module: await the cycle roots capability promise, if needed

lib/internal/modules/esm/module_job.js

@@ -649,10 +649,14 @@
       throw this.module.getError();
     }
     if (status > kInstantiated) {
-      // Already evaluated (e.g. previously require()'d and now import()'d again).
       if (this.evaluationPromise) {
+        // Evaluation was started by an earlier run() of this job and is still in flight.
         await this.evaluationPromise;
+      } else if (status === kEvaluated && this.module.hasAsyncGraph) {
+        // await the cycle root's capability promise.
+        await this.module.evaluate(-1, false);
       }
+      // Otherwise the module is already evaluated
       return { __proto__: null, module: this.module };
     }
     if (status < kInstantiated) {

test/es-module/test-esm-tla-dynamic-import-evaluating-async.mjs

@@ -0,0 +1,11 @@
+import '../common/index.mjs';
+import { spawnSyncAndAssert } from '../common/child_process.js';
+import * as fixtures from '../common/fixtures.mjs';
+
+// Regression test for https://github.com/nodejs/node/issues/66806
+spawnSyncAndAssert(process.execPath, [
+  fixtures.path('es-modules', 'tla', 'dynamic-import-evaluating-async', 'main.mjs'),
+], {
+  stdout: /^ok 2 2\n$/,
+  stderr: '',
+});

test/fixtures/es-modules/tla/dynamic-import-evaluating-async/a.mjs

@@ -0,0 +1,8 @@
+// Suspend so that main.mjs goes on to start evaluating b.mjs
+await import('./d.mjs');
+// b.mjs has been started but its body has not run yet
+const { x } = await import('./b.mjs');
+// b.mjs is now fully evaluated
+const again = await import('./b.mjs');
+if (again.x !== x) throw new Error(`expected ${x}, got ${again.x}`);
+export const a = () => x;

test/fixtures/es-modules/tla/dynamic-import-evaluating-async/b.mjs

@@ -0,0 +1,2 @@
+import { c } from './c.mjs';
+export const x = c + 1;

test/fixtures/es-modules/tla/dynamic-import-evaluating-async/c.mjs

@@ -0,0 +1,2 @@
+await new Promise((resolve) => setTimeout(resolve, 10));
+export const c = 1;

test/fixtures/es-modules/tla/dynamic-import-evaluating-async/d.mjs

@@ -0,0 +1 @@
+export const d = 0;

test/fixtures/es-modules/tla/dynamic-import-evaluating-async/main.mjs

@@ -0,0 +1,3 @@
+import { a } from './a.mjs';
+import { x } from './b.mjs';
+console.log('ok', a(), x);