testing

name	testing
description	Guide for writing tests in Agent Lens. Use when creating unit tests, integration tests, or setting up test infrastructure.

Testing Patterns — Agent Lens

TDD workflow

1. Write a failing test (red)
2. Write minimal code to pass (green)
3. Refactor while keeping tests green

Vitest setup

• Config: vitest.config.ts (globals enabled, includes src/**/*.test.ts and webview/**/*.test.ts)
• Run all: npm test
• Run one file: npx vitest run src/parsers/agentParser.test.ts
• Watch mode: npm run test:watch

File conventions

• Tests are co-located: src/parsers/foo.ts → src/parsers/foo.test.ts
• Use describe / it blocks
• Use expect assertions
• Vitest globals are enabled (no imports needed for describe, it, expect)

What to test

Layer	What to test	Example file
Parsers	Pure function input/output, edge cases, malformed input	agentParser.test.ts
Analyzers	Graph construction, metrics aggregation, edge cases	graphBuilder.test.ts
Detectors	Detection logic for agents, skills, tools, MCP servers	detectors.test.ts
Layout	D3-DAG layout algorithm, cycle handling	webview/layout.test.ts

Mocking

• Mock external dependencies (filesystem, VS Code API), not internal logic
• For parsers: pass input strings directly, no mocking needed
• For providers: mock fs and vscode.workspace at boundaries

Common patterns

describe("parserName", () => {
  it("should parse valid input", () => {
    const result = parseAgent(validMarkdown);
    expect(result.name).toBe("expected");
  });

  it("should handle missing frontmatter", () => {
    const result = parseAgent("no frontmatter here");
    expect(result.name).toBe("");
  });
});