Support @types module resolution from scoped packages

src/compiler/diagnosticMessages.json

@@ -3177,6 +3177,10 @@
         "category": "Message",
         "code": 6181
     },
+    "Scoped package detected, looking in '{0}'": {
+        "category": "Message",
+        "code": "6182"
+    },
 
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",

src/compiler/moduleNameResolver.ts

@@ -954,10 +954,25 @@ namespace ts {
                 }
                 nodeModulesAtTypesExists = false;
             }
-            return loadModuleFromNodeModulesFolder(Extensions.DtsOnly, moduleName, nodeModulesAtTypes, nodeModulesAtTypesExists, failedLookupLocations, state);
+            return loadModuleFromNodeModulesFolder(Extensions.DtsOnly, mangleScopedPackage(moduleName, state), nodeModulesAtTypes, nodeModulesAtTypesExists, failedLookupLocations, state);
         }
     }
 
+    /** For a scoped package, we must look in `@types/foo__bar` instead of `@types/@foo/bar`. */
+    function mangleScopedPackage(moduleName: string, state: ModuleResolutionState): string {
+        if (startsWith(moduleName, "@")) {
+            const replaceSlash = moduleName.replace(ts.directorySeparator, "__");
+            if (replaceSlash !== moduleName) {
+                const mangled = replaceSlash.slice(1); // Take off the "@"
+                if (state.traceEnabled) {
+                    trace(state.host, Diagnostics.Scoped_package_detected_looking_in_0, mangled);
+                }
+                return mangled;
+            }
+        }
+        return moduleName;
+    }
+
     function tryFindNonRelativeModuleNameInCache(cache: PerModuleNameCache | undefined, moduleName: string, containingDirectory: string, traceEnabled: boolean, host: ModuleResolutionHost): SearchResult<Resolved> {
         const result = cache && cache.get(containingDirectory);
         if (result) {

tests/baselines/reference/library-reference-scoped-packages.js

@@ -0,0 +1,11 @@
+//// [tests/cases/conformance/references/library-reference-scoped-packages.ts] ////
+
+//// [index.d.ts]
+export const y = 0;
+
+//// [a.ts]
+/// <reference types="@beep/boop" />
+
+
+//// [a.js]
+/// <reference types="@beep/boop" />

tests/baselines/reference/library-reference-scoped-packages.symbols

@@ -0,0 +1,7 @@
+=== /a.ts ===
+/// <reference types="@beep/boop" />
+No type information for this code.
+No type information for this code.=== /node_modules/@types/beep__boop/index.d.ts ===
+export const y = 0;
+>y : Symbol(y, Decl(index.d.ts, 0, 12))
+

tests/baselines/reference/library-reference-scoped-packages.trace.json

@@ -0,0 +1,12 @@
+[
+    "======== Resolving type reference directive '@beep/boop', containing file '/a.ts', root directory 'types'. ========",
+    "Resolving with primary search path 'types'.",
+    "Directory 'types/@beep' does not exist, skipping all lookups in it.",
+    "Looking up in 'node_modules' folder, initial location '/'.",
+    "Scoped package detected, looking in 'beep__boop'",
+    "File '/node_modules/@types/beep__boop.d.ts' does not exist.",
+    "File '/node_modules/@types/beep__boop/package.json' does not exist.",
+    "File '/node_modules/@types/beep__boop/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/@types/beep__boop/index.d.ts', result '/node_modules/@types/beep__boop/index.d.ts'.",
+    "======== Type reference directive '@beep/boop' was successfully resolved to '/node_modules/@types/beep__boop/index.d.ts', primary: false. ========"
+]

tests/baselines/reference/library-reference-scoped-packages.types

@@ -0,0 +1,8 @@
+=== /a.ts ===
+/// <reference types="@beep/boop" />
+No type information for this code.
+No type information for this code.=== /node_modules/@types/beep__boop/index.d.ts ===
+export const y = 0;
+>y : 0
+>0 : 0
+

tests/baselines/reference/scopedPackages.js

@@ -0,0 +1,20 @@
+//// [tests/cases/conformance/moduleResolution/scopedPackages.ts] ////
+
+//// [index.d.ts]
+export const x: number;
+
+//// [index.d.ts]
+export const y: number;
+
+//// [z.d.ts]
+export const z: number;
+
+//// [a.ts]
+import { x } from "@cow/boy";
+import { y } from "@be/bop";
+import { z } from "@be/bop/e/z";
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/scopedPackages.symbols

@@ -0,0 +1,22 @@
+=== /a.ts ===
+import { x } from "@cow/boy";
+>x : Symbol(x, Decl(a.ts, 0, 8))
+
+import { y } from "@be/bop";
+>y : Symbol(y, Decl(a.ts, 1, 8))
+
+import { z } from "@be/bop/e/z";
+>z : Symbol(z, Decl(a.ts, 2, 8))
+
+=== /node_modules/@cow/boy/index.d.ts ===
+export const x: number;
+>x : Symbol(x, Decl(index.d.ts, 0, 12))
+
+=== /node_modules/@types/be__bop/index.d.ts ===
+export const y: number;
+>y : Symbol(y, Decl(index.d.ts, 0, 12))
+
+=== /node_modules/@types/be__bop/e/z.d.ts ===
+export const z: number;
+>z : Symbol(z, Decl(z.d.ts, 0, 12))
+

tests/baselines/reference/scopedPackages.trace.json

@@ -0,0 +1,30 @@
+[
+    "======== Resolving module '@cow/boy' from '/a.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module '@cow/boy' from 'node_modules' folder, target file type 'TypeScript'.",
+    "File '/node_modules/@cow/boy.ts' does not exist.",
+    "File '/node_modules/@cow/boy.tsx' does not exist.",
+    "File '/node_modules/@cow/boy.d.ts' does not exist.",
+    "File '/node_modules/@cow/boy/package.json' does not exist.",
+    "File '/node_modules/@cow/boy/index.ts' does not exist.",
+    "File '/node_modules/@cow/boy/index.tsx' does not exist.",
+    "File '/node_modules/@cow/boy/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/@cow/boy/index.d.ts', result '/node_modules/@cow/boy/index.d.ts'.",
+    "======== Module name '@cow/boy' was successfully resolved to '/node_modules/@cow/boy/index.d.ts'. ========",
+    "======== Resolving module '@be/bop' from '/a.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module '@be/bop' from 'node_modules' folder, target file type 'TypeScript'.",
+    "Scoped package detected, looking in 'be__bop'",
+    "File '/node_modules/@types/be__bop.d.ts' does not exist.",
+    "File '/node_modules/@types/be__bop/package.json' does not exist.",
+    "File '/node_modules/@types/be__bop/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/@types/be__bop/index.d.ts', result '/node_modules/@types/be__bop/index.d.ts'.",
+    "======== Module name '@be/bop' was successfully resolved to '/node_modules/@types/be__bop/index.d.ts'. ========",
+    "======== Resolving module '@be/bop/e/z' from '/a.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module '@be/bop/e/z' from 'node_modules' folder, target file type 'TypeScript'.",
+    "Scoped package detected, looking in 'be__bop/e/z'",
+    "File '/node_modules/@types/be__bop/e/z.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/@types/be__bop/e/z.d.ts', result '/node_modules/@types/be__bop/e/z.d.ts'.",
+    "======== Module name '@be/bop/e/z' was successfully resolved to '/node_modules/@types/be__bop/e/z.d.ts'. ========"
+]

tests/baselines/reference/scopedPackages.types

@@ -0,0 +1,22 @@
+=== /a.ts ===
+import { x } from "@cow/boy";
+>x : number
+
+import { y } from "@be/bop";
+>y : number
+
+import { z } from "@be/bop/e/z";
+>z : number
+
+=== /node_modules/@cow/boy/index.d.ts ===
+export const x: number;
+>x : number
+
+=== /node_modules/@types/be__bop/index.d.ts ===
+export const y: number;
+>y : number
+
+=== /node_modules/@types/be__bop/e/z.d.ts ===
+export const z: number;
+>z : number
+

tests/baselines/reference/scopedPackagesClassic.js

@@ -0,0 +1,12 @@
+//// [tests/cases/conformance/moduleResolution/scopedPackagesClassic.ts] ////
+
+//// [index.d.ts]
+export const x = 0;
+
+//// [a.ts]
+import { x } from "@see/saw";
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/scopedPackagesClassic.symbols

@@ -0,0 +1,8 @@
+=== /a.ts ===
+import { x } from "@see/saw";
+>x : Symbol(x, Decl(a.ts, 0, 8))
+
+=== /node_modules/@types/see__saw/index.d.ts ===
+export const x = 0;
+>x : Symbol(x, Decl(index.d.ts, 0, 12))
+

tests/baselines/reference/scopedPackagesClassic.trace.json

@@ -0,0 +1,9 @@
+[
+    "======== Resolving module '@see/saw' from '/a.ts'. ========",
+    "Explicitly specified module resolution kind: 'Classic'.",
+    "Scoped package detected, looking in 'see__saw'",
+    "File '/node_modules/@types/see__saw.d.ts' does not exist.",
+    "File '/node_modules/@types/see__saw/package.json' does not exist.",
+    "File '/node_modules/@types/see__saw/index.d.ts' exist - use it as a name resolution result.",
+    "======== Module name '@see/saw' was successfully resolved to '/node_modules/@types/see__saw/index.d.ts'. ========"
+]

tests/baselines/reference/scopedPackagesClassic.types

@@ -0,0 +1,9 @@
+=== /a.ts ===
+import { x } from "@see/saw";
+>x : 0
+
+=== /node_modules/@types/see__saw/index.d.ts ===
+export const x = 0;
+>x : 0
+>0 : 0
+

tests/cases/conformance/moduleResolution/scopedPackages.ts

@@ -0,0 +1,17 @@
+// @noImplicitReferences: true
+// @traceResolution: true
+// @typeRoots: types
+
+// @filename: /node_modules/@cow/boy/index.d.ts
+export const x: number;
+
+// @filename: /node_modules/@types/be__bop/index.d.ts
+export const y: number;
+
+// @filename: /node_modules/@types/be__bop/e/z.d.ts
+export const z: number;
+
+// @filename: /a.ts
+import { x } from "@cow/boy";
+import { y } from "@be/bop";
+import { z } from "@be/bop/e/z";

tests/cases/conformance/moduleResolution/scopedPackagesClassic.ts

@@ -0,0 +1,10 @@
+// @noImplicitReferences: true
+// @traceResolution: true
+// @typeRoots: types
+// @moduleResolution: classic
+
+// @filename: /node_modules/@types/see__saw/index.d.ts
+export const x = 0;
+
+// @filename: /a.ts
+import { x } from "@see/saw";

tests/cases/conformance/references/library-reference-scoped-packages.ts

@@ -0,0 +1,9 @@
+// @noImplicitReferences: true
+// @traceResolution: true
+// @typeRoots: types
+
+// @filename: /node_modules/@types/beep__boop/index.d.ts
+export const y = 0;
+
+// @filename: /a.ts
+/// <reference types="@beep/boop" />