Skip resolving files directly inside node_modules

or in @types. Although the node module resolution algorithm looks for
.js files there, they would never be there in correctly configured
node_modules. So it should be safe to skip *.ts, *.js, *.tsx, etc.

Also skips looking for files directly in node_modules/@types.

Fixes microsoft#52695

src/compiler/moduleNameResolver.ts

@@ -2868,7 +2868,7 @@ function loadModuleFromSpecificNodeModulesDirectory(extensions: Extensions, modu
 
     const loader: ResolutionKindSpecificLoader = (extensions, candidate, onlyRecordFailures, state) => {
         let pathAndExtension =
-            loadModuleFromFile(extensions, candidate, onlyRecordFailures, state) ||
+            rest && loadModuleFromFile(extensions, candidate, onlyRecordFailures, state) ||
             loadNodeModuleFromDirectoryWorker(
                 extensions,
                 candidate,

src/testRunner/unittests/moduleResolution.ts

@@ -262,7 +262,7 @@ describe("unittests:: moduleResolution:: Node module resolution - non-relative p
 
         function test(hasDirectoryExists: boolean) {
             const containingFile = { name: "/a/b/c/d/e.ts" };
-            const moduleFile = { name: "/a/b/node_modules/foo.ts" };
+            const moduleFile = { name: "/a/b/node_modules/foo/index.ts" };
             baselines.push(`Resolving "foo" from ${containingFile.name}${hasDirectoryExists ? "" : " with host that doesnt have directoryExists"}`);
             const resolution = ts.nodeModuleNameResolver("foo", containingFile.name, {}, createModuleResolutionHost(baselines, hasDirectoryExists, containingFile, moduleFile));
             baselines.push(`Resolution:: ${JSON.stringify(resolution, /*replacer*/ undefined, 2)}`);
@@ -278,7 +278,7 @@ describe("unittests:: moduleResolution:: Node module resolution - non-relative p
 
         function test(hasDirectoryExists: boolean) {
             const containingFile = { name: "/a/b/c/d/e.ts" };
-            const moduleFile = { name: "/a/b/node_modules/foo.d.ts" };
+            const moduleFile = { name: "/a/b/node_modules/foo/index.d.ts" };
             baselines.push(`Resolving "foo" from ${containingFile.name}${hasDirectoryExists ? "" : " with host that doesnt have directoryExists"}`);
             const resolution = ts.nodeModuleNameResolver("foo", containingFile.name, {}, createModuleResolutionHost(baselines, hasDirectoryExists, containingFile, moduleFile));
             baselines.push(`Resolution:: ${JSON.stringify(resolution, /*replacer*/ undefined, 2)}`);
@@ -672,7 +672,7 @@ describe("unittests:: moduleResolution:: baseUrl augmented module resolution", (
             const m2: File = { name: "/root/m2/index.d.ts" }; // load folder as module
             const m3: File = { name: "/root/m3/package.json", content: JSON.stringify({ typings: "dist/typings.d.ts" }) };
             const m3Typings: File = { name: "/root/m3/dist/typings.d.ts" };
-            const m4: File = { name: "/root/node_modules/m4.ts" }; // fallback to node
+            const m4: File = { name: "/root/node_modules/m4/index.ts" }; // fallback to node
 
             const options: ts.CompilerOptions = { moduleResolution: ts.ModuleResolutionKind.Node10, baseUrl: "/root" };
             const host = createModuleResolutionHost(baselines, hasDirectoryExists, main, m1, m2, m3, m3Typings, m4);
@@ -732,7 +732,7 @@ describe("unittests:: moduleResolution:: baseUrl augmented module resolution", (
             const file4Typings: File = { name: "/root/generated/folder2/file4/package.json", content: JSON.stringify({ typings: "dist/types.d.ts" }) };
             const file4: File = { name: "/root/generated/folder2/file4/dist/types.d.ts" }; // load file pointed by typings
             const file5: File = { name: "/root/someanotherfolder/file5/index.d.ts" }; // load remapped module from folder
-            const file6: File = { name: "/root/node_modules/file6.ts" }; // fallback to node
+            const file6: File = { name: "/root/node_modules/file6/index.ts" }; // fallback to node
             const host = createModuleResolutionHost(baselines, hasDirectoryExists, file1, file2, file3, file4, file4Typings, file5, file6);
 
             const options: ts.CompilerOptions = {
@@ -969,11 +969,6 @@ describe("unittests:: moduleResolution:: Type reference directive resolution: ",
     });
     it("Can be resolved from secondary location", () => {
         const baselines: string[] = [];
-        {
-            const f1 = { name: "/root/src/app.ts" };
-            const f2 = { name: "/root/node_modules/lib.d.ts" };
-            test(baselines, /*typesRoot*/"/root/src/types", /* typeDirective */"lib", f1, f2);
-        }
         {
             const f1 = { name: "/root/src/app.ts" };
             const f2 = { name: "/root/node_modules/lib/index.d.ts" };

src/testRunner/unittests/tscWatch/programUpdates.ts

@@ -389,7 +389,7 @@ export class A {
                 content: `import { T } from "module1";`
             };
             const nodeModuleFile: File = {
-                path: "/a/b/node_modules/module1.ts",
+                path: "/a/b/node_modules/module1/index.ts",
                 content: `export interface T {}`
             };
             const classicModuleFile: File = {

src/testRunner/unittests/tsserver/configuredProjects.ts

@@ -217,7 +217,7 @@ describe("unittests:: tsserver:: ConfiguredProjects", () => {
             content: `import { T } from "module1";`
         };
         const nodeModuleFile: File = {
-            path: "/a/b/node_modules/module1.ts",
+            path: "/a/b/node_modules/module1/index.ts",
             content: `export interface T {}`
         };
         const classicModuleFile: File = {

src/testRunner/unittests/tsserver/events/projectUpdatedInBackground.ts

@@ -439,7 +439,7 @@ describe("unittests:: tsserver:: events:: ProjectsUpdatedInBackground", () => {
                         content: 'import a from "file2"'
                     };
                     const file2: File = {
-                        path: rootFolder + "a/b/node_modules/file2.d.ts",
+                        path: rootFolder + "a/b/node_modules/file2/index.d.ts",
                         content: "export class a { }"
                     };
                     const file3: File = {

tests/baselines/reference/cachedModuleResolution1.js

@@ -1,13 +1,14 @@
 //// [tests/cases/compiler/cachedModuleResolution1.ts] ////
 
-//// [foo.d.ts]
+//// [index.d.ts]
 export declare let x: number
 
 //// [app.ts]
 import {x} from "foo";
 
 //// [lib.ts]
-import {x} from "foo";
+import {x} from "foo";
+
 
 //// [app.js]
 "use strict";

tests/baselines/reference/cachedModuleResolution1.symbols

@@ -1,6 +1,6 @@
-=== /a/b/node_modules/foo.d.ts ===
+=== /a/b/node_modules/foo/index.d.ts ===
 export declare let x: number
->x : Symbol(x, Decl(foo.d.ts, 0, 18))
+>x : Symbol(x, Decl(index.d.ts, 0, 18))
 
 === /a/b/c/d/e/app.ts ===
 import {x} from "foo";

tests/baselines/reference/cachedModuleResolution1.trace.json

@@ -5,14 +5,15 @@
     "Directory '/a/b/c/d/e/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/a/b/c/d/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/a/b/c/node_modules' does not exist, skipping all lookups in it.",
-    "File '/a/b/node_modules/foo.ts' does not exist.",
-    "File '/a/b/node_modules/foo.tsx' does not exist.",
-    "File '/a/b/node_modules/foo.d.ts' exists - use it as a name resolution result.",
-    "Resolving real path for '/a/b/node_modules/foo.d.ts', result '/a/b/node_modules/foo.d.ts'.",
-    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo.d.ts'. ========",
+    "File '/a/b/node_modules/foo/package.json' does not exist.",
+    "File '/a/b/node_modules/foo/index.ts' does not exist.",
+    "File '/a/b/node_modules/foo/index.tsx' does not exist.",
+    "File '/a/b/node_modules/foo/index.d.ts' exists - use it as a name resolution result.",
+    "Resolving real path for '/a/b/node_modules/foo/index.d.ts', result '/a/b/node_modules/foo/index.d.ts'.",
+    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo/index.d.ts'. ========",
     "======== Resolving module 'foo' from '/a/b/c/lib.ts'. ========",
     "Explicitly specified module resolution kind: 'Node10'.",
     "Loading module 'foo' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "Resolution for module 'foo' was found in cache from location '/a/b/c'.",
-    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo.d.ts'. ========"
+    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo/index.d.ts'. ========"
 ]

tests/baselines/reference/cachedModuleResolution1.types

@@ -1,4 +1,4 @@
-=== /a/b/node_modules/foo.d.ts ===
+=== /a/b/node_modules/foo/index.d.ts ===
 export declare let x: number
 >x : number
 

tests/baselines/reference/cachedModuleResolution2.js

@@ -1,6 +1,6 @@
 //// [tests/cases/compiler/cachedModuleResolution2.ts] ////
 
-//// [foo.d.ts]
+//// [index.d.ts]
 export declare let x: number
 
 //// [lib.ts]

tests/baselines/reference/cachedModuleResolution2.symbols

@@ -1,6 +1,6 @@
-=== /a/b/node_modules/foo.d.ts ===
+=== /a/b/node_modules/foo/index.d.ts ===
 export declare let x: number
->x : Symbol(x, Decl(foo.d.ts, 0, 18))
+>x : Symbol(x, Decl(index.d.ts, 0, 18))
 
 === /a/b/c/lib.ts ===
 import {x} from "foo";

tests/baselines/reference/cachedModuleResolution2.trace.json

@@ -3,16 +3,17 @@
     "Explicitly specified module resolution kind: 'Node10'.",
     "Loading module 'foo' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "Directory '/a/b/c/node_modules' does not exist, skipping all lookups in it.",
-    "File '/a/b/node_modules/foo.ts' does not exist.",
-    "File '/a/b/node_modules/foo.tsx' does not exist.",
-    "File '/a/b/node_modules/foo.d.ts' exists - use it as a name resolution result.",
-    "Resolving real path for '/a/b/node_modules/foo.d.ts', result '/a/b/node_modules/foo.d.ts'.",
-    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo.d.ts'. ========",
+    "File '/a/b/node_modules/foo/package.json' does not exist.",
+    "File '/a/b/node_modules/foo/index.ts' does not exist.",
+    "File '/a/b/node_modules/foo/index.tsx' does not exist.",
+    "File '/a/b/node_modules/foo/index.d.ts' exists - use it as a name resolution result.",
+    "Resolving real path for '/a/b/node_modules/foo/index.d.ts', result '/a/b/node_modules/foo/index.d.ts'.",
+    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo/index.d.ts'. ========",
     "======== Resolving module 'foo' from '/a/b/c/d/e/app.ts'. ========",
     "Explicitly specified module resolution kind: 'Node10'.",
     "Loading module 'foo' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "Directory '/a/b/c/d/e/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/a/b/c/d/node_modules' does not exist, skipping all lookups in it.",
     "Resolution for module 'foo' was found in cache from location '/a/b/c'.",
-    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo.d.ts'. ========"
+    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo/index.d.ts'. ========"
 ]

tests/baselines/reference/cachedModuleResolution2.types

@@ -1,4 +1,4 @@
-=== /a/b/node_modules/foo.d.ts ===
+=== /a/b/node_modules/foo/index.d.ts ===
 export declare let x: number
 >x : number
 

tests/baselines/reference/cachedModuleResolution5.js

@@ -1,13 +1,14 @@
 //// [tests/cases/compiler/cachedModuleResolution5.ts] ////
 
-//// [foo.d.ts]
+//// [index.d.ts]
 export declare let x: number
 
 //// [app.ts]
 import {x} from "foo";
 
 //// [lib.ts]
-import {x} from "foo";
+import {x} from "foo";
+
 
 //// [app.js]
 "use strict";

tests/baselines/reference/cachedModuleResolution5.symbols

@@ -1,6 +1,6 @@
-=== /a/b/node_modules/foo.d.ts ===
+=== /a/b/node_modules/foo/index.d.ts ===
 export declare let x: number
->x : Symbol(x, Decl(foo.d.ts, 0, 18))
+>x : Symbol(x, Decl(index.d.ts, 0, 18))
 
 === /a/b/c/d/e/app.ts ===
 import {x} from "foo";

tests/baselines/reference/cachedModuleResolution5.trace.json

@@ -5,14 +5,15 @@
     "Directory '/a/b/c/d/e/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/a/b/c/d/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/a/b/c/node_modules' does not exist, skipping all lookups in it.",
-    "File '/a/b/node_modules/foo.ts' does not exist.",
-    "File '/a/b/node_modules/foo.tsx' does not exist.",
-    "File '/a/b/node_modules/foo.d.ts' exists - use it as a name resolution result.",
-    "Resolving real path for '/a/b/node_modules/foo.d.ts', result '/a/b/node_modules/foo.d.ts'.",
-    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo.d.ts'. ========",
+    "File '/a/b/node_modules/foo/package.json' does not exist.",
+    "File '/a/b/node_modules/foo/index.ts' does not exist.",
+    "File '/a/b/node_modules/foo/index.tsx' does not exist.",
+    "File '/a/b/node_modules/foo/index.d.ts' exists - use it as a name resolution result.",
+    "Resolving real path for '/a/b/node_modules/foo/index.d.ts', result '/a/b/node_modules/foo/index.d.ts'.",
+    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo/index.d.ts'. ========",
     "======== Resolving module 'foo' from '/a/b/lib.ts'. ========",
     "Explicitly specified module resolution kind: 'Node10'.",
     "Loading module 'foo' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "Resolution for module 'foo' was found in cache from location '/a/b'.",
-    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo.d.ts'. ========"
+    "======== Module name 'foo' was successfully resolved to '/a/b/node_modules/foo/index.d.ts'. ========"
 ]

tests/baselines/reference/cachedModuleResolution5.types

@@ -1,4 +1,4 @@
-=== /a/b/node_modules/foo.d.ts ===
+=== /a/b/node_modules/foo/index.d.ts ===
 export declare let x: number
 >x : number
 

tests/baselines/reference/customConditions(resolvepackagejsonexports=false).trace.json

@@ -4,9 +4,6 @@
     "File '/package.json' does not exist.",
     "Loading module 'lodash' from 'node_modules' folder, target file types: TypeScript, JavaScript, Declaration, JSON.",
     "Found 'package.json' at '/node_modules/lodash/package.json'.",
-    "File '/node_modules/lodash.ts' does not exist.",
-    "File '/node_modules/lodash.tsx' does not exist.",
-    "File '/node_modules/lodash.d.ts' does not exist.",
     "'package.json' does not have a 'typesVersions' field.",
     "'package.json' does not have a 'typings' field.",
     "'package.json' does not have a 'types' field.",

tests/baselines/reference/duplicatePackage_relativeImportWithinPackage.trace.json

@@ -13,9 +13,6 @@
     "Module resolution kind is not specified, using 'Node10'.",
     "Loading module 'a' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "File '/node_modules/a/package.json' does not exist.",
-    "File '/node_modules/a.ts' does not exist.",
-    "File '/node_modules/a.tsx' does not exist.",
-    "File '/node_modules/a.d.ts' does not exist.",
     "File '/node_modules/a/index.ts' does not exist.",
     "File '/node_modules/a/index.tsx' does not exist.",
     "File '/node_modules/a/index.d.ts' exists - use it as a name resolution result.",
@@ -33,9 +30,6 @@
     "Module resolution kind is not specified, using 'Node10'.",
     "Loading module 'foo' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "Found 'package.json' at '/node_modules/a/node_modules/foo/package.json'.",
-    "File '/node_modules/a/node_modules/foo.ts' does not exist.",
-    "File '/node_modules/a/node_modules/foo.tsx' does not exist.",
-    "File '/node_modules/a/node_modules/foo.d.ts' does not exist.",
     "'package.json' does not have a 'typesVersions' field.",
     "'package.json' does not have a 'typings' field.",
     "'package.json' does not have a 'types' field.",

tests/baselines/reference/duplicatePackage_relativeImportWithinPackage_scoped.trace.json

@@ -13,9 +13,6 @@
     "Module resolution kind is not specified, using 'Node10'.",
     "Loading module 'a' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "File '/node_modules/a/package.json' does not exist.",
-    "File '/node_modules/a.ts' does not exist.",
-    "File '/node_modules/a.tsx' does not exist.",
-    "File '/node_modules/a.d.ts' does not exist.",
     "File '/node_modules/a/index.ts' does not exist.",
     "File '/node_modules/a/index.tsx' does not exist.",
     "File '/node_modules/a/index.d.ts' exists - use it as a name resolution result.",
@@ -33,9 +30,6 @@
     "Module resolution kind is not specified, using 'Node10'.",
     "Loading module '@foo/bar' from 'node_modules' folder, target file types: TypeScript, Declaration.",
     "Found 'package.json' at '/node_modules/a/node_modules/@foo/bar/package.json'.",
-    "File '/node_modules/a/node_modules/@foo/bar.ts' does not exist.",
-    "File '/node_modules/a/node_modules/@foo/bar.tsx' does not exist.",
-    "File '/node_modules/a/node_modules/@foo/bar.d.ts' does not exist.",
     "'package.json' does not have a 'typesVersions' field.",
     "'package.json' does not have a 'typings' field.",
     "'package.json' does not have a 'types' field.",

tests/baselines/reference/importShouldNotBeElidedInDeclarationEmit.js

@@ -1,6 +1,6 @@
 //// [tests/cases/compiler/importShouldNotBeElidedInDeclarationEmit.ts] ////
 
-//// [umd.d.ts]
+//// [index.d.ts]
 export as namespace UMD;
 
 export type Thing = {

tests/baselines/reference/importShouldNotBeElidedInDeclarationEmit.symbols

@@ -1,17 +1,17 @@
-=== tests/cases/compiler/node_modules/umd.d.ts ===
+=== tests/cases/compiler/node_modules/umd/index.d.ts ===
 export as namespace UMD;
->UMD : Symbol(UMD, Decl(umd.d.ts, 0, 0))
+>UMD : Symbol(UMD, Decl(index.d.ts, 0, 0))
 
 export type Thing = {
->Thing : Symbol(Thing, Decl(umd.d.ts, 0, 24))
+>Thing : Symbol(Thing, Decl(index.d.ts, 0, 24))
 
     a: number;
->a : Symbol(a, Decl(umd.d.ts, 2, 21))
+>a : Symbol(a, Decl(index.d.ts, 2, 21))
 }
 
 export declare function makeThing(): Thing;
->makeThing : Symbol(makeThing, Decl(umd.d.ts, 4, 1))
->Thing : Symbol(Thing, Decl(umd.d.ts, 0, 24))
+>makeThing : Symbol(makeThing, Decl(index.d.ts, 4, 1))
+>Thing : Symbol(Thing, Decl(index.d.ts, 0, 24))
 
 === tests/cases/compiler/index.ts ===
 import { makeThing } from "umd";

tests/baselines/reference/importShouldNotBeElidedInDeclarationEmit.types

@@ -1,6 +1,6 @@
-=== tests/cases/compiler/node_modules/umd.d.ts ===
+=== tests/cases/compiler/node_modules/umd/index.d.ts ===
 export as namespace UMD;
->UMD : typeof import("tests/cases/compiler/node_modules/umd")
+>UMD : typeof import("tests/cases/compiler/node_modules/umd/index")
 
 export type Thing = {
 >Thing : { a: number; }
@@ -14,10 +14,10 @@ export declare function makeThing(): Thing;
 
 === tests/cases/compiler/index.ts ===
 import { makeThing } from "umd";
->makeThing : () => import("tests/cases/compiler/node_modules/umd").Thing
+>makeThing : () => import("tests/cases/compiler/node_modules/umd/index").Thing
 
 export const thing = makeThing();
->thing : import("tests/cases/compiler/node_modules/umd").Thing
->makeThing() : import("tests/cases/compiler/node_modules/umd").Thing
->makeThing : () => import("tests/cases/compiler/node_modules/umd").Thing
+>thing : import("tests/cases/compiler/node_modules/umd/index").Thing
+>makeThing() : import("tests/cases/compiler/node_modules/umd/index").Thing
+>makeThing : () => import("tests/cases/compiler/node_modules/umd/index").Thing
 

tests/baselines/reference/library-reference-11.trace.json

@@ -4,7 +4,6 @@
     "Looking up in 'node_modules' folder, initial location '/a/b'.",
     "Directory '/a/b/node_modules' does not exist, skipping all lookups in it.",
     "Found 'package.json' at '/a/node_modules/jquery/package.json'.",
-    "File '/a/node_modules/jquery.d.ts' does not exist.",
     "'package.json' does not have a 'typesVersions' field.",
     "'package.json' has 'typings' field 'jquery.d.ts' that references '/a/node_modules/jquery/jquery.d.ts'.",
     "File '/a/node_modules/jquery/jquery.d.ts' exists - use it as a name resolution result.",

tests/baselines/reference/library-reference-12.trace.json

@@ -4,7 +4,6 @@
     "Looking up in 'node_modules' folder, initial location '/a/b'.",
     "Directory '/a/b/node_modules' does not exist, skipping all lookups in it.",
     "Found 'package.json' at '/a/node_modules/jquery/package.json'.",
-    "File '/a/node_modules/jquery.d.ts' does not exist.",
     "'package.json' does not have a 'typesVersions' field.",
     "'package.json' does not have a 'typings' field.",
     "'package.json' has 'types' field 'dist/jquery.d.ts' that references '/a/node_modules/jquery/dist/jquery.d.ts'.",

tests/baselines/reference/library-reference-3.trace.json

@@ -3,7 +3,6 @@
     "Root directory cannot be determined, skipping primary search paths.",
     "Looking up in 'node_modules' folder, initial location '/src'.",
     "File '/src/node_modules/jquery/package.json' does not exist.",
-    "File '/src/node_modules/jquery.d.ts' does not exist.",
     "File '/src/node_modules/jquery/index.d.ts' exists - use it as a name resolution result.",
     "Resolving real path for '/src/node_modules/jquery/index.d.ts', result '/src/node_modules/jquery/index.d.ts'.",
     "======== Type reference directive 'jquery' was successfully resolved to '/src/node_modules/jquery/index.d.ts', primary: false. ========"