samples/caching/dep.js b/packages/commonjs/test/fixtures/samples/caching/dep.js
new file mode 100644
index 000000000..88a7c1a14
--- /dev/null
+++ b/packages/commonjs/test/fixtures/samples/caching/dep.js
@@ -0,0 +1 @@
+exports.dep = 42;
diff --git a/packages/commonjs/test/fixtures/samples/caching/main.js b/packages/commonjs/test/fixtures/samples/caching/main.js
new file mode 100644
index 000000000..62d4e8ea2
--- /dev/null
+++ b/packages/commonjs/test/fixtures/samples/caching/main.js
@@ -0,0 +1,3 @@
+const dep = require('./dep');
+
+console.log(dep);
diff --git a/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js b/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js
new file mode 100644
index 000000000..2f80d6d4e
--- /dev/null
+++ b/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js
@@ -0,0 +1,20 @@
+const { workerData, parentPort } = require('worker_threads');
+
+const { rollup } = require('rollup');
+
+const commonjs = require('../../../../dist/index');
+const { getCodeFromBundle } = require('../../../helpers/util');
+
+generateCode(workerData);
+
+async function generateCode(cache) {
+  const code = await getCodeFromBundle(
+    await rollup({
+      input: 'fixtures/samples/caching/main.js',
+      cache,
+      plugins: [commonjs()]
+    })
+  );
+
+  parentPort.postMessage(code);
+}
diff --git a/packages/commonjs/test/snapshots/function.js.md b/packages/commonjs/test/snapshots/function.js.md
index 90242f534..5ea110f93 100644
--- a/packages/commonjs/test/snapshots/function.js.md
+++ b/packages/commonjs/test/snapshots/function.js.md
@@ -778,9 +778,11 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
+      var Path = require('path');␊
       ␊
-      var Path = _interopDefault(require('path'));␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
+      ␊
+      var Path__default = /*#__PURE__*/_interopDefaultLegacy(Path);␊
       ␊
       var commonjsGlobal = typeof globalThis !== 'undefined' ? globalThis : typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};␊
       ␊
@@ -931,7 +933,7 @@ Generated by [AVA](https://avajs.dev).
       ␊
       const basePath = `${process.cwd()}/fixtures/function/dynamic-require-absolute-paths`;␊
       ␊
-      t.is(commonjsRequire(Path.resolve(`${basePath}/submodule.js`),"/$$rollup_base$$/fixtures/function/dynamic-require-absolute-paths"), 'submodule');␊
+      t.is(commonjsRequire(Path__default['default'].resolve(`${basePath}/submodule.js`),"/$$rollup_base$$/fixtures/function/dynamic-require-absolute-paths"), 'submodule');␊
       ␊
       var main = {␊
       ␊
@@ -2986,19 +2988,25 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
+      var externalExports = require('external-cjs-exports');␊
+      var externalModuleExports = require('external-cjs-module-exports');␊
+      var externalNamed = require('external-esm-named');␊
+      var externalMixed = require('external-esm-mixed');␊
+      var externalDefault = require('external-esm-default');␊
       ␊
-      var externalExports = _interopDefault(require('external-cjs-exports'));␊
-      var externalModuleExports = _interopDefault(require('external-cjs-module-exports'));␊
-      var externalNamed = _interopDefault(require('external-esm-named'));␊
-      var externalMixed = _interopDefault(require('external-esm-mixed'));␊
-      var externalDefault = _interopDefault(require('external-esm-default'));␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
       ␊
-      t.deepEqual(externalExports, { foo: 'foo' }, 'external exports');␊
-      t.deepEqual(externalModuleExports, 'bar', 'external module exports');␊
-      t.deepEqual(externalNamed, { foo: 'foo' }, 'external named');␊
-      t.deepEqual(externalMixed, 'bar', 'external mixed');␊
-      t.deepEqual(externalDefault, 'bar', 'external default');␊
+      var externalExports__default = /*#__PURE__*/_interopDefaultLegacy(externalExports);␊
+      var externalModuleExports__default = /*#__PURE__*/_interopDefaultLegacy(externalModuleExports);␊
+      var externalNamed__default = /*#__PURE__*/_interopDefaultLegacy(externalNamed);␊
+      var externalMixed__default = /*#__PURE__*/_interopDefaultLegacy(externalMixed);␊
+      var externalDefault__default = /*#__PURE__*/_interopDefaultLegacy(externalDefault);␊
+      ␊
+      t.deepEqual(externalExports__default['default'], { foo: 'foo' }, 'external exports');␊
+      t.deepEqual(externalModuleExports__default['default'], 'bar', 'external module exports');␊
+      t.deepEqual(externalNamed__default['default'], { foo: 'foo' }, 'external named');␊
+      t.deepEqual(externalMixed__default['default'], 'bar', 'external mixed');␊
+      t.deepEqual(externalDefault__default['default'], 'bar', 'external default');␊
       ␊
       var main = {␊
       ␊
@@ -3015,14 +3023,40 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
-      ␊
-      var externalExports = _interopDefault(require('external-cjs-exports'));␊
-      var externalModuleExports = _interopDefault(require('external-cjs-module-exports'));␊
-      var externalNamed = _interopDefault(require('external-esm-named'));␊
-      var externalMixed = _interopDefault(require('external-esm-mixed'));␊
+      var externalExports = require('external-cjs-exports');␊
+      var externalModuleExports = require('external-cjs-module-exports');␊
+      var externalNamed = require('external-esm-named');␊
+      var externalMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
+      ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalExports__default = /*#__PURE__*/_interopDefaultLegacy(externalExports);␊
+      var externalModuleExports__default = /*#__PURE__*/_interopDefaultLegacy(externalModuleExports);␊
+      var externalNamed__default = /*#__PURE__*/_interopDefaultLegacy(externalNamed);␊
+      var externalMixed__default = /*#__PURE__*/_interopDefaultLegacy(externalMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       function getAugmentedNamespace(n) {␊
       	if (n.__esModule) return n;␊
       	var a = Object.defineProperty({}, '__esModule', {value: true});␊
@@ -3038,12 +3072,12 @@ Generated by [AVA](https://avajs.dev).
       	return a;␊
       }␊
       ␊
-      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault__namespace);␊
       ␊
-      t.deepEqual(externalExports, { foo: 'foo' }, 'external exports');␊
-      t.deepEqual(externalModuleExports, 'bar', 'external module exports');␊
-      t.deepEqual(externalNamed, { foo: 'foo' }, 'external named');␊
-      t.deepEqual(externalMixed, 'bar', 'external mixed');␊
+      t.deepEqual(externalExports__default['default'], { foo: 'foo' }, 'external exports');␊
+      t.deepEqual(externalModuleExports__default['default'], 'bar', 'external module exports');␊
+      t.deepEqual(externalNamed__default['default'], { foo: 'foo' }, 'external named');␊
+      t.deepEqual(externalMixed__default['default'], 'bar', 'external mixed');␊
       t.deepEqual(externalDefault, { default: 'bar' }, 'external default');␊
       ␊
       var main = {␊
@@ -3061,14 +3095,40 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
-      ␊
-      var externalExports = _interopDefault(require('external-cjs-exports'));␊
-      var externalModuleExports = _interopDefault(require('external-cjs-module-exports'));␊
-      var externalNamed = _interopDefault(require('external-esm-named'));␊
-      var externalMixed = _interopDefault(require('external-esm-mixed'));␊
+      var externalExports = require('external-cjs-exports');␊
+      var externalModuleExports = require('external-cjs-module-exports');␊
+      var externalNamed = require('external-esm-named');␊
+      var externalMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
+      ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalExports__default = /*#__PURE__*/_interopDefaultLegacy(externalExports);␊
+      var externalModuleExports__default = /*#__PURE__*/_interopDefaultLegacy(externalModuleExports);␊
+      var externalNamed__default = /*#__PURE__*/_interopDefaultLegacy(externalNamed);␊
+      var externalMixed__default = /*#__PURE__*/_interopDefaultLegacy(externalMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       function getAugmentedNamespace(n) {␊
       	if (n.__esModule) return n;␊
       	var a = Object.defineProperty({}, '__esModule', {value: true});␊
@@ -3084,12 +3144,12 @@ Generated by [AVA](https://avajs.dev).
       	return a;␊
       }␊
       ␊
-      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault__namespace);␊
       ␊
-      t.deepEqual(externalExports, { foo: 'foo' }, 'external exports');␊
-      t.deepEqual(externalModuleExports, 'bar', 'external module exports');␊
-      t.deepEqual(externalNamed, { foo: 'foo' }, 'external named');␊
-      t.deepEqual(externalMixed, 'bar', 'external mixed');␊
+      t.deepEqual(externalExports__default['default'], { foo: 'foo' }, 'external exports');␊
+      t.deepEqual(externalModuleExports__default['default'], 'bar', 'external module exports');␊
+      t.deepEqual(externalNamed__default['default'], { foo: 'foo' }, 'external named');␊
+      t.deepEqual(externalMixed__default['default'], 'bar', 'external mixed');␊
       t.deepEqual(externalDefault, { default: 'bar' }, 'external default');␊
       ␊
       var main = {␊
@@ -3111,6 +3171,30 @@ Generated by [AVA](https://avajs.dev).
       var externalEsmMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalEsmMixed__namespace = /*#__PURE__*/_interopNamespace(externalEsmMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       function getAugmentedNamespace(n) {␊
       	if (n.__esModule) return n;␊
       	var a = Object.defineProperty({}, '__esModule', {value: true});␊
@@ -3126,11 +3210,11 @@ Generated by [AVA](https://avajs.dev).
       	return a;␊
       }␊
       ␊
-      var externalNamed = /*@__PURE__*/getAugmentedNamespace(externalEsmNamed);␊
+      var externalNamed = /*@__PURE__*/getAugmentedNamespace(externalEsmNamed__namespace);␊
       ␊
-      var externalMixed = /*@__PURE__*/getAugmentedNamespace(externalEsmMixed);␊
+      var externalMixed = /*@__PURE__*/getAugmentedNamespace(externalEsmMixed__namespace);␊
       ␊
-      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault__namespace);␊
       ␊
       t.deepEqual(externalNamed, { foo: 'foo' }, 'external named');␊
       t.deepEqual(externalMixed, { default: 'bar', foo: 'foo' }, 'external mixed');␊
@@ -3151,19 +3235,25 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
+      var externalExports = require('external-cjs-exports');␊
+      var externalModuleExports = require('external-cjs-module-exports');␊
+      var externalNamed = require('external-esm-named');␊
+      var externalMixed = require('external-esm-mixed');␊
+      var externalDefault = require('external-esm-default');␊
       ␊
-      var externalExports = _interopDefault(require('external-cjs-exports'));␊
-      var externalModuleExports = _interopDefault(require('external-cjs-module-exports'));␊
-      var externalNamed = _interopDefault(require('external-esm-named'));␊
-      var externalMixed = _interopDefault(require('external-esm-mixed'));␊
-      var externalDefault = _interopDefault(require('external-esm-default'));␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
       ␊
-      t.deepEqual(externalExports, { foo: 'foo' }, 'external exports');␊
-      t.deepEqual(externalModuleExports, 'bar', 'external module exports');␊
-      t.deepEqual(externalNamed, { foo: 'foo' }, 'external named');␊
-      t.deepEqual(externalMixed, 'bar', 'external mixed');␊
-      t.deepEqual(externalDefault, 'bar', 'external default');␊
+      var externalExports__default = /*#__PURE__*/_interopDefaultLegacy(externalExports);␊
+      var externalModuleExports__default = /*#__PURE__*/_interopDefaultLegacy(externalModuleExports);␊
+      var externalNamed__default = /*#__PURE__*/_interopDefaultLegacy(externalNamed);␊
+      var externalMixed__default = /*#__PURE__*/_interopDefaultLegacy(externalMixed);␊
+      var externalDefault__default = /*#__PURE__*/_interopDefaultLegacy(externalDefault);␊
+      ␊
+      t.deepEqual(externalExports__default['default'], { foo: 'foo' }, 'external exports');␊
+      t.deepEqual(externalModuleExports__default['default'], 'bar', 'external module exports');␊
+      t.deepEqual(externalNamed__default['default'], { foo: 'foo' }, 'external named');␊
+      t.deepEqual(externalMixed__default['default'], 'bar', 'external mixed');␊
+      t.deepEqual(externalDefault__default['default'], 'bar', 'external default');␊
       ␊
       var main = {␊
       ␊
@@ -3216,6 +3306,25 @@ Generated by [AVA](https://avajs.dev).
       `,
     }
 
+## expose-file-type-detection
+
+> Snapshot 1
+
+    {
+      'main.js': `'use strict';␊
+      ␊
+      var other = require('./other.js');␊
+      ␊
+      t.is(other, 'foo');␊
+      `,
+      'other.js': `'use strict';␊
+      ␊
+      var other = 'foo';␊
+      ␊
+      module.exports = other;␊
+      `,
+    }
+
 ## external-imports
 
 > Snapshot 1
@@ -3223,11 +3332,13 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
+      var foo = require('foo');␊
       ␊
-      var foo = _interopDefault(require('foo'));␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
       ␊
-      var main = foo;␊
+      var foo__default = /*#__PURE__*/_interopDefaultLegacy(foo);␊
+      ␊
+      var main = foo__default['default'];␊
       ␊
       module.exports = main;␊
       `,
@@ -3363,6 +3474,30 @@ Generated by [AVA](https://avajs.dev).
       var externalEsmMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalEsmMixed__namespace = /*#__PURE__*/_interopNamespace(externalEsmMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       const foo = 'foo';␊
       ␊
       var named = /*#__PURE__*/Object.freeze({␊
@@ -3389,11 +3524,11 @@ Generated by [AVA](https://avajs.dev).
       	return n && Object.prototype.hasOwnProperty.call(n, 'default') && Object.keys(n).length === 1 ? n['default'] : n;␊
       }␊
       ␊
-      var externalNamed = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmNamed);␊
+      var externalNamed = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmNamed__namespace);␊
       ␊
-      var externalMixed = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmMixed);␊
+      var externalMixed = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmMixed__namespace);␊
       ␊
-      var externalDefault = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmDefault__namespace);␊
       ␊
       t.deepEqual(named, { foo: 'foo' }, 'named exports');␊
       t.deepEqual(mixed$1, { foo: 'foo', default: 'bar' }, 'mixed exports');␊
@@ -3422,6 +3557,30 @@ Generated by [AVA](https://avajs.dev).
       var externalEsmMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalEsmMixed__namespace = /*#__PURE__*/_interopNamespace(externalEsmMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       const foo = 'foo';␊
       ␊
       var named = /*#__PURE__*/Object.freeze({␊
@@ -3464,11 +3623,11 @@ Generated by [AVA](https://avajs.dev).
       	return a;␊
       }␊
       ␊
-      var externalNamed = /*@__PURE__*/getAugmentedNamespace(externalEsmNamed);␊
+      var externalNamed = /*@__PURE__*/getAugmentedNamespace(externalEsmNamed__namespace);␊
       ␊
-      var externalMixed = /*@__PURE__*/getAugmentedNamespace(externalEsmMixed);␊
+      var externalMixed = /*@__PURE__*/getAugmentedNamespace(externalEsmMixed__namespace);␊
       ␊
-      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault__namespace);␊
       ␊
       var namedExports = /*@__PURE__*/getAugmentedNamespace(named);␊
       ␊
@@ -3633,12 +3792,36 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
-      ␊
       var externalEsmNamed = require('external-esm-named');␊
-      var externalMixed = _interopDefault(require('external-esm-mixed'));␊
+      var externalMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
+      ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalMixed__default = /*#__PURE__*/_interopDefaultLegacy(externalMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       function getDefaultExportFromNamespaceIfNotNamed (n) {␊
       	return n && Object.prototype.hasOwnProperty.call(n, 'default') && Object.keys(n).length === 1 ? n['default'] : n;␊
       }␊
@@ -3658,12 +3841,12 @@ Generated by [AVA](https://avajs.dev).
       	return a;␊
       }␊
       ␊
-      var externalNamed = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmNamed);␊
+      var externalNamed = /*@__PURE__*/getDefaultExportFromNamespaceIfNotNamed(externalEsmNamed__namespace);␊
       ␊
-      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault__namespace);␊
       ␊
       t.deepEqual(externalNamed, { foo: 'foo' }, 'named');␊
-      t.deepEqual(externalMixed, 'bar', 'mixed');␊
+      t.deepEqual(externalMixed__default['default'], 'bar', 'mixed');␊
       t.deepEqual(externalDefault, { default: 'bar' }, 'default');␊
       ␊
       var main = {␊
@@ -3685,6 +3868,30 @@ Generated by [AVA](https://avajs.dev).
       var externalEsmMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalEsmMixed__namespace = /*#__PURE__*/_interopNamespace(externalEsmMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       const foo = 'foo';␊
       ␊
       var named = /*#__PURE__*/Object.freeze({␊
@@ -3716,9 +3923,9 @@ Generated by [AVA](https://avajs.dev).
       t.deepEqual(mixed$1, { foo: 'foo', default: 'bar' }, 'mixed exports');␊
       t.deepEqual(_default$1, { default: 'bar' }, 'default export');␊
       t.deepEqual(none, {}, 'no exports');␊
-      t.deepEqual(externalEsmNamed, { foo: 'foo' }, 'external named');␊
-      t.deepEqual(externalEsmMixed, { foo: 'foo', default: 'bar' }, 'external mixed');␊
-      t.deepEqual(externalEsmDefault, { default: 'bar' }, 'external default');␊
+      t.deepEqual(externalEsmNamed__namespace, { foo: 'foo' }, 'external named');␊
+      t.deepEqual(externalEsmMixed__namespace, { foo: 'foo', default: 'bar' }, 'external mixed');␊
+      t.deepEqual(externalEsmDefault__namespace, { default: 'bar' }, 'external default');␊
       ␊
       var main = {␊
       ␊
@@ -3739,6 +3946,30 @@ Generated by [AVA](https://avajs.dev).
       var externalEsmMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalEsmMixed__namespace = /*#__PURE__*/_interopNamespace(externalEsmMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       const foo = 'foo';␊
       ␊
       var named = /*#__PURE__*/Object.freeze({␊
@@ -3758,11 +3989,11 @@ Generated by [AVA](https://avajs.dev).
       	return n && Object.prototype.hasOwnProperty.call(n, 'default') ? n['default'] : n;␊
       }␊
       ␊
-      var externalNamed = /*@__PURE__*/getDefaultExportFromNamespaceIfPresent(externalEsmNamed);␊
+      var externalNamed = /*@__PURE__*/getDefaultExportFromNamespaceIfPresent(externalEsmNamed__namespace);␊
       ␊
-      var externalMixed = /*@__PURE__*/getDefaultExportFromNamespaceIfPresent(externalEsmMixed);␊
+      var externalMixed = /*@__PURE__*/getDefaultExportFromNamespaceIfPresent(externalEsmMixed__namespace);␊
       ␊
-      var externalDefault = /*@__PURE__*/getDefaultExportFromNamespaceIfPresent(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getDefaultExportFromNamespaceIfPresent(externalEsmDefault__namespace);␊
       ␊
       t.deepEqual(named, { foo: 'foo' }, 'named exports');␊
       t.deepEqual(mixedExports, 'bar', 'mixed exports');␊
@@ -3787,11 +4018,15 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
+      var externalNamed = require('external-esm-named');␊
+      var externalMixed = require('external-esm-mixed');␊
+      var externalDefault = require('external-esm-default');␊
+      ␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
       ␊
-      var externalNamed = _interopDefault(require('external-esm-named'));␊
-      var externalMixed = _interopDefault(require('external-esm-mixed'));␊
-      var externalDefault = _interopDefault(require('external-esm-default'));␊
+      var externalNamed__default = /*#__PURE__*/_interopDefaultLegacy(externalNamed);␊
+      var externalMixed__default = /*#__PURE__*/_interopDefaultLegacy(externalMixed);␊
+      var externalDefault__default = /*#__PURE__*/_interopDefaultLegacy(externalDefault);␊
       ␊
       var mixedExports = 'bar';␊
       ␊
@@ -3799,9 +4034,9 @@ Generated by [AVA](https://avajs.dev).
       ␊
       t.deepEqual(mixedExports, 'bar', 'mixed exports');␊
       t.deepEqual(defaultExport, 'bar', 'default export');␊
-      t.deepEqual(externalNamed, { foo: 'foo' }, 'external named');␊
-      t.deepEqual(externalMixed, 'bar', 'external mixed');␊
-      t.deepEqual(externalDefault, 'bar', 'external default');␊
+      t.deepEqual(externalNamed__default['default'], { foo: 'foo' }, 'external named');␊
+      t.deepEqual(externalMixed__default['default'], 'bar', 'external mixed');␊
+      t.deepEqual(externalDefault__default['default'], 'bar', 'external default');␊
       ␊
       var main = {␊
       ␊
@@ -3822,6 +4057,30 @@ Generated by [AVA](https://avajs.dev).
       var externalEsmMixed = require('external-esm-mixed');␊
       var externalEsmDefault = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var externalEsmNamed__namespace = /*#__PURE__*/_interopNamespace(externalEsmNamed);␊
+      var externalEsmMixed__namespace = /*#__PURE__*/_interopNamespace(externalEsmMixed);␊
+      var externalEsmDefault__namespace = /*#__PURE__*/_interopNamespace(externalEsmDefault);␊
+      ␊
       const foo = 'foo';␊
       ␊
       var named = /*#__PURE__*/Object.freeze({␊
@@ -3864,11 +4123,11 @@ Generated by [AVA](https://avajs.dev).
       	return a;␊
       }␊
       ␊
-      var externalNamed = /*@__PURE__*/getAugmentedNamespace(externalEsmNamed);␊
+      var externalNamed = /*@__PURE__*/getAugmentedNamespace(externalEsmNamed__namespace);␊
       ␊
-      var externalMixed = /*@__PURE__*/getAugmentedNamespace(externalEsmMixed);␊
+      var externalMixed = /*@__PURE__*/getAugmentedNamespace(externalEsmMixed__namespace);␊
       ␊
-      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault);␊
+      var externalDefault = /*@__PURE__*/getAugmentedNamespace(externalEsmDefault__namespace);␊
       ␊
       var namedExports = /*@__PURE__*/getAugmentedNamespace(named);␊
       ␊
@@ -4718,9 +4977,11 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
+      var external = require('external-esm-default');␊
+      ␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
       ␊
-      var external = _interopDefault(require('external-esm-default'));␊
+      var external__default = /*#__PURE__*/_interopDefaultLegacy(external);␊
       ␊
       function getDefaultExportFromCjs (x) {␊
       	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;␊
@@ -4748,7 +5009,7 @@ Generated by [AVA](https://avajs.dev).
       var dep$1 = /*@__PURE__*/getDefaultExportFromCjs(dep);␊
       ␊
       t.is(dep$1, 'default');␊
-      t.is(external, 'bar');␊
+      t.is(external__default['default'], 'bar');␊
       `,
     }
 
@@ -4933,10 +5194,11 @@ Generated by [AVA](https://avajs.dev).
     {
       'main.js': `'use strict';␊
       ␊
-      function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }␊
-      ␊
       var external = require('external-esm-mixed');␊
-      var external__default = _interopDefault(external);␊
+      ␊
+      function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }␊
+      ␊
+      var external__default = /*#__PURE__*/_interopDefaultLegacy(external);␊
       ␊
       function getDefaultExportFromCjs (x) {␊
       	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;␊
@@ -4966,7 +5228,7 @@ Generated by [AVA](https://avajs.dev).
       ␊
       t.is(dep$1, 'default');␊
       t.is(dep.named, 'named');␊
-      t.is(external__default, 'bar');␊
+      t.is(external__default['default'], 'bar');␊
       t.is(external.foo, 'foo');␊
       `,
     }
@@ -5013,6 +5275,28 @@ Generated by [AVA](https://avajs.dev).
       ␊
       var external = require('external-esm-default');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var external__namespace = /*#__PURE__*/_interopNamespace(external);␊
+      ␊
       function getDefaultExportFromCjs (x) {␊
       	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;␊
       }␊
@@ -5046,7 +5330,7 @@ Generated by [AVA](https://avajs.dev).
         default: 'default'␊
       });␊
       ␊
-      t.deepEqual(external, {␊
+      t.deepEqual(external__namespace, {␊
         default: 'bar'␊
       });␊
       `,
@@ -5061,6 +5345,28 @@ Generated by [AVA](https://avajs.dev).
       ␊
       var external = require('external-esm-mixed');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var external__namespace = /*#__PURE__*/_interopNamespace(external);␊
+      ␊
       function getDefaultExportFromCjs (x) {␊
       	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;␊
       }␊
@@ -5096,7 +5402,7 @@ Generated by [AVA](https://avajs.dev).
         named: 'named'␊
       });␊
       ␊
-      t.deepEqual(external, {␊
+      t.deepEqual(external__namespace, {␊
         default: 'bar',␊
         foo: 'foo'␊
       });␊
@@ -5112,6 +5418,28 @@ Generated by [AVA](https://avajs.dev).
       ␊
       var external = require('external-esm-named');␊
       ␊
+      function _interopNamespace(e) {␊
+      	if (e && e.__esModule) return e;␊
+      	var n = Object.create(null);␊
+      	if (e) {␊
+      		Object.keys(e).forEach(function (k) {␊
+      			if (k !== 'default') {␊
+      				var d = Object.getOwnPropertyDescriptor(e, k);␊
+      				Object.defineProperty(n, k, d.get ? d : {␊
+      					enumerable: true,␊
+      					get: function () {␊
+      						return e[k];␊
+      					}␊
+      				});␊
+      			}␊
+      		});␊
+      	}␊
+      	n['default'] = e;␊
+      	return Object.freeze(n);␊
+      }␊
+      ␊
+      var external__namespace = /*#__PURE__*/_interopNamespace(external);␊
+      ␊
       function getDefaultExportFromCjs (x) {␊
       	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;␊
       }␊
@@ -5151,7 +5479,7 @@ Generated by [AVA](https://avajs.dev).
         default: { named: 'named' }␊
       });␊
       ␊
-      t.deepEqual(external, {␊
+      t.deepEqual(external__namespace, {␊
         foo: 'foo'␊
       });␊
       `,
diff --git a/packages/commonjs/test/snapshots/function.js.snap b/packages/commonjs/test/snapshots/function.js.snap
index 3dd4848a5..d4f280d77 100644
Binary files a/packages/commonjs/test/snapshots/function.js.snap and b/packages/commonjs/test/snapshots/function.js.snap differ
diff --git a/packages/commonjs/test/test.js b/packages/commonjs/test/test.js
index b096d5bd7..17a8b6129 100644
--- a/packages/commonjs/test/test.js
+++ b/packages/commonjs/test/test.js
@@ -1,12 +1,13 @@
 /* eslint-disable line-comment-position, no-new-func, no-undefined */
 import * as path from 'path';
 
+import resolve from '@rollup/plugin-node-resolve';
+
 import test from 'ava';
-import { SourceMapConsumer } from 'source-map';
-import { install } from 'source-map-support';
 import { getLocator } from 'locate-character';
 import { rollup } from 'rollup';
-import resolve from '@rollup/plugin-node-resolve';
+import { SourceMapConsumer } from 'source-map';
+import { install } from 'source-map-support';
 
 import { testBundle } from '../../../util/test';
 
@@ -722,3 +723,26 @@ test('does not wrap commonjsRegister calls in createCommonjsModule', async (t) =
 
   t.not(/createCommonjsModule\(function/.test(code), true);
 });
+
+// This test uses worker threads to simulate an empty internal cache and needs at least Node 12
+if (Number(/^v(\d+)/.exec(process.version)[1]) >= 12) {
+  test('can be cached across instances', async (t) => {
+    const bundle = await rollup({
+      input: 'fixtures/samples/caching/main.js',
+      plugins: [commonjs()]
+    });
+    const { cache } = bundle;
+    const code = await getCodeFromBundle(bundle);
+
+    // We do a second run in a worker so that all internal state is cleared
+    const { Worker } = await import('worker_threads');
+    const getRollupUpCodeWithCache = new Worker(
+      path.join(__dirname, 'fixtures/samples/caching/rollupWorker.js'),
+      {
+        workerData: cache
+      }
+    );
+
+    t.is(code, await new Promise((done) => getRollupUpCodeWithCache.on('message', done)));
+  });
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index d996e6600..901d68cc0 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -135,7 +135,7 @@ importers:
       typescript: ^3.9.7
   packages/commonjs:
     dependencies:
-      '@rollup/pluginutils': 3.1.0_rollup@2.23.0
+      '@rollup/pluginutils': 3.1.0_rollup@2.30.0
       commondir: 1.0.1
       estree-walker: 2.0.1
       glob: 7.1.6
@@ -143,11 +143,11 @@ importers:
       magic-string: 0.25.7
       resolve: 1.17.0
     devDependencies:
-      '@rollup/plugin-json': 4.1.0_rollup@2.23.0
-      '@rollup/plugin-node-resolve': 8.4.0_rollup@2.23.0
+      '@rollup/plugin-json': 4.1.0_rollup@2.30.0
+      '@rollup/plugin-node-resolve': 8.4.0_rollup@2.30.0
       locate-character: 2.0.5
       require-relative: 0.8.7
-      rollup: 2.23.0
+      rollup: 2.30.0
       shx: 0.3.2
       source-map: 0.7.3
       source-map-support: 0.5.19
@@ -164,7 +164,7 @@ importers:
       magic-string: ^0.25.7
       require-relative: ^0.8.7
       resolve: ^1.17.0
-      rollup: ^2.23.0
+      rollup: ^2.30.0
       shx: ^0.3.2
       source-map: ^0.7.3
       source-map-support: ^0.5.19
@@ -1576,6 +1576,15 @@ packages:
       rollup: ^1.20.0 || ^2.0.0
     resolution:
       integrity: sha512-yfLbTdNS6amI/2OpmbiBoW12vngr5NW2jCJVZSBEz+H5KfUJZ2M7sDjk0U6GOOdCWFVScShte29o9NezJ53TPw==
+  /@rollup/plugin-json/4.1.0_rollup@2.30.0:
+    dependencies:
+      '@rollup/pluginutils': 3.1.0_rollup@2.30.0
+      rollup: 2.30.0
+    dev: true
+    peerDependencies:
+      rollup: ^1.20.0 || ^2.0.0
+    resolution:
+      integrity: sha512-yfLbTdNS6amI/2OpmbiBoW12vngr5NW2jCJVZSBEz+H5KfUJZ2M7sDjk0U6GOOdCWFVScShte29o9NezJ53TPw==
   /@rollup/plugin-node-resolve/8.4.0_rollup@2.23.0:
     dependencies:
       '@rollup/pluginutils': 3.1.0_rollup@2.23.0
@@ -1593,6 +1602,23 @@ packages:
       rollup: ^1.20.0||^2.0.0
     resolution:
       integrity: sha512-LFqKdRLn0ShtQyf6SBYO69bGE1upV6wUhBX0vFOUnLAyzx5cwp8svA0eHUnu8+YU57XOkrMtfG63QOpQx25pHQ==
+  /@rollup/plugin-node-resolve/8.4.0_rollup@2.30.0:
+    dependencies:
+      '@rollup/pluginutils': 3.1.0_rollup@2.30.0
+      '@types/resolve': 1.17.1
+      builtin-modules: 3.1.0
+      deep-freeze: 0.0.1
+      deepmerge: 4.2.2
+      is-module: 1.0.0
+      resolve: 1.17.0
+      rollup: 2.30.0
+    dev: true
+    engines:
+      node: '>= 8.0.0'
+    peerDependencies:
+      rollup: ^1.20.0||^2.0.0
+    resolution:
+      integrity: sha512-LFqKdRLn0ShtQyf6SBYO69bGE1upV6wUhBX0vFOUnLAyzx5cwp8svA0eHUnu8+YU57XOkrMtfG63QOpQx25pHQ==
   /@rollup/plugin-typescript/5.0.2_rollup@2.23.0:
     dependencies:
       '@rollup/pluginutils': 3.1.0_rollup@2.23.0
@@ -1656,6 +1682,18 @@ packages:
       rollup: ^1.20.0||^2.0.0
     resolution:
       integrity: sha512-GksZ6pr6TpIjHm8h9lSQ8pi8BE9VeubNT0OMJ3B5uZJ8pz73NPiqOtCog/x2/QzM1ENChPKxMDhiQuRHsqc+lg==
+  /@rollup/pluginutils/3.1.0_rollup@2.30.0:
+    dependencies:
+      '@types/estree': 0.0.39
+      estree-walker: 1.0.1
+      picomatch: 2.2.2
+      rollup: 2.30.0
+    engines:
+      node: '>= 8.0.0'
+    peerDependencies:
+      rollup: ^1.20.0||^2.0.0
+    resolution:
+      integrity: sha512-GksZ6pr6TpIjHm8h9lSQ8pi8BE9VeubNT0OMJ3B5uZJ8pz73NPiqOtCog/x2/QzM1ENChPKxMDhiQuRHsqc+lg==
   /@sindresorhus/is/0.14.0:
     dev: true
     engines:
@@ -6400,6 +6438,15 @@ packages:
       fsevents: 2.1.3
     resolution:
       integrity: sha512-vLNmZFUGVwrnqNAJ/BvuLk1MtWzu4IuoqsH9UWK5AIdO3rt8/CSiJNvPvCIvfzrbNsqKbNzPAG1V2O4eTe2XZg==
+  /rollup/2.30.0:
+    dev: true
+    engines:
+      node: '>=10.0.0'
+    hasBin: true
+    optionalDependencies:
+      fsevents: 2.1.3
+    resolution:
+      integrity: sha512-j4K1hUZfgFM03DUpayd3c7kZW+2wDbI6rj7ssQxpCpL1vsGpaM0vSorxBuePFwQDFq9O2DI6AOQbm174Awsq4w==
   /run-async/2.4.1:
     dev: true
     engines: