feat: add automated testing infrastructure, code cleanup, and update default model

.gitignore

@@ -66,6 +66,10 @@ dist/
 build/
 *.tsbuildinfo
 
+# AI/Claude working directories
+.ai/
+.claude/
+
 
 
 

.prettierignore

@@ -0,0 +1,19 @@
+# Dependencies
+node_modules/
+
+# AI/Claude directories
+.ai/
+.claude/
+
+# Build artifacts
+dist/
+coverage/
+
+# Cache
+.pytest_cache/
+
+# Lock files
+package-lock.json
+
+# Logs
+*.log

.prettierrc

@@ -0,0 +1,7 @@
+{
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "printWidth": 100,
+  "tabWidth": 2
+}

README.md

@@ -26,6 +26,15 @@ Visit [OpenRouter](https://openrouter.ai/) and get a key to use as a fallback pr
 You can set this key in your MCP settings under OPENROUTER_API_KEY, and it will trigger automatically if anything goes wrong with calling Cerebras.
 
 
+## Environment Variables
+
+| Variable | Description | Default |
+|----------|-------------|---------|
+| `CEREBRAS_API_KEY` | Your Cerebras API key (required) | - |
+| `CEREBRAS_MODEL` | Cerebras model to use | `zai-glm-4.7` |
+| `OPENROUTER_API_KEY` | OpenRouter API key (optional fallback) | - |
+| `OPENROUTER_MODEL` | OpenRouter model to use | `qwen/qwen3-coder` |
+
 ## 3. Run the Setup Wizard for Claude Code / Cursor / Cline / VS Code (Copilot)
 ```bash
 cerebras-mcp --config

docs/testing.md

@@ -0,0 +1,262 @@
+# Testing Guide
+
+This document covers the testing tools, processes, and conventions for the cerebras-code-mcp project.
+
+## Tools
+
+| Tool | Version | Purpose |
+|------|---------|---------|
+| [Vitest](https://vitest.dev/) | 4.x | Unit testing framework |
+| [ESLint](https://eslint.org/) | 9.x | Code linting |
+| [Prettier](https://prettier.io/) | 3.x | Code formatting |
+
+## npm Scripts
+
+### Testing
+
+```bash
+npm test                # Run unit tests once
+npm run test:watch      # Run unit tests in watch mode (re-runs on file changes)
+npm run test:coverage   # Run unit tests with coverage report
+npm run test:integration # Run integration tests (requires API keys)
+```
+
+### Linting
+
+```bash
+npm run lint          # Check for lint errors
+npm run lint:fix      # Auto-fix lint errors where possible
+```
+
+### Formatting
+
+```bash
+npm run format        # Format all files with Prettier
+npm run format:check  # Check if files are formatted (CI-friendly)
+```
+
+## Directory Structure
+
+Tests mirror the `src/` directory structure:
+
+```
+tests/
+├── api/
+│   ├── router/
+│   │   └── router.test.js
+│   ├── cerebras.test.js
+│   ├── openrouter.test.js
+│   └── rate-limiter.test.js
+├── config/
+│   └── constants.test.js
+├── formatting/
+│   ├── response-formatter.test.js
+│   └── syntax-highlighter.test.js
+├── server/
+│   ├── agent-spawner.test.js
+│   ├── mcp-server.test.js
+│   ├── planner.test.js
+│   ├── tool-handlers.test.js
+│   └── worker.test.js
+├── integration/
+│   ├── helpers/
+│   │   └── setup.js
+│   └── write.integration.test.js
+└── utils/
+    ├── code-cleaner.test.js
+    └── file-utils.test.js
+```
+
+## Writing Tests
+
+### File Naming
+
+- Unit test files: `*.test.js` under `tests/` mirroring `src/` structure
+- Integration test files: `*.integration.test.js` under `tests/integration/`
+- Example: `src/api/cerebras.js` → `tests/api/cerebras.test.js`
+
+### Test Structure
+
+```javascript
+import { describe, it, expect, vi } from 'vitest';
+import { myFunction } from '../../src/path/to/module.js';
+
+describe('myFunction', () => {
+  it('should do something specific', () => {
+    const result = myFunction(input);
+    expect(result).toBe(expectedOutput);
+  });
+
+  it('should handle edge case', () => {
+    expect(() => myFunction(badInput)).toThrow();
+  });
+});
+```
+
+### Common Assertions
+
+```javascript
+expect(value).toBe(expected)           // Strict equality
+expect(value).toEqual(expected)        // Deep equality
+expect(value).toBeTruthy()             // Truthy check
+expect(value).toBeNull()               // Null check
+expect(value).toBeUndefined()          // Undefined check
+expect(value).toContain(item)          // Array/string contains
+expect(fn).toThrow()                   // Throws error
+expect(fn).toThrow('message')          // Throws specific error
+```
+
+### Mocking
+
+```javascript
+import { vi } from 'vitest';
+
+// Mock a function
+const mockFn = vi.fn();
+mockFn.mockReturnValue('mocked');
+
+// Mock a module
+vi.mock('../../src/api/cerebras.js', () => ({
+  callCerebras: vi.fn().mockResolvedValue('mocked response'),
+}));
+
+// Spy on existing function
+const spy = vi.spyOn(object, 'method');
+```
+
+### Async Tests
+
+```javascript
+it('should handle async operations', async () => {
+  const result = await asyncFunction();
+  expect(result).toBe(expected);
+});
+
+it('should reject with error', async () => {
+  await expect(asyncFunction()).rejects.toThrow('error message');
+});
+```
+
+## Integration Tests
+
+Integration tests make real API calls and require provider API keys to be set as environment variables.
+
+### Prerequisites
+
+- `CEREBRAS_API_KEY` — required for Cerebras provider tests
+- `OPENROUTER_API_KEY` — required for OpenRouter provider tests
+- Both keys required for fallback tests (Cerebras → OpenRouter)
+
+Tests for a provider are automatically skipped if its API key is not set.
+
+### What's Tested
+
+| Test | Description |
+|------|-------------|
+| provider: cerebras | Direct Cerebras API call |
+| provider: openrouter | Direct OpenRouter API call |
+| fallback: cerebras → openrouter | Cerebras fails (invalid key), router falls back to OpenRouter |
+
+### Helpers (`tests/integration/helpers/setup.js`)
+
+- `forceProvider(provider)` — isolates a single provider by blanking the other's key
+- `forceFallback()` — sets an invalid Cerebras key (truthy but fails auth) to trigger the fallback path
+- `hasProvider(provider)` — checks if a provider's API key is available
+- `createTempDir()` — creates a temp directory for test file output, returns `{ dir, cleanup }`
+
+### Configuration
+
+Integration tests use a separate vitest config (`vitest.integration.config.js`) with a 30-second test timeout to accommodate real API latency.
+
+## Configuration Files
+
+### vitest.config.js (unit tests)
+
+```javascript
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    globals: true,
+    environment: 'node',
+    include: ['tests/**/*.test.js'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'html'],
+      include: ['src/**/*.js'],
+      exclude: ['src/index.js'],
+    },
+  },
+});
+```
+
+### vitest.integration.config.js (integration tests)
+
+```javascript
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    globals: true,
+    environment: 'node',
+    include: ['tests/integration/**/*.test.js'],
+    testTimeout: 30000,
+  },
+});
+```
+
+### eslint.config.js
+
+Uses ESLint 9 flat config format with:
+- Recommended JS rules
+- Prettier compatibility (disables conflicting rules)
+- Node.js globals
+- Custom rules for unused vars and const preference
+
+### .prettierrc
+
+```json
+{
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "printWidth": 100,
+  "tabWidth": 2
+}
+```
+
+## CI Integration
+
+For CI pipelines, use these commands:
+
+```bash
+# Check formatting (fails if not formatted)
+npm run format:check
+
+# Run linter (fails on errors)
+npm run lint
+
+# Run tests (fails on test failures)
+npm test
+
+# Run tests with coverage (optional)
+npm run test:coverage
+```
+
+## Coverage
+
+Run coverage report:
+
+```bash
+npm run test:coverage
+```
+
+This generates:
+- Terminal output with coverage summary
+- HTML report in `coverage/` directory
+
+Coverage targets:
+- Statements: 80%+
+- Branches: 80%+
+- Functions: 80%+
+- Lines: 80%+

eslint.config.js

@@ -0,0 +1,35 @@
+import js from "@eslint/js";
+import globals from "globals";
+import eslintConfigPrettier from "eslint-config-prettier";
+
+export default [
+  js.configs.recommended,
+  eslintConfigPrettier,
+  {
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: "module",
+      globals: {
+        ...globals.node,
+        ...globals.es2022,
+      },
+    },
+    rules: {
+      "no-unused-vars": ["error", { argsIgnorePattern: "^_", caughtErrorsIgnorePattern: "^_" }],
+      "no-console": "off",
+      "prefer-const": "error",
+      "no-var": "error",
+    },
+  },
+  {
+    ignores: [
+      "node_modules/",
+      ".ai/",
+      ".claude/",
+      "coverage/",
+      "dist/",
+      ".pytest_cache/",
+      "src/config/interactive-config.js",
+    ],
+  },
+];