module: add dynamic file-specific ESM warnings

PR-URL: #56628
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: mertcanaltin

src/node_contextify.cc

@@ -1702,13 +1702,19 @@ static MaybeLocal<Function> CompileFunctionForCJSLoader(
 return scope.Escape(fn);
 }
 
+static std::string GetRequireEsmWarning(Local<String> filename) {
+ Isolate* isolate = Isolate::GetCurrent();
+ Utf8Value filename_utf8(isolate, filename);
+
+ std::string warning_message =
+"Failed to load the ES module: " + filename_utf8.ToString() +
+". Make sure to set \"type\": \"module\" in the nearest package.json "
+"file "
+"or use the .mjs extension.";
+return warning_message;
+}
+
 staticbool warned_about_require_esm = false;
-// TODO(joyeecheung): this was copied from the warning previously emitted in the
-// JS land, but it's not very helpful. There should be specific information
-// about which file or which package.json to update.
-constchar* require_esm_warning =
-"To load an ES module, set \"type\": \"module\" in the package.json or use "
-"the .mjs extension.";
 
 staticboolShouldRetryAsESM(Realm* realm,
  Local<String> message,
@@ -1794,8 +1800,8 @@ static void CompileFunctionForCJSLoader(
 // This needs to call process.emit('warning') in JS which can throw if
 // the user listener throws. In that case, don't try to throw the syntax
 // error.
-should_throw =
-ProcessEmitWarningSync(env, require_esm_warning).IsJust();
+std::string warning_message = GetRequireEsmWarning(filename);
+should_throw = ProcessEmitWarningSync(env, warning_message).IsJust();
  }
 if (should_throw) {
  isolate->ThrowException(cjs_exception);

src/node_process_events.cc

@@ -13,6 +13,7 @@ using v8::Just;
 using v8::Local;
 using v8::Maybe;
 using v8::MaybeLocal;
+using v8::NewStringType;
 using v8::Nothing;
 using v8::Object;
 using v8::String;
@@ -21,7 +22,14 @@ using v8::Value;
 Maybe<bool> ProcessEmitWarningSync(Environment* env, std::string_view message) {
  Isolate* isolate = env->isolate();
  Local<Context> context = env->context();
- Local<String> message_string = OneByteString(isolate, message);
+ Local<String> message_string;
+if (!String::NewFromUtf8(isolate,
+ message.data(),
+ NewStringType::kNormal,
+static_cast<int>(message.size()))
+ .ToLocal(&message_string)) {
+return Nothing<bool>();
+ }
 
  Local<Value> argv[] = {message_string};
  Local<Function> emit_function = env->process_emit_warning_sync();

test/es-module/test-esm-cjs-load-error-note.mjs

@@ -4,11 +4,10 @@ import assert from 'node:assert';
 import{execPath}from'node:process';
 import{describe,it}from'node:test';
 
-
 // Expect note to be included in the error output
 // Don't match the following sentence because it can change as features are
 // added.
-constexpectedNote='Warning: To load an ES module';
+constexpectedNote='Failed to load the ES module';
 
 constmustIncludeMessage={
 getMessage: (stderr)=>`${expectedNote} not found in ${stderr}`,

test/es-module/test-esm-long-path-win.js

@@ -182,7 +182,7 @@ describe('long path on Windows', () => {
 fs.writeFileSync(cjsIndexJSPath,'import fs from "node:fs/promises";');
 const{ code, signal, stderr }=awaitspawnPromisified(execPath,[cjsIndexJSPath]);
 
-assert.ok(stderr.includes('Warning: To load an ES module'));
+assert.ok(stderr.includes('Failed to load the ES module'));
 assert.strictEqual(code,1);
 assert.strictEqual(signal,null);
 });

test/es-module/test-typescript-commonjs.mjs

@@ -1,6 +1,6 @@
 import{skip,spawnPromisified}from'../common/index.mjs';
 import*asfixturesfrom'../common/fixtures.mjs';
-import{match,strictEqual}from'node:assert';
+importassert,{match,strictEqual}from'node:assert';
 import{test}from'node:test';
 
 if(!process.config.variables.node_use_amaro)skip('Requires Amaro');
@@ -59,13 +59,35 @@ test('require a .ts file with implicit extension fails', async () => {
 });
 
 test('expect failure of an .mts file with CommonJS syntax',async()=>{
-constresult=awaitspawnPromisified(process.execPath,[
-fixtures.path('typescript/cts/test-cts-but-module-syntax.cts'),
-]);
-
-strictEqual(result.stdout,'');
-match(result.stderr,/ToloadanESmodule,set"type":"module"inthepackage\.jsonorusethe\.mjsextension\./);
-strictEqual(result.code,1);
+consttestFilePath=fixtures.path(
+'typescript/cts/test-cts-but-module-syntax.cts'
+);
+constresult=awaitspawnPromisified(process.execPath,[testFilePath]);
+
+assert.strictEqual(result.stdout,'');
+
+constexpectedWarning=`Failed to load the ES module: ${testFilePath}. Make sure to set "type": "module" in the nearest package.json file or use the .mjs extension.`;
+
+try{
+assert.ok(
+result.stderr.includes(expectedWarning),
+`Expected stderr to include: ${expectedWarning}`
+);
+}catch(e){
+if(e?.code==='ERR_ASSERTION'){
+assert.match(
+result.stderr,
+/FailedtoloadtheESmodule:.*test-cts-but-module-syntax\.cts/
+);
+e.expected=expectedWarning;
+e.actual=result.stderr;
+e.operator='includes';
+}
+throwe;
+}
+
+
+assert.strictEqual(result.code,1);
 });
 
 test('execute a .cts file importing a .cts file',async()=>{