feat: implement code action provider for VS Code integration

src/core/__tests__/CodeActionProvider.test.ts

@@ -0,0 +1,145 @@
+import * as vscode from 'vscode';
+import { CodeActionProvider } from '../CodeActionProvider';
+
+// Mock VSCode API
+jest.mock('vscode', () => ({
+    CodeAction: jest.fn().mockImplementation((title, kind) => ({
+        title,
+        kind,
+        command: undefined
+    })),
+    CodeActionKind: {
+        QuickFix: { value: 'quickfix' },
+        RefactorRewrite: { value: 'refactor.rewrite' }
+    },
+    Range: jest.fn().mockImplementation((startLine, startChar, endLine, endChar) => ({
+        start: { line: startLine, character: startChar },
+        end: { line: endLine, character: endChar }
+    })),
+    Position: jest.fn().mockImplementation((line, character) => ({
+        line,
+        character
+    })),
+    workspace: {
+        getWorkspaceFolder: jest.fn()
+    },
+    DiagnosticSeverity: {
+        Error: 0,
+        Warning: 1,
+        Information: 2,
+        Hint: 3
+    }
+}));
+
+describe('CodeActionProvider', () => {
+    let provider: CodeActionProvider;
+    let mockDocument: any;
+    let mockRange: any;
+    let mockContext: any;
+
+    beforeEach(() => {
+        provider = new CodeActionProvider();
+        
+        // Mock document
+        mockDocument = {
+            getText: jest.fn(),
+            lineAt: jest.fn(),
+            lineCount: 10,
+            uri: { fsPath: '/test/file.ts' }
+        };
+
+        // Mock range
+        mockRange = new vscode.Range(0, 0, 0, 10);
+
+        // Mock context
+        mockContext = {
+            diagnostics: []
+        };
+    });
+
+    describe('getEffectiveRange', () => {
+        it('should return selected text when available', () => {
+            mockDocument.getText.mockReturnValue('selected text');
+            
+            const result = (provider as any).getEffectiveRange(mockDocument, mockRange);
+            
+            expect(result).toEqual({
+                range: mockRange,
+                text: 'selected text'
+            });
+        });
+
+        it('should return null for empty line', () => {
+            mockDocument.getText.mockReturnValue('');
+            mockDocument.lineAt.mockReturnValue({ text: '', lineNumber: 0 });
+            
+            const result = (provider as any).getEffectiveRange(mockDocument, mockRange);
+            
+            expect(result).toBeNull();
+        });
+    });
+
+    describe('getFilePath', () => {
+        it('should return relative path when in workspace', () => {
+            const mockWorkspaceFolder = {
+                uri: { fsPath: '/test' }
+            };
+            (vscode.workspace.getWorkspaceFolder as jest.Mock).mockReturnValue(mockWorkspaceFolder);
+            
+            const result = (provider as any).getFilePath(mockDocument);
+            
+            expect(result).toBe('file.ts');
+        });
+
+        it('should return absolute path when not in workspace', () => {
+            (vscode.workspace.getWorkspaceFolder as jest.Mock).mockReturnValue(null);
+            
+            const result = (provider as any).getFilePath(mockDocument);
+            
+            expect(result).toBe('/test/file.ts');
+        });
+    });
+
+    describe('provideCodeActions', () => {
+        beforeEach(() => {
+            mockDocument.getText.mockReturnValue('test code');
+            mockDocument.lineAt.mockReturnValue({ text: 'test code', lineNumber: 0 });
+        });
+
+        it('should provide explain and improve actions by default', () => {
+            const actions = provider.provideCodeActions(mockDocument, mockRange, mockContext);
+            
+            expect(actions).toHaveLength(2);
+            expect((actions as any)[0].title).toBe('Roo Cline: Explain Code');
+            expect((actions as any)[1].title).toBe('Roo Cline: Improve Code');
+        });
+
+        it('should provide fix action when diagnostics exist', () => {
+            mockContext.diagnostics = [{
+                message: 'test error',
+                severity: vscode.DiagnosticSeverity.Error,
+                range: mockRange
+            }];
+            
+            const actions = provider.provideCodeActions(mockDocument, mockRange, mockContext);
+            
+            expect(actions).toHaveLength(3);
+            expect((actions as any).some((a: any) => a.title === 'Roo Cline: Fix Code')).toBe(true);
+        });
+
+        it('should handle errors gracefully', () => {
+            const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+            mockDocument.getText.mockImplementation(() => {
+                throw new Error('Test error');
+            });
+            mockDocument.lineAt.mockReturnValue({ text: 'test', lineNumber: 0 });
+            
+            const actions = provider.provideCodeActions(mockDocument, mockRange, mockContext);
+            
+            expect(actions).toEqual([]);
+            expect(consoleErrorSpy).toHaveBeenCalledWith('Error getting effective range:', expect.any(Error));
+            
+            consoleErrorSpy.mockRestore();
+        });
+    });
+});