import statement from "node" in js source file could produce correct …

…declaration path. (microsoft#41816)

* fix microsoft#41800

* add test

* fix test

src/compiler/moduleNameResolver.ts

@@ -1422,7 +1422,8 @@ namespace ts {
     export function getPackageNameFromTypesPackageName(mangledName: string): string {
         const withoutAtTypePrefix = removePrefix(mangledName, "@types/");
         if (withoutAtTypePrefix !== mangledName) {
-            return unmangleScopedPackageName(withoutAtTypePrefix);
+            const withoutAtTypeNodePrefix = removePrefix(withoutAtTypePrefix, "node/");
+            return unmangleScopedPackageName(withoutAtTypeNodePrefix);
         }
         return mangledName;
     }

tests/baselines/reference/importDeclFromTypeNodeInJsSource.js

@@ -0,0 +1,40 @@
+//// [tests/cases/compiler/importDeclFromTypeNodeInJsSource.ts] ////
+
+//// [index.d.ts]
+/// <reference path="events.d.ts" />
+//// [events.d.ts]
+declare module "events" {
+    namespace EventEmitter {
+        class EventEmitter {
+            constructor();
+        }
+    }
+    export = EventEmitter;
+}
+
+//// [b.js]
+import { EventEmitter } from 'events';
+class Foo extends EventEmitter {
+    constructor() {
+        super();
+    }
+}
+export default Foo;
+
+//// [b.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const events_1 = require("events");
+class Foo extends events_1.EventEmitter {
+    constructor() {
+        super();
+    }
+}
+exports.default = Foo;
+
+
+//// [b.d.ts]
+export default Foo;
+declare class Foo extends EventEmitter {
+}
+import { EventEmitter } from "events";

tests/baselines/reference/importDeclFromTypeNodeInJsSource.symbols

@@ -0,0 +1,35 @@
+=== /src/node_modules/@types/node/index.d.ts ===
+/// <reference path="events.d.ts" />
+No type information for this code.=== /src/node_modules/@types/node/events.d.ts ===
+declare module "events" {
+>"events" : Symbol("events", Decl(events.d.ts, 0, 0))
+
+    namespace EventEmitter {
+>EventEmitter : Symbol(EventEmitter, Decl(events.d.ts, 0, 25))
+
+        class EventEmitter {
+>EventEmitter : Symbol(EventEmitter, Decl(events.d.ts, 1, 28))
+
+            constructor();
+        }
+    }
+    export = EventEmitter;
+>EventEmitter : Symbol(EventEmitter, Decl(events.d.ts, 0, 25))
+}
+
+=== /src/b.js ===
+import { EventEmitter } from 'events';
+>EventEmitter : Symbol(EventEmitter, Decl(b.js, 0, 8))
+
+class Foo extends EventEmitter {
+>Foo : Symbol(Foo, Decl(b.js, 0, 38))
+>EventEmitter : Symbol(EventEmitter, Decl(b.js, 0, 8))
+
+    constructor() {
+        super();
+>super : Symbol(EventEmitter, Decl(events.d.ts, 1, 28))
+    }
+}
+export default Foo;
+>Foo : Symbol(Foo, Decl(b.js, 0, 38))
+

tests/baselines/reference/importDeclFromTypeNodeInJsSource.types

@@ -0,0 +1,36 @@
+=== /src/node_modules/@types/node/index.d.ts ===
+/// <reference path="events.d.ts" />
+No type information for this code.=== /src/node_modules/@types/node/events.d.ts ===
+declare module "events" {
+>"events" : typeof import("events")
+
+    namespace EventEmitter {
+>EventEmitter : typeof EventEmitter
+
+        class EventEmitter {
+>EventEmitter : EventEmitter
+
+            constructor();
+        }
+    }
+    export = EventEmitter;
+>EventEmitter : typeof EventEmitter
+}
+
+=== /src/b.js ===
+import { EventEmitter } from 'events';
+>EventEmitter : typeof EventEmitter
+
+class Foo extends EventEmitter {
+>Foo : Foo
+>EventEmitter : EventEmitter
+
+    constructor() {
+        super();
+>super() : void
+>super : typeof EventEmitter
+    }
+}
+export default Foo;
+>Foo : Foo
+

tests/cases/compiler/importDeclFromTypeNodeInJsSource.ts

@@ -0,0 +1,26 @@
+// @target: esnext
+// @module: commonjs
+// @allowJs: true
+// @checkJs: true
+// @declaration: true
+// @outDir: ./dist
+// @filename: /src/node_modules/@types/node/index.d.ts
+/// <reference path="events.d.ts" />
+// @filename: /src/node_modules/@types/node/events.d.ts
+declare module "events" {
+    namespace EventEmitter {
+        class EventEmitter {
+            constructor();
+        }
+    }
+    export = EventEmitter;
+}
+
+// @filename: /src/b.js
+import { EventEmitter } from 'events';
+class Foo extends EventEmitter {
+    constructor() {
+        super();
+    }
+}
+export default Foo;