module: include module information in require(esm) warning

When emitting the experimental warning for `require(esm)`, include information about the parent module and the module being require()-d to help users locate and update them. PR-URL: #55397 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Stephen Belanger <[email protected]> Reviewed-By: Chemi Atlow <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]>

Author: joyeecheung

lib/internal/modules/cjs/loader.js

@@ -1369,11 +1369,31 @@ function loadESMFromCJS(mod, filename){
 // ESM won't be accessible via process.mainModule.
 setOwnProperty(process,'mainModule',undefined);
 }else{
-emitExperimentalWarning('Support for loading ES Module in require()');
+constparent=mod[kModuleParent];
+letmessagePrefix;
+if(parent){
+// In the case of the module calling `require()`, it's more useful to know its absolute path.
+letfrom=parent.filename||parent.id;
+// In the case of the module being require()d, it's more useful to know the id passed into require().
+constto=mod.id||mod.filename;
+if(from==='internal/preload'){
+from='--require';
+}elseif(from==='<repl>'){
+from='The REPL';
+}elseif(from==='.'){
+from='The entry point';
+}else{
+from&&=`CommonJS module ${from}`;
+}
+if(from&&to){
+messagePrefix=`${from} is loading ES Module ${to} using require().\n`;
+}
+}
+emitExperimentalWarning('Support for loading ES Module in require()',messagePrefix);
 const{
  wrap,
  namespace,
-}=cascadedLoader.importSyncForRequire(mod,filename,source,isMain,mod[kModuleParent]);
+}=cascadedLoader.importSyncForRequire(mod,filename,source,isMain,parent);
 // Tooling in the ecosystem have been using the __esModule property to recognize
 // transpiled ESM in consuming code. For example, a 'log' package written in ESM:
 //

lib/internal/util.js

@@ -266,10 +266,13 @@ function slowCases(enc){
 }
 }
 
-functionemitExperimentalWarning(feature){
+functionemitExperimentalWarning(feature,messagePrefix){
 if(experimentalWarnings.has(feature))return;
-constmsg=`${feature} is an experimental feature and might change at any time`;
 experimentalWarnings.add(feature);
+letmsg=`${feature} is an experimental feature and might change at any time`;
+if(messagePrefix){
+msg=messagePrefix+msg;
+}
 process.emitWarning(msg,'ExperimentalWarning');
 }
 

test/es-module/test-require-module-preload.js

@@ -4,11 +4,9 @@ require('../common');
 const{ spawnSyncAndAssert }=require('../common/child_process');
 const{ fixturesDir }=require('../common/fixtures');
 
-constwarningRE=/ExperimentalWarning:SupportforloadingESModuleinrequire/;
 functiontestPreload(preloadFlag){
 // The warning is only emitted when ESM is loaded by --require.
-conststderr=preloadFlag!=='--import' ? warningRE : undefined;
-
+constisRequire=preloadFlag==='--require';
 // Test named exports.
 {
 spawnSyncAndAssert(
@@ -24,7 +22,8 @@ function testPreload(preloadFlag){
 },
 {
 stdout: 'A',
- stderr,
+stderr: isRequire ?
+/ExperimentalWarning:--requireisloadingESModule.*module-named-exports\.mjsusingrequire/ : undefined,
 trim: true,
 }
 );
@@ -44,7 +43,8 @@ function testPreload(preloadFlag){
 cwd: fixturesDir
 },
 {
- stderr,
+stderr: isRequire ?
+/ExperimentalWarning:--requireisloadingESModule.*import-esm\.mjsusingrequire/ : undefined,
 stdout: /^world\s+A$/,
 trim: true,
 }
@@ -66,7 +66,8 @@ function testPreload(preloadFlag){
 },
 {
 stdout: /^ok\s+A$/,
- stderr,
+stderr: isRequire ?
+/ExperimentalWarning:--requireisloadingESModule.*cjs-exports\.mjsusingrequire/ : undefined,
 trim: true,
 }
 );
@@ -89,7 +90,8 @@ function testPreload(preloadFlag){
 },
 {
 stdout: /^world\s+A$/,
- stderr,
+stderr: isRequire ?
+/ExperimentalWarning:--requireisloadingESModule.*require-cjs\.mjsusingrequire/ : undefined,
 trim: true,
 }
 );
@@ -115,7 +117,7 @@ testPreload('--import');
 },
 {
 stdout: /^package-type-module\s+A$/,
-stderr: warningRE,
+stderr: /ExperimentalWarning:--requireisloadingESModule.*package-type-module[\\/]index\.jsusingrequire/,
 trim: true,
 }
 );

test/es-module/test-require-module.js

@@ -3,9 +3,13 @@
 
 constcommon=require('../common');
 constassert=require('assert');
+constpath=require('path');
 
+// Only the first load will trigger the warning.
 common.expectWarning(
 'ExperimentalWarning',
+`CommonJS module ${__filename} is loading ES Module `+
+`${path.resolve(__dirname,'../fixtures/es-module-loaders/module-named-exports.mjs')} using require().\n`+
 'Support for loading ES Module in require() is an experimental feature '+
 'and might change at any time'
 );