module: allow ESM that failed to be required to be re-imported

joyeecheung · RafaelGSS · commit a9e08cfe6d1f · 2024-11-01T16:00:12.000-03:00
When a ESM module cannot be loaded by require due to the presence of TLA, its module status would be stopped at kInstantiated. In this case, when it's imported again, we should allow it to be evaluated asynchronously, as it's also a common pattern for users to retry with dynamic import when require fails. PR-URL: #55502 Fixes: #55500 Refs: #52697 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
diff --git a/lib/internal/modules/esm/module_job.js b/lib/internal/modules/esm/module_job.js
@@ -22,7 +22,7 @@ let debug = require('internal/util/debuglog').debuglog('esm', (fn) => {
   debug = fn;
 });
 
-const { ModuleWrap, kEvaluated } = internalBinding('module_wrap');
+const { ModuleWrap, kInstantiated } = internalBinding('module_wrap');
 const {
   privateSymbols: {
     entry_point_module_private_symbol,
@@ -354,10 +354,26 @@ class ModuleJobSync extends ModuleJobBase {
   }
 
   async run() {
+    // This path is hit by a require'd module that is imported again.
     const status = this.module.getStatus();
-    assert(status === kEvaluated,
-           `A require()-d module that is imported again must be evaluated. Status = ${status}`);
-    return { __proto__: null, module: this.module };
+    if (status > kInstantiated) {
+      if (this.evaluationPromise) {
+        await this.evaluationPromise;
+      }
+      return { __proto__: null, module: this.module };
+    } else if (status === kInstantiated) {
+      // The evaluation may have been canceled because instantiateSync() detected TLA first.
+      // But when it is imported again, it's fine to re-evaluate it asynchronously.
+      const timeout = -1;
+      const breakOnSigint = false;
+      this.evaluationPromise = this.module.evaluate(timeout, breakOnSigint);
+      await this.evaluationPromise;
+      this.evaluationPromise = undefined;
+      return { __proto__: null, module: this.module };
+    }
+
+    assert.fail('Unexpected status of a module that is imported again after being required. ' +
+                `Status = ${status}`);
   }
 
   runSync() {
diff --git a/test/es-module/test-require-module-retry-import-errored.js b/test/es-module/test-require-module-retry-import-errored.js
@@ -0,0 +1,35 @@
+// This tests that after failing to require an ESM that contains TLA,
+// retrying with import() still works, and produces consistent results.
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const { exportedReject } = require('../fixtures/es-modules/tla/export-promise.mjs');
+
+assert.throws(() => {
+  require('../fixtures/es-modules/tla/await-export-promise.mjs');
+}, {
+  code: 'ERR_REQUIRE_ASYNC_MODULE'
+});
+
+const interval = setInterval(() => {}, 1000);  // Keep the test running, because await alone doesn't.
+const err = new Error('rejected');
+
+const p1 = import('../fixtures/es-modules/tla/await-export-promise.mjs')
+  .then(common.mustNotCall(), common.mustCall((e) => {
+    assert.strictEqual(e, err);
+  }));
+
+const p2 = import('../fixtures/es-modules/tla/await-export-promise.mjs')
+  .then(common.mustNotCall(), common.mustCall((e) => {
+    assert.strictEqual(e, err);
+  }));
+
+const p3 = import('../fixtures/es-modules/tla/await-export-promise.mjs')
+  .then(common.mustNotCall(), common.mustCall((e) => {
+    assert.strictEqual(e, err);
+  }));
+
+exportedReject(err);
+
+Promise.all([p1, p2, p3]).then(common.mustCall(() => { clearInterval(interval); }));
diff --git a/test/es-module/test-require-module-retry-import-evaluating.js b/test/es-module/test-require-module-retry-import-evaluating.js
@@ -0,0 +1,32 @@
+// This tests that after failing to require an ESM that contains TLA,
+// retrying with import() still works, and produces consistent results.
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const { exportedResolve } = require('../fixtures/es-modules/tla/export-promise.mjs');
+
+assert.throws(() => {
+  require('../fixtures/es-modules/tla/await-export-promise.mjs');
+}, {
+  code: 'ERR_REQUIRE_ASYNC_MODULE'
+});
+
+const interval = setInterval(() => {}, 1000);  // Keep the test running, because await alone doesn't.
+const value = { hello: 'world' };
+
+const p1 = import('../fixtures/es-modules/tla/await-export-promise.mjs').then(common.mustCall((ns) => {
+  assert.strictEqual(ns.default, value);
+}), common.mustNotCall());
+
+const p2 = import('../fixtures/es-modules/tla/await-export-promise.mjs').then(common.mustCall((ns) => {
+  assert.strictEqual(ns.default, value);
+}), common.mustNotCall());
+
+const p3 = import('../fixtures/es-modules/tla/await-export-promise.mjs').then(common.mustCall((ns) => {
+  assert.strictEqual(ns.default, value);
+}), common.mustNotCall());
+
+exportedResolve(value);
+
+Promise.all([p1, p2, p3]).then(common.mustCall(() => { clearInterval(interval); }));
diff --git a/test/es-module/test-require-module-tla-retry-import-2.js b/test/es-module/test-require-module-tla-retry-import-2.js
@@ -0,0 +1,26 @@
+// This tests that after loading a ESM with import() and then retrying
+// with require(), it errors as expected, and produces consistent results.
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+let ns;
+async function test() {
+  const newNs = await import('../fixtures/es-modules/tla/export-async.mjs');
+  if (ns === undefined) {
+    ns = newNs;
+  } else {
+    // Check that re-evalaution is returning the same namespace.
+    assert.strictEqual(ns, newNs);
+  }
+  assert.strictEqual(ns.hello, 'world');
+
+  assert.throws(() => {
+    require('../fixtures/es-modules/tla/export-async.mjs');
+  }, {
+    code: 'ERR_REQUIRE_ASYNC_MODULE'
+  });
+}
+
+// Run the test twice to check consistency after caching.
+test().then(common.mustCall(test)).catch(common.mustNotCall());
diff --git a/test/es-module/test-require-module-tla-retry-import.js b/test/es-module/test-require-module-tla-retry-import.js
@@ -0,0 +1,25 @@
+// This tests that after failing to require an ESM that contains TLA,
+// retrying with import() still works, and produces consistent results.
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+let ns;
+async function test() {
+  assert.throws(() => {
+    require('../fixtures/es-modules/tla/export-async.mjs');
+  }, {
+    code: 'ERR_REQUIRE_ASYNC_MODULE'
+  });
+  const newNs = await import('../fixtures/es-modules/tla/export-async.mjs');
+  if (ns === undefined) {
+    ns = newNs;
+  } else {
+    // Check that re-evalaution is returning the same namespace.
+    assert.strictEqual(ns, newNs);
+  }
+  assert.strictEqual(ns.hello, 'world');
+}
+
+// Run the test twice to check consistency after caching.
+test().then(common.mustCall(test)).catch(common.mustNotCall());
diff --git a/test/fixtures/es-modules/tla/await-export-promise.mjs b/test/fixtures/es-modules/tla/await-export-promise.mjs
@@ -0,0 +1,4 @@
+import promise from './export-promise.mjs';
+let result;
+result = await promise;
+export default result;
diff --git a/test/fixtures/es-modules/tla/export-async.mjs b/test/fixtures/es-modules/tla/export-async.mjs
@@ -0,0 +1,2 @@
+let hello = await Promise.resolve('world');
+export { hello };
diff --git a/test/fixtures/es-modules/tla/export-promise.mjs b/test/fixtures/es-modules/tla/export-promise.mjs
@@ -0,0 +1,8 @@
+let exportedResolve;
+let exportedReject;
+const promise = new Promise((resolve, reject) => {
+  exportedResolve = resolve;
+  exportedReject = reject;
+});
+export default promise;
+export { exportedResolve, exportedReject };

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+let hello = await Promise.resolve('world');`
	`2`	`+export { hello };`