Use loader with extension substitution for package.json main, types, typesVersions (#57261)

Author: andrewbranch

src/compiler/diagnosticMessages.json

@@ -4723,10 +4723,6 @@
         "category": "Message",
         "code": 6080
     },
-    "File '{0}' has an unsupported extension, so skipping it.": {
-        "category": "Message",
-        "code": 6081
-    },
     "Only 'amd' and 'system' modules are supported alongside --{0}.": {
         "category": "Error",
         "code": 6082

src/compiler/moduleNameResolver.ts

@@ -2090,7 +2090,6 @@ function loadModuleFromFileNoImplicitExtensions(extensions: Extensions, candidat
 /**
  * This function is only ever called with paths written in package.json files - never
  * module specifiers written in source files - and so it always allows the
-
  * candidate to end with a TS extension (but will also try substituting a JS extension for a TS extension).
  */
 function loadFileNameFromPackageJsonField(extensions: Extensions, candidate: string, onlyRecordFailures: boolean, state: ModuleResolutionState): PathAndExtension | undefined {
@@ -2459,15 +2458,9 @@ function loadNodeModuleFromDirectoryWorker(extensions: Extensions, candidate: st
     }
 
     const loader: ResolutionKindSpecificLoader = (extensions, candidate, onlyRecordFailures, state) => {
-        const fromFile = tryFile(candidate, onlyRecordFailures, state);
+        const fromFile = loadFileNameFromPackageJsonField(extensions, candidate, onlyRecordFailures, state);
         if (fromFile) {
-            const resolved = resolvedIfExtensionMatches(extensions, fromFile);
-            if (resolved) {
-                return noPackageId(resolved);
-            }
-            if (state.traceEnabled) {
-                trace(state.host, Diagnostics.File_0_has_an_unsupported_extension_so_skipping_it, fromFile);
-            }
+            return noPackageId(fromFile);
         }
 
         // Even if extensions is DtsOnly, we can still look up a .ts file as a result of package.json "types"
@@ -2514,12 +2507,6 @@ function loadNodeModuleFromDirectoryWorker(extensions: Extensions, candidate: st
     }
 }
 
-/** Resolve from an arbitrarily specified file. Return `undefined` if it has an unsupported extension. */
-function resolvedIfExtensionMatches(extensions: Extensions, path: string, resolvedUsingTsExtension?: boolean): PathAndExtension | undefined {
-    const ext = tryGetExtensionFromPath(path);
-    return ext !== undefined && extensionIsOk(extensions, ext) ? { path, ext, resolvedUsingTsExtension } : undefined;
-}
-
 /** True if `extension` is one of the supported `extensions`. */
 function extensionIsOk(extensions: Extensions, extension: string): boolean {
     return extensions & Extensions.JavaScript && (extension === Extension.Js || extension === Extension.Jsx || extension === Extension.Mjs || extension === Extension.Cjs)

tests/baselines/reference/bundlerDirectoryModule(moduleresolution=bundler).errors.txt

@@ -0,0 +1,20 @@
+error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserve' or to 'es2015' or later.
+error TS5109: Option 'moduleResolution' must be set to 'NodeNext' (or left unspecified) when option 'module' is set to 'NodeNext'.
+
+
+!!! error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserve' or to 'es2015' or later.
+!!! error TS5109: Option 'moduleResolution' must be set to 'NodeNext' (or left unspecified) when option 'module' is set to 'NodeNext'.
+==== /app/test.ts (0 errors) ====
+    import { test } from '../lib';
+    
+==== /lib/package.json (0 errors) ====
+    {
+      "main": "./cjs/index.js"
+    }
+    
+==== /lib/cjs/index.js (0 errors) ====
+    export function test() {}
+    
+==== /lib/cjs/index.d.ts (0 errors) ====
+    export function test(): void;
+    

tests/baselines/reference/bundlerDirectoryModule(moduleresolution=bundler).trace.json

@@ -0,0 +1,99 @@
+[
+    "======== Resolving module '../lib' from '/app/test.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Resolving in CJS mode with conditions 'import', 'types'.",
+    "Loading module as file / folder, candidate module location '/lib', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/lib.ts' does not exist.",
+    "File '/lib.tsx' does not exist.",
+    "File '/lib.d.ts' does not exist.",
+    "File '/lib.js' does not exist.",
+    "File '/lib.jsx' does not exist.",
+    "Found 'package.json' at '/lib/package.json'.",
+    "'package.json' does not have a 'typesVersions' field.",
+    "'package.json' does not have a 'typings' field.",
+    "'package.json' does not have a 'types' field.",
+    "'package.json' has 'main' field './cjs/index.js' that references '/lib/cjs/index.js'.",
+    "File name '/lib/cjs/index.js' has a '.js' extension - stripping it.",
+    "File '/lib/cjs/index.ts' does not exist.",
+    "File '/lib/cjs/index.tsx' does not exist.",
+    "File '/lib/cjs/index.d.ts' exists - use it as a name resolution result.",
+    "======== Module name '../lib' was successfully resolved to '/lib/cjs/index.d.ts'. ========",
+    "======== Resolving module '@typescript/lib-es5' from '/.src/__lib_node_modules_lookup_lib.es5.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-es5'",
+    "Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-es5' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-decorators' from '/.src/__lib_node_modules_lookup_lib.decorators.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators'",
+    "Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-decorators' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-decorators/legacy' from '/.src/__lib_node_modules_lookup_lib.decorators.legacy.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-decorators/legacy'",
+    "Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-decorators/legacy' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-dom' from '/.src/__lib_node_modules_lookup_lib.dom.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-dom'",
+    "Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-dom' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-webworker/importscripts' from '/.src/__lib_node_modules_lookup_lib.webworker.importscripts.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-webworker/importscripts'",
+    "Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-webworker/importscripts' was not resolved. ========",
+    "======== Resolving module '@typescript/lib-scripthost' from '/.src/__lib_node_modules_lookup_lib.scripthost.d.ts__.ts'. ========",
+    "Explicitly specified module resolution kind: 'Node10'.",
+    "Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: TypeScript, Declaration.",
+    "Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "Scoped package detected, looking in 'typescript__lib-scripthost'",
+    "Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: JavaScript.",
+    "Searching all ancestor node_modules directories for fallback extensions: JavaScript.",
+    "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
+    "Directory '/node_modules' does not exist, skipping all lookups in it.",
+    "======== Module name '@typescript/lib-scripthost' was not resolved. ========"
+]