Current deno coverage interface is not compatible with istanbul

[loynoir]

Comparison

• c8 generate coverage, able to integrate with istanbul without hardcode

• playwright generate coverage compatible with istanbul https://playwright.dev/docs/api/class-coverage

• When integrate deno coverage with istanbul, need to hard code. Else geneate wrong report.

Interface Comparison

interface CoverageC8 {
  result: Array<{
    scriptId: `${number}`
    url: `${string}:${string}`
    functions: Array<{
      functionName: string
      ranges: Array<{
        startOffset: number
        endOffset: number
        count: number
      }>
      isBlockCoverage: boolean
    }>
  }>
  timestamp: number
  'source-map-cache': Record<
    `${string}://${string}`,
    {
      lineLengths: [number, number, number]
      data: {
        version: 3
        file?: null
        mappings: string
        names: never[]
        sources: [`${string}://${string}`]
        sourcesContent: [string]
        sourceRoot: ''
      }
      url: null
      sourceURL: null
    }
  >
}

interface CoveragePlaywright {
  url: `${string}://${string}`
  scriptId: `${number}`
  source: string
  functions: Array<{
    functionName: string
    isBlockCoverage: boolean
    ranges: Array<{
      startOffset: number
      endOffset: number
      count: number
    }>
  }>
}

interface CoverageDeno {
  scriptId: `${number}`
  url: `${string}://${string}`
  functions: Array<{
    functionName: string
    isBlockCoverage: boolean
    ranges: Array<{
      startOffset: number
      endOffset: number
      count: number
    }>
  }>
}

Reproduce

Adapt from https://playwright.dev/docs/api/class-coverage, which have similar interface like deno coverage.

When use below code, generate wrong report.

          const converter = v8toIstanbul(entry.url, 0, {
            source: entry.source ?? (await read(entry.url))
          })

Workaround

Adapt from https://playwright.dev/docs/api/class-coverage, which have similar interface like deno coverage.

To generate correct report, must use hard code:

• make sure using same typescript version with deno

• make sure using same typescript config with deno

          const converter = v8toIstanbul(entry.url, 0, {
            source: entry.source ?? ts.transpile(await read(entry.url), compileOptions, entry.url)
          })

Suggestion

• Or add .source which represent the js after compiled should work. So, user don't need to hard code typescript version and config, to ensure .source is identical with deno coverage .range.

• Or use interface CoverageC8, with provide .source-map-cache, and should be better than CoveragePlaywright

[loynoir]

Reproduce

          const converter = v8toIstanbul(entry.url, 0, {
            source: entry.source ?? (await read(entry.url))
          })

Workaround

          const converter = v8toIstanbul(entry.url, 0, {
            source: entry.source ?? ts.transpile(await read(entry.url), compileOptions, entry.url)
          })