Adds centralized support to log slash commands + sub commands (#5128)

packages/cli/src/ui/hooks/slashCommandProcessor.test.ts

@@ -4,6 +4,21 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+const { logSlashCommand, SlashCommandEvent } = vi.hoisted(() => ({
+  logSlashCommand: vi.fn(),
+  SlashCommandEvent: vi.fn((command, subCommand) => ({ command, subCommand })),
+}));
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...original,
+    logSlashCommand,
+    SlashCommandEvent,
+  };
+});
+
 const { mockProcessExit } = vi.hoisted(() => ({
   mockProcessExit: vi.fn((_code?: number): never => undefined as never),
 }));
@@ -814,4 +829,83 @@ describe('useSlashCommandProcessor', () => {
       expect(abortSpy).toHaveBeenCalledTimes(1);
     });
   });
+
+  describe('Slash Command Logging', () => {
+    const mockCommandAction = vi.fn().mockResolvedValue({ type: 'handled' });
+    const loggingTestCommands: SlashCommand[] = [
+      createTestCommand({
+        name: 'logtest',
+        action: mockCommandAction,
+      }),
+      createTestCommand({
+        name: 'logwithsub',
+        subCommands: [
+          createTestCommand({
+            name: 'sub',
+            action: mockCommandAction,
+          }),
+        ],
+      }),
+      createTestCommand({
+        name: 'logalias',
+        altNames: ['la'],
+        action: mockCommandAction,
+      }),
+    ];
+
+    beforeEach(() => {
+      mockCommandAction.mockClear();
+      vi.mocked(logSlashCommand).mockClear();
+      vi.mocked(SlashCommandEvent).mockClear();
+    });
+
+    it('should log a simple slash command', async () => {
+      const result = setupProcessorHook(loggingTestCommands);
+      await waitFor(() =>
+        expect(result.current.slashCommands.length).toBeGreaterThan(0),
+      );
+      await act(async () => {
+        await result.current.handleSlashCommand('/logtest');
+      });
+
+      expect(logSlashCommand).toHaveBeenCalledTimes(1);
+      expect(SlashCommandEvent).toHaveBeenCalledWith('logtest', undefined);
+    });
+
+    it('should log a slash command with a subcommand', async () => {
+      const result = setupProcessorHook(loggingTestCommands);
+      await waitFor(() =>
+        expect(result.current.slashCommands.length).toBeGreaterThan(0),
+      );
+      await act(async () => {
+        await result.current.handleSlashCommand('/logwithsub sub');
+      });
+
+      expect(logSlashCommand).toHaveBeenCalledTimes(1);
+      expect(SlashCommandEvent).toHaveBeenCalledWith('logwithsub', 'sub');
+    });
+
+    it('should log the command path when an alias is used', async () => {
+      const result = setupProcessorHook(loggingTestCommands);
+      await waitFor(() =>
+        expect(result.current.slashCommands.length).toBeGreaterThan(0),
+      );
+      await act(async () => {
+        await result.current.handleSlashCommand('/la');
+      });
+      expect(logSlashCommand).toHaveBeenCalledTimes(1);
+      expect(SlashCommandEvent).toHaveBeenCalledWith('logalias', undefined);
+    });
+
+    it('should not log for unknown commands', async () => {
+      const result = setupProcessorHook(loggingTestCommands);
+      await waitFor(() =>
+        expect(result.current.slashCommands.length).toBeGreaterThan(0),
+      );
+      await act(async () => {
+        await result.current.handleSlashCommand('/unknown');
+      });
+      expect(logSlashCommand).not.toHaveBeenCalled();
+    });
+  });
 });

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -13,6 +13,8 @@ import {
   Config,
   GitService,
   Logger,
+  logSlashCommand,
+  SlashCommandEvent,
   ToolConfirmationOutcome,
 } from '@google/gemini-cli-core';
 import { useSessionStats } from '../contexts/SessionContext.js';
@@ -233,6 +235,7 @@ export const useSlashCommandProcessor = (
         let currentCommands = commands;
         let commandToExecute: SlashCommand | undefined;
         let pathIndex = 0;
+        const canonicalPath: string[] = [];
 
         for (const part of commandPath) {
           // TODO: For better performance and architectural clarity, this two-pass
@@ -253,6 +256,7 @@ export const useSlashCommandProcessor = (
 
           if (foundCommand) {
             commandToExecute = foundCommand;
+            canonicalPath.push(foundCommand.name);
             pathIndex++;
             if (foundCommand.subCommands) {
               currentCommands = foundCommand.subCommands;
@@ -268,6 +272,17 @@ export const useSlashCommandProcessor = (
           const args = parts.slice(pathIndex).join(' ');
 
           if (commandToExecute.action) {
+            if (config) {
+              const resolvedCommandPath = canonicalPath;
+              const event = new SlashCommandEvent(
+                resolvedCommandPath[0],
+                resolvedCommandPath.length > 1
+                  ? resolvedCommandPath.slice(1).join(' ')
+                  : undefined,
+              );
+              logSlashCommand(config, event);
+            }
+
             const fullCommandContext: CommandContext = {
               ...commandContext,
               invocation: {