Gartner 评定 OpenAI 为企业级编码 Agent 领导者：Codex 落地实践与选型思考

# 安装 Codex CLI（当前为 npm 包）
npm install -g @openai/codex

# 设置 API Key
export OPENAI_API_KEY="sk-xxxxxxxxxxxxxxxx"

# 在项目根目录执行任务委托
# --sandbox 确保代码在隔离环境执行
# --diff-only 只输出 diff，不自动写入文件
codex \
  --sandbox \
  --diff-only \
  "为 src/calculator.py 中的所有公共函数添加类型标注，\
   并在 tests/ 下生成对应的 pytest 单元测试文件 test_calculator.py"

--- a/src/calculator.py
+++ b/src/calculator.py
@@ -1,8 +1,8 @@
-def add(a, b):
+def add(a: float, b: float) -> float:
     return a + b

-def divide(a, b):
+def divide(a: float, b: float) -> float:
     if b == 0:
         raise ValueError("division by zero")
     return a / b

--- /dev/null
+++ b/tests/test_calculator.py
@@ -0,0 +1,15 @@
+import pytest
+from src.calculator import add, divide
+
+def test_add():
+    assert add(2.0, 3.0) == 5.0
+
+def test_add_negative():
+    assert add(-1.0, -2.0) == -3.0
+
+def test_divide():
+    assert divide(10.0, 2.0) == 5.0
+
+def test_divide_by_zero():
+    with pytest.raises(ValueError):
+        divide(1.0, 0.0)

# 应用 diff 到本地文件
codex apply last

import os
import openai

client = openai.OpenAI(api_key=os.environ["OPENAI_API_KEY"])

def generate_tests_for_pr(diff_text: str, file_content: str) -> str:
    """根据 PR diff 和当前文件内容，生成补充测试代码。"""
    response = client.responses.create(
        model="codex-mini-latest",
        instructions=(
            "你是一个企业级编码助手。根据提供的 diff 和源文件内容，"
            "生成 pytest 测试代码，覆盖 diff 中新增或修改的逻辑。"
            "只输出测试代码，不要输出其他解释。"
        ),
        input=[
            {"role": "user", "content": f"PR diff:\n{diff_text}\n\n源文件:\n{file_content}"}
        ],
    )
    return response.output_text

# 示例：从 CI 环境获取 PR diff
diff = os.environ.get("PR_DIFF", "")
source = open("src/calculator.py").read()

test_code = generate_tests_for_pr(diff, source)
print(test_code)

# 写入测试文件
with open("tests/test_calculator_auto.py", "w") as f:
    f.write(test_code)

name: auto-test-gen
on:
  pull_request:
    types: [opened, synchronize]

jobs:
  generate-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: pip install openai pytest
      - name: Fetch PR diff
        run: |
          PR_DIFF=$(curl -s -H "Authorization: token ${{ github.token }}" \
            "${{ github.api_url }}/repos/${{ github.repository }}/pulls/${{ github.event.number }}" \
            | jq -r '.diff_url' | xargs curl -s)
          echo "PR_DIFF=$PR_DIFF" >> $GITHUB_ENV
      - name: Run test generation
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
        run: python scripts/generate_tests.py
      - name: Run generated tests
        run: pytest tests/test_calculator_auto.py -v