精准测试与变更影响分析

<!-- pom.xml: JaCoCo 覆盖率收集 -->
<plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.8.12</version>
    <executions>
        <execution>
            <id>prepare-agent</id>
            <goals>
                <goal>prepare-agent</goal>
            </goals>
        </execution>
        <execution>
            <id>report</id>
            <phase>test</phase>
            <goals>
                <goal>report</goal>
            </goals>
        </execution>
    </executions>
</plugin>

"""
精准测试用例选择器
输入：Git Diff + 覆盖率数据库（3.2 节构建的"测试ID → 覆盖的文件:行号"映射）
输出：需要执行的测试用例列表
"""
import json
import re
import subprocess
import sys
from collections import defaultdict

DIFF_RE = re.compile(r"^\+\+\+ b/(.+)$")
HUNK_RE = re.compile(r"^@@ -\d+(?:,\d+)? \+(\d+)(?:,(\d+))? @@")

def get_changed_lines():
    """获取 Git 变更的文件与行号"""
    diff = subprocess.check_output(
        ["git", "diff", "--unified=0", "origin/main...HEAD"],
        text=True
    )
    changed = defaultdict(set)
    current_file = None

    for line in diff.split("\n"):
        match = DIFF_RE.match(line)
        if match:
            current_file = match.group(1)
        elif current_file:
            hunk = HUNK_RE.match(line)
            if hunk:
                # 解析 @@ -old,count +new,count @@，记录新增区间的每一行
                start = int(hunk.group(1))
                count = int(hunk.group(2) or "1")
                changed[current_file].update(range(start, start + count))

    return changed

def load_coverage_data(db_path):
    """加载覆盖率数据库，构建测试→代码映射"""
    with open(db_path) as f:
        coverage_db = json.load(f)

    test_to_code = {
        test_id: {
            file_path: set(lines)
            for file_path, lines in files.items()
        }
        for test_id, files in coverage_db.items()
    }
    return test_to_code

def select_precision_tests(changed_lines, test_to_code):
    """选择覆盖了变更代码的测试用例"""
    selected = set()
    for test_id, files in test_to_code.items():
        for file_path, lines in files.items():
            if changed_lines.get(file_path, set()) & lines:
                selected.add(test_id)
                break
    return selected

def main():
    changed = get_changed_lines()
    if not changed:
        print("无代码变更，跳过测试")
        sys.exit(0)

    test_to_code = load_coverage_data("coverage-map.json")
    selected = select_precision_tests(changed, test_to_code)

    if not selected:
        print("变更代码未被任何测试覆盖，建议补充测试!")
        sys.exit(1)

    print(f"精准选择 {len(selected)} 个测试用例:")
    for test_id in sorted(selected):
        print(f"  {test_id}")

    # 输出给 pytest 执行
    with open("precision-tests.txt", "w") as f:
        for test_id in sorted(selected):
            f.write(test_id + "\n")

if __name__ == "__main__":
    main()

name: Precision Testing
on:
  pull_request:
    branches: [main]

jobs:
  precision-test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0  # 需要完整历史以计算 diff

      - uses: actions/setup-python@v5
        with:
          python-version: '3.13'

      - name: 下载上次构建的覆盖率数据
        uses: actions/download-artifact@v4
        with:
          name: coverage-baseline
          path: .

      - name: 精准选择测试用例
        id: select
        run: |
          python scripts/precision_test_selector.py
          echo "count=$(wc -l < precision-tests.txt)" >> $GITHUB_OUTPUT

      - name: 执行精准测试
        if: steps.select.outputs.count != '0'
        run: |
          pytest $(cat precision-tests.txt | tr '\n' ' ') \
            --cov=src --cov-report=xml

      - name: 上传更新后的覆盖率数据
        uses: actions/upload-artifact@v4
        with:
          name: coverage-baseline
          path: coverage-map.json