lib,test: improves ERR_REQUIRE_ESM message

PR-URL: https://github.com/nodejs/node/pull/30694
Fixes: https://github.com/nodejs/node/issues/30599
Reviewed-By: Guy Bedford <guybedford@gmail.com>

2 files changed, 11 insertions, 4 deletions

diff --git a/test/es-module/test-cjs-esm-warn.js b/test/es-module/test-cjs-esm-warn.js
index b1b2e7f434..b800a47d05 100644
--- a/test/es-module/test-cjs-esm-warn.js
+++ b/test/es-module/test-cjs-esm-warn.js
@@ -26,15 +26,19 @@ child.on('close', common.mustCall((code, signal) => {
   assert.strictEqual(code, 1);
   assert.strictEqual(signal, null);
 
-  assert.ok(stderr.startsWith(`(node:${child.pid}) Warning: ` +
-    'require() of ES modules is not supported.\nrequire() of ' +
+  assert.ok(stderr.indexOf(
+    `Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: ${required}` +
+    '\nrequire() of ES modules is not supported.\nrequire() of ' +
     `${required} from ${requiring} ` +
     'is an ES module file as it is a .js file whose nearest parent ' +
     'package.json contains "type": "module" which defines all .js ' +
     'files in that package scope as ES modules.\nInstead rename ' +
     `${basename} to end in .cjs, change the requiring code to use ` +
     'import(), or remove "type": "module" from ' +
-    `${pjson}.\n`));
+    `${pjson}.\n`) !== -1);
   assert.ok(stderr.indexOf(
     'Error [ERR_REQUIRE_ESM]: Must use import to load ES Module') !== -1);
+
+  assert.strictEqual(
+    stderr.match(/Must use import to load ES Module/g).length, 1);
 }));
diff --git a/test/es-module/test-esm-type-flag-errors.js b/test/es-module/test-esm-type-flag-errors.js
index 5d19cedd84..e0dedc16ca 100644
--- a/test/es-module/test-esm-type-flag-errors.js
+++ b/test/es-module/test-esm-type-flag-errors.js
@@ -27,7 +27,10 @@ try {
   require('../fixtures/es-modules/package-type-module/index.js');
   assert.fail('Expected CJS to fail loading from type: module package.');
 } catch (e) {
-  assert(e.toString().match(/Error \[ERR_REQUIRE_ESM\]: Must use import to load ES Module:/));
+  assert.strictEqual(e.name, 'Error');
+  assert.strictEqual(e.code, 'ERR_REQUIRE_ESM');
+  assert(e.toString().match(/Must use import to load ES Module/g));
+  assert(e.message.match(/Must use import to load ES Module/g));
 }
 
 function expect(opt = '', inputFile, want, wantsError = false) {