Fix hook cwd resolution in multi-root workspaces (microsoft#295365)

Previously, computeHooks() and getHookDiscoveryInfo() used
folders[0] for the workspaceRootUri of all hook files, causing
hooks in non-first workspace folders to have incorrect cwd.

Now each hook file's cwd is resolved using getWorkspaceFolder()
for that specific hook file's URI, ensuring hooks run in the
correct workspace folder.

Adds a test that verifies multi-root cwd resolution.

Author: roblourens

src/vs/workbench/contrib/chat/common/promptSyntax/service/promptsServiceImpl.ts

@@ -1026,10 +1026,6 @@ export class PromptsService extends Disposable implements IPromptsService {
 		const userHomeUri = await this.pathService.userHome();
 		const userHome = userHomeUri.scheme === Schemas.file ? userHomeUri.fsPath : userHomeUri.path;
 
-		// Get workspace root for resolving relative cwd paths
-		const workspaceFolder = this.workspaceService.getWorkspace().folders[0];
-		const workspaceRootUri = workspaceFolder?.uri;
-
 		let hasDisabledClaudeHooks = false;
 		const collectedHooks: Record<HookType, IHookCommand[]> = {
 			[HookType.SessionStart]: [],
@@ -1042,11 +1038,18 @@ export class PromptsService extends Disposable implements IPromptsService {
 			[HookType.Stop]: [],
 		};
 
+		const defaultFolder = this.workspaceService.getWorkspace().folders[0];
+
 		for (const hookFile of hookFiles) {
 			try {
 				const content = await this.fileService.readFile(hookFile.uri);
 				const json = parseJSONC(content.value.toString());
 
+				// Resolve the workspace folder that contains this hook file for cwd resolution,
+				// falling back to the first workspace folder for user-level hooks outside the workspace
+				const hookWorkspaceFolder = this.workspaceService.getWorkspaceFolder(hookFile.uri) ?? defaultFolder;
+				const workspaceRootUri = hookWorkspaceFolder?.uri;
+
 				// Use format-aware parsing that handles Copilot and Claude formats
 				const { format, hooks, disabledAllHooks } = parseHooksFromFile(hookFile.uri, json, workspaceRootUri, userHome);
 
@@ -1339,10 +1342,6 @@ export class PromptsService extends Disposable implements IPromptsService {
 		const userHomeUri = await this.pathService.userHome();
 		const userHome = userHomeUri.scheme === Schemas.file ? userHomeUri.fsPath : userHomeUri.path;
 
-		// Get workspace root for resolving relative cwd paths
-		const workspaceFolder = this.workspaceService.getWorkspace().folders[0];
-		const workspaceRootUri = workspaceFolder?.uri;
-
 		const useClaudeHooks = this.configurationService.getValue<boolean>(PromptsConfig.USE_CLAUDE_HOOKS);
 		const hookFiles = await this.listPromptFiles(PromptsType.hook, token);
 		for (const promptPath of hookFiles) {
@@ -1383,6 +1382,11 @@ export class PromptsService extends Disposable implements IPromptsService {
 					continue;
 				}
 
+				// Resolve the workspace folder that contains this hook file for cwd resolution,
+				// falling back to the first workspace folder for user-level hooks outside the workspace
+				const hookWorkspaceFolder = this.workspaceService.getWorkspaceFolder(uri) ?? this.workspaceService.getWorkspace().folders[0];
+				const workspaceRootUri = hookWorkspaceFolder?.uri;
+
 				// Use format-aware parsing to check for disabledAllHooks
 				const { disabledAllHooks } = parseHooksFromFile(uri, json, workspaceRootUri, userHome);
 

src/vs/workbench/contrib/chat/test/common/promptSyntax/service/promptsService.test.ts

@@ -38,7 +38,7 @@ import { TestContextService, TestUserDataProfileService } from '../../../../../.
 import { ChatRequestVariableSet, isPromptFileVariableEntry, toFileVariableEntry } from '../../../../common/attachments/chatVariableEntries.js';
 import { ComputeAutomaticInstructions, newInstructionsCollectionEvent } from '../../../../common/promptSyntax/computeAutomaticInstructions.js';
 import { PromptsConfig } from '../../../../common/promptSyntax/config/config.js';
-import { AGENTS_SOURCE_FOLDER, CLAUDE_CONFIG_FOLDER, INSTRUCTION_FILE_EXTENSION, INSTRUCTIONS_DEFAULT_SOURCE_FOLDER, LEGACY_MODE_DEFAULT_SOURCE_FOLDER, PROMPT_DEFAULT_SOURCE_FOLDER, PROMPT_FILE_EXTENSION } from '../../../../common/promptSyntax/config/promptFileLocations.js';
+import { AGENTS_SOURCE_FOLDER, CLAUDE_CONFIG_FOLDER, HOOKS_SOURCE_FOLDER, INSTRUCTION_FILE_EXTENSION, INSTRUCTIONS_DEFAULT_SOURCE_FOLDER, LEGACY_MODE_DEFAULT_SOURCE_FOLDER, PROMPT_DEFAULT_SOURCE_FOLDER, PROMPT_FILE_EXTENSION } from '../../../../common/promptSyntax/config/promptFileLocations.js';
 import { INSTRUCTIONS_LANGUAGE_ID, PROMPT_LANGUAGE_ID, PromptsType } from '../../../../common/promptSyntax/promptTypes.js';
 import { ExtensionAgentSourceType, ICustomAgent, IPromptFileContext, IPromptsService, PromptsStorage, Target } from '../../../../common/promptSyntax/service/promptsService.js';
 import { PromptsService } from '../../../../common/promptSyntax/service/promptsServiceImpl.js';
@@ -48,6 +48,7 @@ import { IPathService } from '../../../../../../services/path/common/pathService
 import { IFileMatch, IFileQuery, ISearchService } from '../../../../../../services/search/common/search.js';
 import { IExtensionService } from '../../../../../../services/extensions/common/extensions.js';
 import { ChatModeKind } from '../../../../common/constants.js';
+import { HookType } from '../../../../common/promptSyntax/hookSchema.js';
 
 suite('PromptsService', () => {
 	const disposables = ensureNoDisposablesAreLeakedInTestSuite();
@@ -3370,4 +3371,57 @@ suite('PromptsService', () => {
 				'Skill without header should be included when applying userInvocable filter (defaults to true)');
 		});
 	});
+
+	suite('hooks', () => {
+		test('multi-root workspace resolves cwd to per-hook-file workspace folder', async function () {
+			const folder1Uri = URI.file('/workspace-a');
+			const folder2Uri = URI.file('/workspace-b');
+
+			workspaceContextService.setWorkspace(testWorkspace(folder1Uri, folder2Uri));
+			testConfigService.setUserConfiguration(PromptsConfig.USE_CHAT_HOOKS, true);
+			testConfigService.setUserConfiguration(PromptsConfig.HOOKS_LOCATION_KEY, { [HOOKS_SOURCE_FOLDER]: true });
+
+			await mockFiles(fileService, [
+				{
+					path: '/workspace-a/.github/hooks/my-hook.json',
+					contents: [
+						JSON.stringify({
+							hooks: {
+								[HookType.PreToolUse]: [
+									{ type: 'command', command: 'echo folder-a' },
+								],
+							},
+						}),
+					],
+				},
+				{
+					path: '/workspace-b/.github/hooks/my-hook.json',
+					contents: [
+						JSON.stringify({
+							hooks: {
+								[HookType.PreToolUse]: [
+									{ type: 'command', command: 'echo folder-b' },
+								],
+							},
+						}),
+					],
+				},
+			]);
+
+			const result = await service.getHooks(CancellationToken.None);
+			assert.ok(result, 'Expected hooks result');
+
+			const preToolUseHooks = result.hooks[HookType.PreToolUse];
+			assert.ok(preToolUseHooks, 'Expected PreToolUse hooks');
+			assert.strictEqual(preToolUseHooks.length, 2, 'Expected two PreToolUse hooks');
+
+			const hookA = preToolUseHooks.find(h => h.command === 'echo folder-a');
+			const hookB = preToolUseHooks.find(h => h.command === 'echo folder-b');
+			assert.ok(hookA, 'Expected hook from folder-a');
+			assert.ok(hookB, 'Expected hook from folder-b');
+
+			assert.strictEqual(hookA.cwd?.path, folder1Uri.path, 'Hook from folder-a should have cwd pointing to workspace-a');
+			assert.strictEqual(hookB.cwd?.path, folder2Uri.path, 'Hook from folder-b should have cwd pointing to workspace-b');
+		});
+	});
 });