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

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: nodejs#55502
Fixes: nodejs#55500
Refs: nodejs#52697
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Chemi Atlow <[email protected]>

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() {

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); }));

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); }));

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());

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());

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;

test/fixtures/es-modules/tla/export-async.mjs

@@ -0,0 +1,2 @@
+let hello = await Promise.resolve('world');
+export { hello };

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 };