@japa/errors-printer

Error printer to pretty print Japa errors

Installation

Install the package from the npm registry as follows:

npm i @japa/errors-printer

yarn add @japa/errors-printer

pnpm add @japa/errors-printer

Usage

You can print errors produced by japa test runner as follows.

import { ErrorsPrinter } from '@japa/errors-printer'

const printer = new ErrorsPrinter()
const error = new Error('boom')

await printer.printError(error)

Most of the times, you will find yourself printing errors using the Japa test summary. Here is how you can go about doing it.

import { ErrorsPrinter } from '@japa/errors-printer'

const printer = new ErrorsPrinter()

// assuming you have the runner instance
const summary = runner.getSummary()
const errorsList = []

summary.failureTree.forEach((suite) => {
  suite.errors.forEach((error) => {
    errorsList.push({ title: suite.name, ...error })
  })

  suite.children.forEach((groupOrTest) => {
    if (groupOrTest.type === 'test') {
      groupOrTest.errors.forEach((error) => {
        errorsList.push({ title: groupOrTest.title, ...error })
      })
      return
    }

    groupOrTest.errors.forEach((error) => {
      errorsList.push({ title: groupOrTest.name, ...error })
    })
    groupOrTest.children.forEach((test) => {
      test.errors.forEach((error) => {
        errorsList.push({ title: test.title, ...error })
      })
    })
  })
})

await printer.printErrors(errorsList)

API

Following are the available methods.

printError()

Accepts error as the only argument. If the error is an assertion error, then the diff will be displayed. Otherwise, the error stack is printed.

Assertion diff

import { Assert } from '@japa/assert'
import { ErrorsPrinter } from '@japa/errors-printer'

const printer = new ErrorsPrinter()

try {
  new Assert().deepEqual({ id: 1 }, { id: 2 })
} catch (error) {
  await printer.printError(error)
}

Jest error

import expect from 'expect'
import { ErrorsPrinter } from '@japa/errors-printer'

const printer = new ErrorsPrinter()

try {
  expect({ bar: 'baz' }).toEqual(expect.not.objectContaining({ bar: 'baz' }))
} catch (error) {
  await printer.printError(error)
}

Error stack

import { ErrorsPrinter } from '@japa/errors-printer'

const printer = new ErrorsPrinter()
await printer.printError(new Error('boom'))

printErrors

Print an array of errors produced by the Japa test runner summary. The method accepts an array of errors in the following format.

type Error = {
  title: string,
  phase: string,
  error: Error
}

await printer.printErrors([
  {
    phase: 'test',
    title: '2 + 2 = 4'
    error: new Error('test failed')
  },
  {
    phase: 'teardown',
    title: '2 + 2 = 4'
    error: new Error('teardown failed')
  }
])