Function collectServerCoverageMap

packages/test/src/lib/coverage.ts:190–249

(
  coverageDataDir: string,
  cwd: string,
  testFiles: Set<string>,
)

}

export async function collectServerCoverageMap(
  coverageDataDir: string,
  cwd: string,
  testFiles: Set<string>,
): Promise<CoverageMap | null> {
  let { createCoverageMap } = getIstanbul()
  let coverageMap = createCoverageMap({})
  let converted = 0

  let files: string[]
  try {
    files = (await fsp.readdir(coverageDataDir)).filter(
      (f) => f.startsWith('coverage-') && f.endsWith('.json'),
    )
  } catch {
    return null
  }

  for (let file of files) {
    let data = JSON.parse(await fsp.readFile(path.join(coverageDataDir, file), 'utf-8'))
    let scriptCoverages: Array<{ url: string; functions: any[] }> = data.result ?? []

    for (let entry of scriptCoverages) {
      if (!entry.url.startsWith('file://')) continue

      let filePath: string
      try {
        filePath = fileURLToPath(entry.url)
      } catch {
        continue
      }

      if (
        !filePath ||
        !['.ts', '.tsx'].includes(path.extname(filePath)) ||
        shouldExcludeFromCoverage(filePath, cwd, testFiles)
      ) {
        continue
      }

      try {
        // For server unit tests, we transform the TS with a module loader and V8 tracks
        // coverage using byte offsets from the transformed JS. Re-transform with the
        // same `esbuild` call here so offsets align, then pass the result with its
        // inline source map to v8-to-istanbul.
        let tsSource = await fsp.readFile(filePath, 'utf-8')
        let { code } = await transformTypeScript(tsSource, filePath)
        let success = await addV8EntryToCoverageMap(coverageMap, filePath, entry.functions, code)
        if (success) converted++
      } catch {
        // Skip files that can't be converted
      }
    }
  }

  // Clean up raw V8 coverage JSON files now that we've processed them
  //await Promise.all(files.map((f) => fsp.rm(path.join(coverageDataDir, f), { force: true })))