fix: clean up stale vectors on directory deletion and add Qdrant collection alias

- Detect directory deletions in FileWatcher by checking cache for child
  paths, queuing all children for vector deletion
- Add human-readable Qdrant collection alias based on workspace folder name
- Add tests for both features

Addresses #12115

Author: roomote

src/services/code-index/processors/__tests__/file-watcher.spec.ts

@@ -108,6 +108,7 @@ describe("FileWatcher", () => {
 			getHash: vi.fn(),
 			updateHash: vi.fn(),
 			deleteHash: vi.fn(),
+			getAllHashes: vi.fn().mockReturnValue({}),
 		}
 
 		mockEmbedder = {
@@ -277,6 +278,75 @@ describe("FileWatcher", () => {
 		})
 	})
 
+	describe("directory deletion handling", () => {
+		it("should queue all cached child files for deletion when a directory is deleted", async () => {
+			// Setup cache with files that are children of a directory
+			const directoryPath = "/mock/workspace/src/components"
+			mockCacheManager.getAllHashes.mockReturnValue({
+				[`${directoryPath}/Button.tsx`]: "hash1",
+				[`${directoryPath}/Modal.tsx`]: "hash2",
+				[`${directoryPath}/utils/helpers.ts`]: "hash3",
+				["/mock/workspace/src/index.ts"]: "hash4",
+			})
+
+			await fileWatcher.initialize()
+
+			// Trigger directory deletion event
+			await mockOnDidDelete({ fsPath: directoryPath })
+
+			// Wait for batch processing
+			await new Promise((resolve) => setTimeout(resolve, 600))
+
+			// Verify that deletePointsByMultipleFilePaths was called with all child paths
+			expect(mockVectorStore.deletePointsByMultipleFilePaths).toHaveBeenCalled()
+			const deletedPaths = mockVectorStore.deletePointsByMultipleFilePaths.mock.calls[0][0]
+			expect(deletedPaths).toContain(`${directoryPath}/Button.tsx`)
+			expect(deletedPaths).toContain(`${directoryPath}/Modal.tsx`)
+			expect(deletedPaths).toContain(`${directoryPath}/utils/helpers.ts`)
+			// Should NOT include files outside the deleted directory
+			expect(deletedPaths).not.toContain("/mock/workspace/src/index.ts")
+		})
+
+		it("should handle single file deletion normally when no cached children exist", async () => {
+			const filePath = "/mock/workspace/src/index.ts"
+			mockCacheManager.getAllHashes.mockReturnValue({
+				[filePath]: "hash1",
+				["/mock/workspace/src/other.ts"]: "hash2",
+			})
+
+			await fileWatcher.initialize()
+
+			// Trigger single file deletion
+			await mockOnDidDelete({ fsPath: filePath })
+
+			// Wait for batch processing
+			await new Promise((resolve) => setTimeout(resolve, 600))
+
+			// Should process deletion for just the one file
+			expect(mockVectorStore.deletePointsByMultipleFilePaths).toHaveBeenCalled()
+			const deletedPaths = mockVectorStore.deletePointsByMultipleFilePaths.mock.calls[0][0]
+			expect(deletedPaths).toContain(filePath)
+			expect(deletedPaths).not.toContain("/mock/workspace/src/other.ts")
+		})
+
+		it("should handle deletion of path not in cache", async () => {
+			mockCacheManager.getAllHashes.mockReturnValue({
+				["/mock/workspace/src/other.ts"]: "hash1",
+			})
+
+			await fileWatcher.initialize()
+
+			// Trigger deletion of a file not in cache
+			await mockOnDidDelete({ fsPath: "/mock/workspace/src/nonexistent.ts" })
+
+			// Wait for batch processing
+			await new Promise((resolve) => setTimeout(resolve, 600))
+
+			// Should still attempt deletion (the vector store will handle the no-op)
+			expect(mockVectorStore.deletePointsByMultipleFilePaths).toHaveBeenCalled()
+		})
+	})
+
 	describe("dispose", () => {
 		it("should dispose of the watcher when disposed", async () => {
 			await fileWatcher.initialize()

src/services/code-index/processors/file-watcher.ts

@@ -1,3 +1,4 @@
+import * as path from "path"
 import * as vscode from "vscode"
 import {
 	QDRANT_CODE_BLOCK_NAMESPACE,
@@ -152,11 +153,35 @@ export class FileWatcher implements IFileWatcher {
 	}
 
 	/**
-	 * Handles file deletion events
-	 * @param uri URI of the deleted file
+	 * Handles file deletion events.
+	 * When a directory is deleted, VSCode's FileSystemWatcher may not fire
+	 * individual delete events for each file inside it. This method detects
+	 * directory deletions by checking the cache for any files whose paths
+	 * start with the deleted path prefix, and queues them all for deletion.
+	 * @param uri URI of the deleted file or directory
 	 */
 	private async handleFileDeleted(uri: vscode.Uri): Promise<void> {
-		this.accumulatedEvents.set(uri.fsPath, { uri, type: "delete" })
+		const deletedPath = uri.fsPath
+
+		// Check if any cached files have this as a prefix (directory deletion)
+		const allHashes = this.cacheManager.getAllHashes()
+		const childPaths = Object.keys(allHashes).filter(
+			(cachedPath) => cachedPath.startsWith(deletedPath + path.sep) || cachedPath === deletedPath,
+		)
+
+		if (childPaths.length > 1) {
+			// Directory was deleted - queue all child files for deletion
+			for (const childPath of childPaths) {
+				this.accumulatedEvents.set(childPath, {
+					uri: vscode.Uri.file(childPath),
+					type: "delete",
+				})
+			}
+		} else {
+			// Single file deletion (or a file matching exactly)
+			this.accumulatedEvents.set(deletedPath, { uri, type: "delete" })
+		}
+
 		this.scheduleBatchProcessing()
 	}
 

src/services/code-index/vector-store/__tests__/qdrant-client.spec.ts

@@ -35,6 +35,7 @@ const mockQdrantClientInstance = {
 	createCollection: vitest.fn(),
 	deleteCollection: vitest.fn(),
 	createPayloadIndex: vitest.fn(),
+	updateCollectionAliases: vitest.fn(),
 	upsert: vitest.fn(),
 	query: vitest.fn(),
 	delete: vitest.fn(),
@@ -980,6 +981,88 @@ describe("QdrantVectorStore", () => {
 		})
 	})
 
+	describe("workspace alias creation", () => {
+		it("should create a workspace alias during initialization", async () => {
+			mockQdrantClientInstance.getCollection.mockRejectedValue({
+				response: { status: 404 },
+				message: "Not found",
+			})
+			mockQdrantClientInstance.createCollection.mockResolvedValue(true as any)
+			mockQdrantClientInstance.createPayloadIndex.mockResolvedValue({} as any)
+			mockQdrantClientInstance.updateCollectionAliases.mockResolvedValue(true as any)
+			vitest.spyOn(console, "log").mockImplementation(() => {})
+
+			await vectorStore.initialize()
+
+			expect(mockQdrantClientInstance.updateCollectionAliases).toHaveBeenCalledTimes(1)
+			expect(mockQdrantClientInstance.updateCollectionAliases).toHaveBeenCalledWith({
+				actions: [
+					{
+						create_alias: {
+							collection_name: expectedCollectionName,
+							alias_name: "workspace",
+						},
+					},
+				],
+			})
+			;(console.log as any).mockRestore()
+		})
+
+		it("should not fail initialization if alias creation fails", async () => {
+			mockQdrantClientInstance.getCollection.mockRejectedValue({
+				response: { status: 404 },
+				message: "Not found",
+			})
+			mockQdrantClientInstance.createCollection.mockResolvedValue(true as any)
+			mockQdrantClientInstance.createPayloadIndex.mockResolvedValue({} as any)
+			mockQdrantClientInstance.updateCollectionAliases.mockRejectedValue(new Error("Alias creation failed"))
+			vitest.spyOn(console, "warn").mockImplementation(() => {})
+
+			const result = await vectorStore.initialize()
+
+			// Should still succeed even if alias creation fails
+			expect(result).toBe(true)
+			expect(mockQdrantClientInstance.updateCollectionAliases).toHaveBeenCalledTimes(1)
+			expect(console.warn).toHaveBeenCalledWith(
+				expect.stringContaining("Could not create workspace alias"),
+				expect.any(String),
+			)
+			;(console.warn as any).mockRestore()
+		})
+
+		it("should sanitize workspace name for alias", async () => {
+			// Create a vector store with a workspace path that has special characters
+			const specialPathStore = new QdrantVectorStore(
+				"/test/My Project (v2)",
+				mockQdrantUrl,
+				mockVectorSize,
+				mockApiKey,
+			)
+			mockQdrantClientInstance.getCollection.mockRejectedValue({
+				response: { status: 404 },
+				message: "Not found",
+			})
+			mockQdrantClientInstance.createCollection.mockResolvedValue(true as any)
+			mockQdrantClientInstance.createPayloadIndex.mockResolvedValue({} as any)
+			mockQdrantClientInstance.updateCollectionAliases.mockResolvedValue(true as any)
+			vitest.spyOn(console, "log").mockImplementation(() => {})
+
+			await specialPathStore.initialize()
+
+			expect(mockQdrantClientInstance.updateCollectionAliases).toHaveBeenCalledWith({
+				actions: [
+					{
+						create_alias: {
+							collection_name: expect.any(String),
+							alias_name: "my-project--v2-",
+						},
+					},
+				],
+			})
+			;(console.log as any).mockRestore()
+		})
+	})
+
 	it("should return true when collection exists", async () => {
 		mockQdrantClientInstance.getCollection.mockResolvedValue({
 			config: {

src/services/code-index/vector-store/qdrant-client.ts

@@ -194,6 +194,10 @@ export class QdrantVectorStore implements IVectorStore {
 
 			// Create payload indexes
 			await this._createPayloadIndexes()
+
+			// Create a human-readable alias for the collection using the workspace folder name
+			await this._createWorkspaceAlias()
+
 			return created
 		} catch (error: any) {
 			const errorMessage = error?.message || error
@@ -331,6 +335,41 @@ export class QdrantVectorStore implements IVectorStore {
 		}
 	}
 
+	/**
+	 * Creates a human-readable Qdrant alias for the collection using the workspace folder name.
+	 * This allows external tools to discover and query the collection without reverse-engineering
+	 * the hashed naming scheme. Non-fatal: failures are logged but do not block initialization.
+	 */
+	private async _createWorkspaceAlias(): Promise<void> {
+		try {
+			const workspaceName = path.basename(this.workspacePath)
+			if (!workspaceName) {
+				return
+			}
+
+			// Sanitize the alias name: only allow alphanumeric, hyphens, underscores
+			const aliasName = workspaceName.replace(/[^a-zA-Z0-9_-]/g, "-").toLowerCase()
+			if (!aliasName) {
+				return
+			}
+
+			await this.client.updateCollectionAliases({
+				actions: [
+					{
+						create_alias: {
+							collection_name: this.collectionName,
+							alias_name: aliasName,
+						},
+					},
+				],
+			})
+			console.log(`[QdrantVectorStore] Created alias "${aliasName}" for collection "${this.collectionName}"`)
+		} catch (aliasError: any) {
+			// Non-fatal - log warning but don't fail initialization
+			console.warn(`[QdrantVectorStore] Could not create workspace alias:`, aliasError?.message || aliasError)
+		}
+	}
+
 	/**
 	 * Upserts points into the vector store
 	 * @param points Array of points to upsert