test/lib/internal/test_runner/reporter/tap.js

Node.js 18's node:test, as an npm package

// https://github.com/nodejs/node/blob/2f38c74e263ed2e7f3b087efb9adee2442dd25c4/lib/internal/test_runner/tap_stream.js

'use strict'

const {
  ArrayPrototypeForEach,
  ArrayPrototypeJoin,
  ArrayPrototypePush,
  ObjectEntries,
  RegExpPrototypeSymbolReplace,
  SafeMap,
  StringPrototypeReplaceAll,
  StringPrototypeSplit,
  StringPrototypeRepeat
} = require('#internal/per_context/primordials')
const { inspectWithNoCustomRetry } = require('#internal/errors')
const { isError, kEmptyObject } = require('#internal/util')
const kDefaultIndent = '    ' // 4 spaces
const kFrameStartRegExp = /^ {4}at /
const kLineBreakRegExp = /\n|\r\n/
const kDefaultTAPVersion = 13
const inspectOptions = { colors: false, breakLength: Infinity }
let testModule // Lazy loaded due to circular dependency.

function lazyLoadTest () {
  testModule = testModule ?? require('#internal/test_runner/test')
  return testModule
}

async function * tapReporter (source) {
  yield `TAP version ${kDefaultTAPVersion}\n`
  for await (const { type, data } of source) {
    switch (type) {
      case 'test:fail':
        yield reportTest(data.nesting, data.testNumber, 'not ok', data.name, data.skip, data.todo)
        yield reportDetails(data.nesting, data.details)
        break
      case 'test:pass':
        yield reportTest(data.nesting, data.testNumber, 'ok', data.name, data.skip, data.todo)
        yield reportDetails(data.nesting, data.details)
        break
      case 'test:plan':
        yield `${indent(data.nesting)}1..${data.count}\n`
        break
      case 'test:start':
        yield `${indent(data.nesting)}# Subtest: ${tapEscape(data.name)}\n`
        break
      case 'test:diagnostic':
        yield `${indent(data.nesting)}# ${tapEscape(data.message)}\n`
        break
    }
  }
}

function reportTest (nesting, testNumber, status, name, skip, todo) {
  let line = `${indent(nesting)}${status} ${testNumber}`

  if (name) {
    line += ` ${tapEscape(`- ${name}`)}`
  }

  if (skip !== undefined) {
    line += ` # SKIP${typeof skip === 'string' && skip.length ? ` ${tapEscape(skip)}` : ''}`
  } else if (todo !== undefined) {
    line += ` # TODO${typeof todo === 'string' && todo.length ? ` ${tapEscape(todo)}` : ''}`
  }

  line += '\n'

  return line
}

function reportDetails (nesting, data = kEmptyObject) {
  const { error, duration_ms } = data // eslint-disable-line camelcase
  const _indent = indent(nesting)
  let details = `${_indent}  ---\n`

  details += jsToYaml(_indent, 'duration_ms', duration_ms)
  details += jsToYaml(_indent, null, error)
  details += `${_indent}  ...\n`
  return details
}

const memo = new SafeMap()
function indent (nesting) {
  let value = memo.get(nesting)
  if (value === undefined) {
    value = StringPrototypeRepeat(kDefaultIndent, nesting)
    memo.set(nesting, value)
  }

  return value
}

// In certain places, # and \ need to be escaped as \# and \\.
function tapEscape (input) {
  let result = StringPrototypeReplaceAll(input, '\b', '\\b')
  result = StringPrototypeReplaceAll(result, '\f', '\\f')
  result = StringPrototypeReplaceAll(result, '\t', '\\t')
  result = StringPrototypeReplaceAll(result, '\n', '\\n')
  result = StringPrototypeReplaceAll(result, '\r', '\\r')
  result = StringPrototypeReplaceAll(result, '\v', '\\v')
  result = StringPrototypeReplaceAll(result, '\\', '\\\\')
  result = StringPrototypeReplaceAll(result, '#', '\\#')
  return result
}

function jsToYaml (indent, name, value) {
  if (value === null || value === undefined) {
    return ''
  }

  if (typeof value !== 'object') {
    const prefix = `${indent}  ${name}: `

    if (typeof value !== 'string') {
      return `${prefix}${inspectWithNoCustomRetry(value, inspectOptions)}\n`
    }

    const lines = StringPrototypeSplit(value, kLineBreakRegExp)

    if (lines.length === 1) {
      return `${prefix}${inspectWithNoCustomRetry(value, inspectOptions)}\n`
    }

    let str = `${prefix}|-\n`

    for (let i = 0; i < lines.length; i++) {
      str += `${indent}    ${lines[i]}\n`
    }

    return str
  }

  const entries = ObjectEntries(value)
  const isErrorObj = isError(value)
  let result = ''

  for (let i = 0; i < entries.length; i++) {
    const { 0: key, 1: value } = entries[i]

    if (isErrorObj && (key === 'cause' || key === 'code')) {
      continue
    }

    result += jsToYaml(indent, key, value)
  }

  if (isErrorObj) {
    const { kTestCodeFailure, kUnwrapErrors } = lazyLoadTest()
    const {
      cause,
      code,
      failureType,
      message,
      expected,
      actual,
      operator,
      stack
    } = value
    let errMsg = message ?? '<unknown error>'
    let errStack = stack
    let errCode = code
    let errExpected = expected
    let errActual = actual
    let errOperator = operator
    let errIsAssertion = isAssertionLike(value)

    // If the ERR_TEST_FAILURE came from an error provided by user code,
    // then try to unwrap the original error message and stack.
    if (code === 'ERR_TEST_FAILURE' && kUnwrapErrors.has(failureType)) {
      errStack = cause?.stack ?? errStack
      errCode = cause?.code ?? errCode
      if (isAssertionLike(cause)) {
        errExpected = cause.expected
        errActual = cause.actual
        errOperator = cause.operator ?? errOperator
        errIsAssertion = true
      }
      if (failureType === kTestCodeFailure) {
        errMsg = cause?.message ?? errMsg
      }
    }

    result += jsToYaml(indent, 'error', errMsg)

    if (errCode) {
      result += jsToYaml(indent, 'code', errCode)
    }

    if (errIsAssertion) {
      result += jsToYaml(indent, 'expected', errExpected)
      result += jsToYaml(indent, 'actual', errActual)
      if (errOperator) {
        result += jsToYaml(indent, 'operator', errOperator)
      }
    }

    if (typeof errStack === 'string') {
      const frames = []

      ArrayPrototypeForEach(
        StringPrototypeSplit(errStack, kLineBreakRegExp),
        (frame) => {
          const processed = RegExpPrototypeSymbolReplace(
            kFrameStartRegExp,
            frame,
            ''
          )

          if (processed.length > 0 && processed.length !== frame.length) {
            ArrayPrototypePush(frames, processed)
          }
        }
      )

      if (frames.length > 0) {
        const frameDelimiter = `\n${indent}    `

        result += `${indent}  stack: |-${frameDelimiter}`
        result += `${ArrayPrototypeJoin(frames, frameDelimiter)}\n`
      }
    }
  }

  return result
}

function isAssertionLike (value) {
  return value && typeof value === 'object' && 'expected' in value && 'actual' in value
}

module.exports = tapReporter