execa-wrap

Wraps execa and makes output suitable for snapshot testing

Install

Requires Node version 6 or above.

npm install --save execa-wrap

Use

From the tests, include both this module and snap-shot-it

const execaWrap = require('execa-wrap')
const snapshot = require('snap-shot-it')
describe('execa-wrap', () => {
  it('ls', () => {
    return execaWrap('ls', ['src']).then(snapshot)
  })
})

$ cat __snapshots__/execa-wrap-spec.js
exports['execa-wrap ls 1'] = `
  command: ls src
  code: 0
  failed: false
  killed: false
  signal: null
  timedOut: false
 
  stdout:
  -------
  execa-wrap-spec.js
  index.js
  -------
  stderr:
  -------
 
  -------
  `

You probably want to cleanup the output before the snapshot step. For example, you might want to remove timings, stack traces, etc.

If the program fails, the output and everything else will be processed the same way. Thus you can test the programs returning non-zero exit codes by just attaching resolved promise callback

const execaWrap = require('execa-wrap')
execaWrap('failing-command', ['its', 'arguments'])
  .then(output => {
    // output will be text like above but with
    // details like exit code and stderr
  })

You can pass other options to execa, for example environment variables

const execaWrap = require('execa-wrap')
execaWrap('failing-command', ['its', 'arguments'], {
  env: {
    FOO: 'foo'
  }
})

Filtering properties

If you are not interested in every returned property, you can filter and get only some properties. For example, let us grab command and stdout

execaWrap('ls', ['src'], {filter: ['cmd', 'stdout']})
// command: ls src
// stdout
// ------

For a single filter, just use a string or single item array

execaWrap('ls', ['src'], {filter: 'cmd'})
// command: ls src

Debug

To see internal log messages, run with DEBUG=execa-wrap environment variable

Small print

Author: Gleb Bahmutov <gleb.bahmutov@gmail.com> © 2017

• @bahmutov
• glebbahmutov.com
• blog

License: MIT - do anything with the code, but don't blame me if it does not work.

Support: if you find any problems with this module, email / tweet / open issue on Github

MIT License

Copyright (c) 2017 Gleb Bahmutov <gleb.bahmutov@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.