coverage.ts

import { test as base, expect } from '@playwright/test'
import * as fs from 'fs/promises'
import * as path from 'path'

const coverageDir = path.resolve(process.cwd(), '.nyc_output')

interface CoverageWindow extends Window {
  __coverage__?: Record<string, unknown>
}

const sanitize = (value: string) => {
  return value.replace(/[^a-zA-Z0-9_-]+/g, '_')
}

const test = base.extend<{ _collectCoverage: void }>({
  _collectCoverage: [
    async ({ page }, use, testInfo) => {
      await use()

      if (process.env.COVERAGE !== '1') {
        return
      }

      try {
        const coverage = await page.evaluate(
          () => (window as unknown as CoverageWindow).__coverage__ ?? null,
        )

        if (!coverage) {
          return
        }

        await fs.mkdir(coverageDir, { recursive: true })

        const title = sanitize(testInfo.titlePath.join('-'))
        const fileName = `${testInfo.project.name}-${title}.json`
        const filePath = path.join(coverageDir, fileName)

        await fs.writeFile(filePath, JSON.stringify(coverage), 'utf8')
      } catch {
        // Ignore coverage collection failures to avoid masking test results.
      }
    },
    { auto: true },
  ],
})

export { expect, test }