feat: auto-omit MCP content when no servers are configured (#5889)

* feat: auto-omit MCP content when no servers are configured

- Modify system prompt generation to detect when no MCP servers are defined
- Only include MCP sections when mode has mcp group AND servers exist
- Pass undefined mcpHub to capabilities and tools when no servers available
- Reduces system prompt verbosity when MCP functionality is not in use

* fix: add missing Uri and RelativePattern exports to VSCode mocks

- Added Uri and RelativePattern exports to global VSCode mock in __mocks__/vscode.js
- Fixed McpHub.spec.ts VSCode mock to include Uri and RelativePattern
- Fixed Task.spec.ts VSCode mock to include Uri and RelativePattern with proper TypeScript typing
- Resolves unhandled rejection errors in unit tests caused by missing VSCode API mocks

* fix: add proper TypeScript typing for RelativePattern in McpHub test mock

* fix: resolve unit test failures in PR #5889

- Fix VSCode mock onDidChangeWorkspaceFolders to accept callback parameter
- Update MCP test mocks to properly test auto-omit functionality
- Update test snapshots to reflect new MCP content omission behavior
- All core functionality tests now passing

* chore: remove package-lock.json as project uses npm

* fix: remove unrelated mock changes from PR

---------

Co-authored-by: Roo Code <[email protected]>
Co-authored-by: Daniel Riccio <[email protected]>

Author: 3 people

src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-disabled.snap

@@ -168,9 +168,9 @@ const mockContext = {
 } as unknown as vscode.ExtensionContext
 
 // Instead of extending McpHub, create a mock that implements just what we need
-const createMockMcpHub = (): McpHub =>
+const createMockMcpHub = (withServers: boolean = false): McpHub =>
 	({
-		getServers: () => [],
+		getServers: () => (withServers ? [{ name: "test-server", disabled: false }] : []),
 		getMcpServersPath: async () => "/mock/mcp/path",
 		getMcpSettingsFilePath: async () => "/mock/settings/path",
 		dispose: async () => {},
@@ -236,7 +236,7 @@ describe("addCustomInstructions", () => {
 	})
 
 	it("should include MCP server creation info when enabled", async () => {
-		const mockMcpHub = createMockMcpHub()
+		const mockMcpHub = createMockMcpHub(true)
 
 		const prompt = await SYSTEM_PROMPT(
 			mockContext,
@@ -262,7 +262,7 @@ describe("addCustomInstructions", () => {
 	})
 
 	it("should exclude MCP server creation info when disabled", async () => {
-		const mockMcpHub = createMockMcpHub()
+		const mockMcpHub = createMockMcpHub(false)
 
 		const prompt = await SYSTEM_PROMPT(
 			mockContext,

src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-enabled.snap

@@ -168,9 +168,9 @@ const mockContext = {
 } as unknown as vscode.ExtensionContext
 
 // Instead of extending McpHub, create a mock that implements just what we need
-const createMockMcpHub = (): McpHub =>
+const createMockMcpHub = (withServers: boolean = false): McpHub =>
 	({
-		getServers: () => [],
+		getServers: () => (withServers ? [{ name: "test-server", disabled: false }] : []),
 		getMcpServersPath: async () => "/mock/mcp/path",
 		getMcpSettingsFilePath: async () => "/mock/settings/path",
 		dispose: async () => {},
@@ -250,7 +250,7 @@ describe("SYSTEM_PROMPT", () => {
 	})
 
 	it("should include MCP server info when mcpHub is provided", async () => {
-		mockMcpHub = createMockMcpHub()
+		mockMcpHub = createMockMcpHub(true)
 
 		const prompt = await SYSTEM_PROMPT(
 			mockContext,

src/core/prompts/__tests__/__snapshots__/system-prompt/with-mcp-hub-provided.snap

@@ -71,9 +71,14 @@ async function generatePrompt(
 	const modeConfig = getModeBySlug(mode, customModeConfigs) || modes.find((m) => m.slug === mode) || modes[0]
 	const { roleDefinition, baseInstructions } = getModeSelection(mode, promptComponent, customModeConfigs)
 
+	// Check if MCP functionality should be included
+	const hasMcpGroup = modeConfig.groups.some((groupEntry) => getGroupName(groupEntry) === "mcp")
+	const hasMcpServers = mcpHub && mcpHub.getServers().length > 0
+	const shouldIncludeMcp = hasMcpGroup && hasMcpServers
+
 	const [modesSection, mcpServersSection] = await Promise.all([
 		getModesSection(context),
-		modeConfig.groups.some((groupEntry) => getGroupName(groupEntry) === "mcp")
+		shouldIncludeMcp
 			? getMcpServersSection(mcpHub, effectiveDiffStrategy, enableMcpServerCreation)
 			: Promise.resolve(""),
 	])
@@ -93,7 +98,7 @@ ${getToolDescriptionsForMode(
 	codeIndexManager,
 	effectiveDiffStrategy,
 	browserViewportSize,
-	mcpHub,
+	shouldIncludeMcp ? mcpHub : undefined,
 	customModeConfigs,
 	experiments,
 	partialReadsEnabled,
@@ -104,7 +109,7 @@ ${getToolUseGuidelinesSection(codeIndexManager)}
 
 ${mcpServersSection}
 
-${getCapabilitiesSection(cwd, supportsComputerUse, mcpHub, effectiveDiffStrategy, codeIndexManager)}
+${getCapabilitiesSection(cwd, supportsComputerUse, shouldIncludeMcp ? mcpHub : undefined, effectiveDiffStrategy, codeIndexManager)}
 
 ${modesSection}
 

src/core/prompts/__tests__/add-custom-instructions.spec.ts

@@ -93,7 +93,6 @@ describe("McpHub", () => {
 		// Mock console.error to suppress error messages during tests
 		console.error = vi.fn()
 
-
 		const mockUri: Uri = {
 			scheme: "file",
 			authority: "",