When installing unrelated package inside scoped packages dont invalidate resolutions from everything in the scoped package (#53873)

Author: sheetalkamat

src/compiler/moduleNameResolver.ts

@@ -1889,24 +1889,24 @@ export function pathContainsNodeModules(path: string): boolean {
  *
  * @internal
  */
-export function parseNodeModuleFromPath(resolved: string): string | undefined {
+export function parseNodeModuleFromPath(resolved: string, isFolder?: boolean): string | undefined {
     const path = normalizePath(resolved);
     const idx = path.lastIndexOf(nodeModulesPathPart);
     if (idx === -1) {
         return undefined;
     }
 
     const indexAfterNodeModules = idx + nodeModulesPathPart.length;
-    let indexAfterPackageName = moveToNextDirectorySeparatorIfAvailable(path, indexAfterNodeModules);
+    let indexAfterPackageName = moveToNextDirectorySeparatorIfAvailable(path, indexAfterNodeModules, isFolder);
     if (path.charCodeAt(indexAfterNodeModules) === CharacterCodes.at) {
-        indexAfterPackageName = moveToNextDirectorySeparatorIfAvailable(path, indexAfterPackageName);
+        indexAfterPackageName = moveToNextDirectorySeparatorIfAvailable(path, indexAfterPackageName, isFolder);
     }
     return path.slice(0, indexAfterPackageName);
 }
 
-function moveToNextDirectorySeparatorIfAvailable(path: string, prevSeparatorIndex: number): number {
+function moveToNextDirectorySeparatorIfAvailable(path: string, prevSeparatorIndex: number, isFolder: boolean | undefined): number {
     const nextSeparatorIndex = path.indexOf(directorySeparator, prevSeparatorIndex + 1);
-    return nextSeparatorIndex === -1 ? prevSeparatorIndex : nextSeparatorIndex;
+    return nextSeparatorIndex === -1 ? isFolder ? path.length : prevSeparatorIndex : nextSeparatorIndex;
 }
 
 function loadModuleFromFileNoPackageId(extensions: Extensions, candidate: string, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {

src/compiler/resolutionCache.ts

@@ -1152,7 +1152,7 @@ export function createResolutionCache(resolutionHost: ResolutionCacheHost, rootD
                 // If the invalidated file is from a node_modules package, invalidate everything else
                 // in the package since we might not get notifications for other files in the package.
                 // This hardens our logic against unreliable file watchers.
-                const packagePath = parseNodeModuleFromPath(fileOrDirectoryPath);
+                const packagePath = parseNodeModuleFromPath(fileOrDirectoryPath, /*isFolder*/ true);
                 if (packagePath) (startsWithPathChecks ||= new Set()).add(packagePath as Path);
             }
         }

src/testRunner/unittests/tscWatch/resolutionCache.ts

@@ -1,5 +1,6 @@
 import * as ts from "../../_namespaces/ts";
 import * as Utils from "../../_namespaces/Utils";
+import { libContent } from "../tsc/helpers";
 import {
     createWatchedSystem,
     File,
@@ -621,4 +622,64 @@ declare namespace NodeJS {
             },
         ]
     });
+
+    verifyTscWatch({
+        scenario,
+        subScenario: "scoped package installation",
+        commandLineArgs: ["--w", "-p", `.`, "--traceResolution", "--extendedDiagnostics"],
+        sys: () => createWatchedSystem({
+            "/user/username/projects/myproject/lib/app.ts": Utils.dedent`
+                import { myapp } from "@myapp/ts-types";
+                const x: 10 = myapp;
+            `,
+            "/user/username/projects/myproject/tsconfig.json": "{}",
+            [libFile.path]: libContent,
+        }, { currentDirectory: "/user/username/projects/myproject" }),
+        edits: [
+            {
+                caption: "npm install unrelated non scoped",
+                edit: sys => sys.ensureFileOrFolder({
+                    path: `/user/username/projects/myproject/node_modules/unrelated/index.d.ts`,
+                    content: `export const unrelated = 10;`
+                }),
+                timeouts: sys => {
+                    sys.runQueuedTimeoutCallbacks();
+                    sys.runQueuedTimeoutCallbacks();
+                },
+            },
+            {
+                caption: "npm install unrelated scoped in myapp",
+                edit: sys => sys.ensureFileOrFolder({
+                    path: `/user/username/projects/myproject/node_modules/@myapp/unrelated/index.d.ts`,
+                    content: `export const myappUnrelated = 10;`
+                }),
+                timeouts: sys => {
+                    sys.runQueuedTimeoutCallbacks();
+                    sys.runQueuedTimeoutCallbacks();
+                },
+            },
+            {
+                caption: "npm install unrelated2 scoped in myapp",
+                edit: sys => sys.ensureFileOrFolder({
+                    path: `/user/username/projects/myproject/node_modules/@myapp/unrelated2/index.d.ts`,
+                    content: `export const myappUnrelated2 = 10;`
+                }),
+                timeouts: sys => {
+                    sys.runQueuedTimeoutCallbacks();
+                    sys.runQueuedTimeoutCallbacks();
+                },
+            },
+            {
+                caption: "npm install ts-types",
+                edit: sys => sys.ensureFileOrFolder({
+                    path: `/user/username/projects/myproject/node_modules/@myapp/ts-types/index.d.ts`,
+                    content: `export const myapp = 10;`
+                }),
+                timeouts: sys => {
+                    sys.runQueuedTimeoutCallbacks();
+                    sys.runQueuedTimeoutCallbacks();
+                },
+            },
+        ]
+    });
 });