cc-haha/scripts/quality-gate/coverage.test.ts

import { describe, expect, test } from 'bun:test'
import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import {
  collectServerTestFiles,
  evaluateChangedLineCoverage,
  evaluateThresholds,
  parseChangedLinesFromDiff,
  parseLcov,
  prefixRelativeLcovSourcePaths,
  rangeContainsMergeCommit,
} from './coverage'

describe('coverage gate helpers', () => {
  test('parses lcov totals into percentages', () => {
    const summary = parseLcov([
      'TN:',
      'SF:src/a.ts',
      'FNF:4',
      'FNH:3',
      'BRF:10',
      'BRH:7',
      'LF:20',
      'LH:18',
      'end_of_record',
      'SF:src/b.ts',
      'FNF:1',
      'FNH:1',
      'LF:10',
      'LH:5',
      'end_of_record',
    ].join('\n'))

    expect(summary.lines.pct).toBe(76.67)
    expect(summary.functions.pct).toBe(80)
    expect(summary.branches.pct).toBe(70)
  })

  test('filters lcov records to an explicit source scope', () => {
    const summary = parseLcov([
      'TN:',
      'SF:/repo/src/server/routes.ts',
      'LF:10',
      'LH:8',
      'FNF:2',
      'FNH:2',
      'end_of_record',
      'SF:/repo/desktop/src-tauri/target/generated.js',
      'LF:100',
      'LH:0',
      'FNF:10',
      'FNH:0',
      'end_of_record',
    ].join('\n'), {
      rootDir: '/repo',
      scope: {
        id: 'server-api',
        title: 'Server/API',
        includePrefixes: ['src/server/'],
      },
    })

    expect(summary.lines.pct).toBe(80)
    expect(summary.functions.pct).toBe(100)
  })

  test('prefixes package-relative lcov source paths for changed-line coverage', () => {
    const lcov = prefixRelativeLcovSourcePaths([
      'TN:',
      'SF:src/stores/updateStore.ts',
      'LF:1',
      'LH:1',
      'end_of_record',
      'SF:/repo/desktop/src/main.tsx',
      'LF:1',
      'LH:0',
      'end_of_record',
      'SF:desktop/src/App.tsx',
      'LF:1',
      'LH:1',
      'end_of_record',
    ].join('\n'), 'desktop')

    expect(lcov).toContain('SF:desktop/src/stores/updateStore.ts')
    expect(lcov).toContain('SF:/repo/desktop/src/main.tsx')
    expect(lcov).toContain('SF:desktop/src/App.tsx')
  })

  test('evaluates changed executable line coverage', () => {
    const changedLines = parseChangedLinesFromDiff([
      'diff --git a/src/server/routes.ts b/src/server/routes.ts',
      '--- a/src/server/routes.ts',
      '+++ b/src/server/routes.ts',
      '@@ -10,0 +11,2 @@',
      '+const covered = true',
      '+const uncovered = false',
    ].join('\n'))

    const failures = evaluateChangedLineCoverage(
      changedLines,
      new Map([
        ['src/server/routes.ts', {
          suiteId: 'server-api',
          executableLines: new Set([11, 12]),
          coveredLines: new Set([11]),
        }],
      ]),
      [{
        id: 'server-api',
        title: 'Server/API',
        includePrefixes: ['src/server/'],
      }],
      90,
    ).failures

    expect(failures).toEqual(['changed-lines: coverage 50% is below minimum 90%'])
  })

  test('excludes non-instrumented desktop styles from changed-line coverage', () => {
    const changedLines = parseChangedLinesFromDiff([
      'diff --git a/desktop/src/theme/globals.css b/desktop/src/theme/globals.css',
      '--- a/desktop/src/theme/globals.css',
      '+++ b/desktop/src/theme/globals.css',
      '@@ -10,0 +11,2 @@',
      '+.sidebar {',
      '+  color: var(--color-text-primary);',
      '+}',
      'diff --git a/desktop/src/main.tsx b/desktop/src/main.tsx',
      '--- a/desktop/src/main.tsx',
      '+++ b/desktop/src/main.tsx',
      '@@ -20,0 +21,1 @@',
      '+bootstrapDesktopApp()',
    ].join('\n'))

    const result = evaluateChangedLineCoverage(
      changedLines,
      new Map([
        ['desktop/src/main.tsx', {
          suiteId: 'desktop',
          executableLines: new Set([21]),
          coveredLines: new Set([21]),
        }],
      ]),
      [{
        id: 'desktop',
        title: 'Desktop',
        includePrefixes: ['desktop/src/'],
        excludeSuffixes: ['.css'],
      }],
      90,
    )

    expect(result.files).toEqual([{
      file: 'desktop/src/main.tsx',
      suiteId: 'desktop',
      covered: 1,
      total: 1,
      pct: 100,
    }])
    expect(result.failures).toEqual([])
  })

  test('reports minimum threshold failures', () => {
    const failures = evaluateThresholds([
      {
        id: 'root-server',
        title: 'Root',
        status: 'passed',
        command: ['bun', 'test'],
        durationMs: 1,
        logPath: 'coverage.log',
        summary: {
          lines: { total: 100, covered: 79, pct: 79 },
          functions: { total: 10, covered: 9, pct: 90 },
          branches: { total: 10, covered: 8, pct: 80 },
          statements: { total: 100, covered: 79, pct: 79 },
        },
      },
    ], {
      schemaVersion: 1,
      minimums: {
        'root-server': {
          lines: 80,
        },
      },
    })

    expect(failures).toEqual(['root-server: lines coverage 79% is below minimum 80%'])
  })

  test('treats failed suite execution as a coverage failure', () => {
    const failures = evaluateThresholds([
      {
        id: 'desktop',
        title: 'Desktop',
        status: 'failed',
        command: ['bun', 'run', 'test'],
        durationMs: 1,
        logPath: 'coverage.log',
        error: 'coverage command exited with 1',
      },
    ], {
      schemaVersion: 1,
      minimums: {},
    })

    expect(failures).toEqual(['desktop: coverage command exited with 1'])
  })

  test('collects non-quarantined server tests when review windows have expired', () => {
    const root = mkdtempSync(join(tmpdir(), 'cc-haha-coverage-'))
    try {
      mkdirSync(join(root, 'src/server/__tests__'), { recursive: true })
      mkdirSync(join(root, 'src/tools'), { recursive: true })
      mkdirSync(join(root, 'src/utils'), { recursive: true })
      writeFileSync(join(root, 'src/server/__tests__/active.test.ts'), '')
      writeFileSync(join(root, 'src/server/__tests__/quarantined.test.ts'), '')

      const files = collectServerTestFiles(root, {
        quarantined: [
          {
            id: 'server:expired',
            path: 'src/server/__tests__/quarantined.test.ts',
            reason: 'Known instability under review.',
            owner: 'maintainers',
            reviewAfter: '2026-01-01',
            exitCriteria: 'Make deterministic or remove from quarantine.',
          },
        ],
      })

      expect(files).toEqual(['src/server/__tests__/active.test.ts'])
    } finally {
      rmSync(root, { recursive: true, force: true })
    }
  })

  test('does not require every suite to exist in the ratchet baseline', () => {
    const failures = evaluateThresholds([
      {
        id: 'new-suite',
        title: 'New suite',
        status: 'passed',
        command: ['bun', 'test'],
        durationMs: 1,
        logPath: 'coverage.log',
        summary: {
          lines: { total: 100, covered: 90, pct: 90 },
          functions: { total: 10, covered: 9, pct: 90 },
          branches: { total: 10, covered: 8, pct: 80 },
          statements: { total: 100, covered: 90, pct: 90 },
        },
      },
    ], {
      schemaVersion: 1,
      minimums: {
        'new-suite': {
          branches: 85,
        },
      },
      ratchet: {
        baselinePath: 'scripts/quality-gate/coverage-baseline.json',
        allowedDropPercent: 0,
      },
    })

    expect(failures).toEqual(['new-suite: branches coverage 80% is below minimum 85%'])
  })

  test('detects a merge commit in the base..HEAD range (upstream-sync exemption)', () => {
    const repo = mkdtempSync(join(tmpdir(), 'cc-haha-coverage-merge-'))
    const git = (...args: string[]) => {
      const proc = Bun.spawnSync(['git', ...args], { cwd: repo, stdout: 'pipe', stderr: 'pipe' })
      if (proc.exitCode !== 0) {
        throw new Error(`git ${args.join(' ')} failed: ${new TextDecoder().decode(proc.stderr)}`)
      }
    }
    try {
      git('init', '-b', 'main')
      git('config', 'user.email', 'test@example.com')
      git('config', 'user.name', 'Test')
      writeFileSync(join(repo, 'base.txt'), 'base\n')
      git('add', '.')
      git('commit', '-m', 'base')

      // A linear feature commit on top of main: no merge in range.
      git('checkout', '-b', 'feature')
      writeFileSync(join(repo, 'feature.txt'), 'feature\n')
      git('add', '.')
      git('commit', '-m', 'feature work')
      expect(rangeContainsMergeCommit(repo, 'main')).toBe(false)

      // Bring in a side branch via a merge commit: now the range has a merge.
      git('checkout', 'main')
      git('checkout', '-b', 'side')
      writeFileSync(join(repo, 'side.txt'), 'side\n')
      git('add', '.')
      git('commit', '-m', 'side work')
      git('checkout', 'feature')
      git('merge', '--no-ff', 'side', '-m', 'merge side into feature')
      expect(rangeContainsMergeCommit(repo, 'main')).toBe(true)
    } finally {
      rmSync(repo, { recursive: true, force: true })
    }
  })
})