1 files changed, 223 insertions, 0 deletions
diff --git a/packages/cli/src/ui/components/InputPrompt.test.tsx b/packages/cli/src/ui/components/InputPrompt.test.tsx
index 7d0cfcbb..6f3f996d 100644
--- a/packages/cli/src/ui/components/InputPrompt.test.tsx
+++ b/packages/cli/src/ui/components/InputPrompt.test.tsx
@@ -8,10 +8,12 @@ import { render } from 'ink-testing-library';
 import { InputPrompt, InputPromptProps } from './InputPrompt.js';
 import type { TextBuffer } from './shared/text-buffer.js';
 import { Config } from '@google/gemini-cli-core';
+import { CommandContext, SlashCommand } from '../commands/types.js';
 import { vi } from 'vitest';
 import { useShellHistory } from '../hooks/useShellHistory.js';
 import { useCompletion } from '../hooks/useCompletion.js';
 import { useInputHistory } from '../hooks/useInputHistory.js';
+import { createMockCommandContext } from '../../test-utils/mockCommandContext.js';
 
 vi.mock('../hooks/useShellHistory.js');
 vi.mock('../hooks/useCompletion.js');
@@ -21,12 +23,38 @@ type MockedUseShellHistory = ReturnType<typeof useShellHistory>;
 type MockedUseCompletion = ReturnType<typeof useCompletion>;
 type MockedUseInputHistory = ReturnType<typeof useInputHistory>;
 
+const mockSlashCommands: SlashCommand[] = [
+  { name: 'clear', description: 'Clear screen', action: vi.fn() },
+  {
+    name: 'memory',
+    description: 'Manage memory',
+    subCommands: [
+      { name: 'show', description: 'Show memory', action: vi.fn() },
+      { name: 'add', description: 'Add to memory', action: vi.fn() },
+      { name: 'refresh', description: 'Refresh memory', action: vi.fn() },
+    ],
+  },
+  {
+    name: 'chat',
+    description: 'Manage chats',
+    subCommands: [
+      {
+        name: 'resume',
+        description: 'Resume a chat',
+        action: vi.fn(),
+        completion: async () => ['fix-foo', 'fix-bar'],
+      },
+    ],
+  },
+];
+
 describe('InputPrompt', () => {
   let props: InputPromptProps;
   let mockShellHistory: MockedUseShellHistory;
   let mockCompletion: MockedUseCompletion;
   let mockInputHistory: MockedUseInputHistory;
   let mockBuffer: TextBuffer;
+  let mockCommandContext: CommandContext;
 
   const mockedUseShellHistory = vi.mocked(useShellHistory);
   const mockedUseCompletion = vi.mocked(useCompletion);
@@ -35,6 +63,8 @@ describe('InputPrompt', () => {
   beforeEach(() => {
     vi.resetAllMocks();
 
+    mockCommandContext = createMockCommandContext();
+
     mockBuffer = {
       text: '',
       cursor: [0, 0],
@@ -99,12 +129,15 @@ describe('InputPrompt', () => {
         getTargetDir: () => '/test/project/src',
       } as unknown as Config,
       slashCommands: [],
+      commandContext: mockCommandContext,
       shellModeActive: false,
       setShellModeActive: vi.fn(),
       inputWidth: 80,
       suggestionsWidth: 80,
       focus: true,
     };
+
+    props.slashCommands = mockSlashCommands;
   });
 
   const wait = (ms = 50) => new Promise((resolve) => setTimeout(resolve, ms));
@@ -184,4 +217,194 @@ describe('InputPrompt', () => {
     expect(props.onSubmit).toHaveBeenCalledWith('some text');
     unmount();
   });
+
+  it('should complete a partial parent command and add a space', async () => {
+    // SCENARIO: /mem -> Tab
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [{ label: 'memory', value: 'memory', description: '...' }],
+      activeSuggestionIndex: 0,
+    });
+    props.buffer.setText('/mem');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\t'); // Press Tab
+    await wait();
+
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory ');
+    unmount();
+  });
+
+  it('should append a sub-command when the parent command is already complete with a space', async () => {
+    // SCENARIO: /memory  -> Tab (to accept 'add')
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [
+        { label: 'show', value: 'show' },
+        { label: 'add', value: 'add' },
+      ],
+      activeSuggestionIndex: 1, // 'add' is highlighted
+    });
+    props.buffer.setText('/memory ');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\t'); // Press Tab
+    await wait();
+
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory add ');
+    unmount();
+  });
+
+  it('should handle the "backspace" edge case correctly', async () => {
+    // SCENARIO: /memory  -> Backspace -> /memory -> Tab (to accept 'show')
+    // This is the critical bug we fixed.
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [
+        { label: 'show', value: 'show' },
+        { label: 'add', value: 'add' },
+      ],
+      activeSuggestionIndex: 0, // 'show' is highlighted
+    });
+    // The user has backspaced, so the query is now just '/memory'
+    props.buffer.setText('/memory');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\t'); // Press Tab
+    await wait();
+
+    // It should NOT become '/show '. It should correctly become '/memory show '.
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory show ');
+    unmount();
+  });
+
+  it('should complete a partial argument for a command', async () => {
+    // SCENARIO: /chat resume fi- -> Tab
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [{ label: 'fix-foo', value: 'fix-foo' }],
+      activeSuggestionIndex: 0,
+    });
+    props.buffer.setText('/chat resume fi-');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\t'); // Press Tab
+    await wait();
+
+    expect(props.buffer.setText).toHaveBeenCalledWith('/chat resume fix-foo ');
+    unmount();
+  });
+
+  it('should autocomplete on Enter when suggestions are active, without submitting', async () => {
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [{ label: 'memory', value: 'memory' }],
+      activeSuggestionIndex: 0,
+    });
+    props.buffer.setText('/mem');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\r');
+    await wait();
+
+    // The app should autocomplete the text, NOT submit.
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory ');
+
+    expect(props.onSubmit).not.toHaveBeenCalled();
+    unmount();
+  });
+
+  it('should complete a command based on its altName', async () => {
+    // Add a command with an altName to our mock for this test
+    props.slashCommands.push({
+      name: 'help',
+      altName: '?',
+      description: '...',
+    });
+
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [{ label: 'help', value: 'help' }],
+      activeSuggestionIndex: 0,
+    });
+    props.buffer.setText('/?');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\t'); // Press Tab
+    await wait();
+
+    expect(props.buffer.setText).toHaveBeenCalledWith('/help ');
+    unmount();
+  });
+
+  // ADD this test for defensive coverage
+
+  it('should not submit on Enter when the buffer is empty or only contains whitespace', async () => {
+    props.buffer.setText('   '); // Set buffer to whitespace
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\r'); // Press Enter
+    await wait();
+
+    expect(props.onSubmit).not.toHaveBeenCalled();
+    unmount();
+  });
+
+  it('should submit directly on Enter when a complete leaf command is typed', async () => {
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: false,
+    });
+    props.buffer.setText('/clear');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\r');
+    await wait();
+
+    expect(props.onSubmit).toHaveBeenCalledWith('/clear');
+    expect(props.buffer.setText).not.toHaveBeenCalledWith('/clear ');
+    unmount();
+  });
+
+  it('should autocomplete an @-path on Enter without submitting', async () => {
+    mockedUseCompletion.mockReturnValue({
+      ...mockCompletion,
+      showSuggestions: true,
+      suggestions: [{ label: 'index.ts', value: 'index.ts' }],
+      activeSuggestionIndex: 0,
+    });
+    props.buffer.setText('@src/components/');
+
+    const { stdin, unmount } = render(<InputPrompt {...props} />);
+    await wait();
+
+    stdin.write('\r');
+    await wait();
+
+    expect(props.buffer.replaceRangeByOffset).toHaveBeenCalled();
+    expect(props.onSubmit).not.toHaveBeenCalled();
+    unmount();
+  });
 });