esm: modify resolution order for specifier flag

MylesBorins · targos · commit 94ac44f3fcc2 · 2019-11-10T14:50:11.000+01:00
Currently `--es-module-specifier-resolution=node` has an alternative resolution order than the default in common.js, this causes inconsistencies. As discussed in @nodejs/modules we want to preserve resolution order between implementations. PR-URL: #29974 Reviewed-By: Jan Krems <jan.krems@gmail.com> Reviewed-By: Guy Bedford <guybedford@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/lib/internal/modules/esm/default_resolve.js b/lib/internal/modules/esm/default_resolve.js
@@ -9,6 +9,8 @@ const { getOptionValue } = require('internal/options');
 const preserveSymlinks = getOptionValue('--preserve-symlinks');
 const preserveSymlinksMain = getOptionValue('--preserve-symlinks-main');
 const experimentalJsonModules = getOptionValue('--experimental-json-modules');
+const esModuleSpecifierResolution =
+ getOptionValue('--es-module-specifier-resolution');
 const typeFlag = getOptionValue('--input-type');
 const experimentalWasmModules = getOptionValue('--experimental-wasm-modules');
 const { resolve: moduleWrapResolve,
@@ -110,6 +112,8 @@ function resolve(specifier, parentURL) {
 if (!format) {
 if (isMain)
 format = type === TYPE_MODULE ? 'module' : 'commonjs';
+ else if (esModuleSpecifierResolution === 'node')
+ format = 'commonjs';
 else
 throw new ERR_UNKNOWN_FILE_EXTENSION(fileURLToPath(url));
 }
diff --git a/src/module_wrap.cc b/src/module_wrap.cc
@@ -48,11 +48,10 @@ using v8::Undefined;
 using v8::Value;
 
 static const char* const EXTENSIONS[] = {
- ".mjs",
- ".cjs",
 ".js",
 ".json",
- ".node"
+ ".node",
+ ".mjs"
 };
 
 ModuleWrap::ModuleWrap(Environment* env,
diff --git a/test/es-module/test-esm-specifiers.mjs b/test/es-module/test-esm-specifiers.mjs
@@ -1,5 +1,5 @@
 // Flags: --experimental-modules --es-module-specifier-resolution=node
-import { mustNotCall } from '../common';
+import { mustNotCall } from '../common/index.mjs';
 import assert from 'assert';
 
 // commonJS index.js
@@ -14,8 +14,8 @@ assert.strictEqual(commonjs, 'commonjs');
 assert.strictEqual(module, 'module');
 assert.strictEqual(success, 'success');
 assert.strictEqual(explicit, 'esm');
-assert.strictEqual(implicit, 'esm');
-assert.strictEqual(implicitModule, 'esm');
+assert.strictEqual(implicit, 'cjs');
+assert.strictEqual(implicitModule, 'cjs');
 
 async function main() {
 try {
diff --git a/test/fixtures/es-module-specifiers/node_modules/implicit-main-type-module/entry.js b/test/fixtures/es-module-specifiers/node_modules/implicit-main-type-module/entry.js

-Original file line number
+Diff line change
 constpreserveSymlinks=getOptionValue('--preserve-symlinks');
 constpreserveSymlinksMain=getOptionValue('--preserve-symlinks-main');
 constexperimentalJsonModules=getOptionValue('--experimental-json-modules');
 +constesModuleSpecifierResolution=
 +getOptionValue('--es-module-specifier-resolution');
 consttypeFlag=getOptionValue('--input-type');
 constexperimentalWasmModules=getOptionValue('--experimental-wasm-modules');
 const{resolve: moduleWrapResolve,
 if(!format){
 if(isMain)
 format=type===TYPE_MODULE ? 'module' : 'commonjs';
 +elseif(esModuleSpecifierResolution==='node')
 +format='commonjs';
 else
 thrownewERR_UNKNOWN_FILE_EXTENSION(fileURLToPath(url));
+}
-Original file line number
+Diff line change
@@ @@ -1,5 +1,5 @@ @@
 // Flags: --experimental-modules --es-module-specifier-resolution=node
 -import{mustNotCall}from'../common';
 +import{mustNotCall}from'../common/index.mjs';
 importassertfrom'assert';
 // commonJS index.js
 assert.strictEqual(module,'module');
 assert.strictEqual(success,'success');
 assert.strictEqual(explicit,'esm');
 -assert.strictEqual(implicit,'esm');
 -assert.strictEqual(implicitModule,'esm');
 +assert.strictEqual(implicit,'cjs');
 +assert.strictEqual(implicitModule,'cjs');
 asyncfunctionmain(){
 try{