@zoroaster/fork

@zoroaster/fork

@zoroaster/fork is used in Zoroaster to test forks.

yarn add -E @zoroaster/fork

Table Of Contents

• Table Of Contents
• API
• async fork(forkConfig: string|ForkConfig, input: string, props?: *, contexts?: Context[]): { stdout, stderr, code }
  • ForkConfig
• Copyright

API

The package is available by importing its default function:

import fork from '@zoroaster/fork'

async fork(
  forkConfig: string|ForkConfig,
  input: string,
  props?: *,
  contexts?: Context[],
): { stdout, stderr, code }

This method will fork a process, and pass the inputs when stdin expects an input. Because includeAnswers is set to true by default, the answers will be included in the resulting stdout and stderr properties.

import('child_process').ForkOptions child_process.ForkOptions

ForkConfig: Parameters for forking.

Name	Type	Description	Default
module*	string	The path to the module to fork.	-
getArgs	(args: string[], ...contexts?: Context[]) => string[]|Promise<string[]>	The function to get arguments to pass the fork based on the parsed mask input and contexts.	-
getOptions	(...contexts?: Context[]) => ForkOptions	The function to get options for the fork, such as ENV and cwd, based on contexts.	-
options	ForkOptions	Options for the forked processed, such as ENV and cwd.	-
inputs	[RegExp, string][]	Inputs to push to stdin when stdout writes data. The inputs are kept on stack, and taken off the stack when the RegExp matches the written data.	-
stderrInputs	[RegExp, string][]	Inputs to push to stdin when stderr writes data (similar to inputs).	-
log	boolean | {stderr: Writable, stdout: Writable}	Whether to pipe data from stdout, stderr to the process's streams. If an object is passed, the output will be piped to streams specified as its stdout and stderr properties.	false
includeAnswers	boolean	Whether to add the answers to the stderr and stdout output.	true
stripAnsi	boolean	Remove ANSI escape sequences from the stdout and stderr prior to checking of the result.	true
preprocess	(function | {stdout?:function, stderr?:function})	The function to run on stdout and stderr before comparing it to the output. Pass an object with stdout and stderr properties for individual pre-processors.	-

For example, to test the fork with the next code:

const [,, ...args] = process.argv
console.log(args)
console.error(process.env.EXAMPLE)
process.exit(5)

The ContextTesting/Fork can be used:

/* yarn example/ */
import fork from '@zoroaster/fork'

(async () => {
  const res = await fork({
    contexts: ['CONTEXT'],
    forkConfig: {
      module: 'example/fork',
      getArgs(inputs) {
        return [...inputs, this.prop1]
      },
      getOptions(CONTEXT) {
        return {
          env: {
            EXAMPLE: `${CONTEXT} - ${this.input}`,
          },
        }
      },
      preprocess(s) {
        /* e.g., to remove whitespace at the end of each line
          s.split('\n').map(a => a.trimRight()).join('\n')
        */
        return `pre-${s}`
      },
      /* stripAnsi: true */
    },
    input: 'hello world',
    props: {
      prop1: '999',
      stdout: `pre-[ 'hello', 'world', '999' ]`,
      stderr: 'pre-CONTEXT - hello world',
    },
  })
  console.log(res)
})()

{ code: 5,
  stdout: '[ \'hello\', \'world\', \'999\' ]\n',
  stderr: 'CONTEXT - hello world\n' }

Copyright

(c) Context Testing 2019