@smpx/snap-shot-core/src/cypress-system.js

Save / load named snapshots, useful for tests

'use strict'

const la = require('lazy-ass')
const is = require('check-more-types')

// storage adapter for Cypress E2E testing tool

/* global cy, expect, fetch */
la(is.fn(fetch), 'missing fetch')
const filename = 'snap-shot.json'

let snapshots

function loadSnapshots () {
  return snapshots
}

function saveSnapshots (snapshots) {
  const text = JSON.stringify(snapshots, null, 2) + '\n'
  cy.writeFile(filename, text)
}

function init () {
  // for now disable
  return Promise.resolve()
  // // find out the source for all test -> this spec file
  // const sites = callsites()
  // la(sites.length, 'missing callsite')
  // const specFileUrl = sites[1].filename
  // la(is.webUrl(specFileUrl), 'missing spec url', specFileUrl)
  // console.log('loading spec from', specFileUrl)

  // // specFileUrl is something like
  // // http://localhost:49829/__cypress/tests?p=cypress/integration/spec.js-438
  // // we will need to get "true" filename which in this case should be
  // // cypress/integration/spec.js
  // const pIndex = specFileUrl.indexOf('?p=')
  // const dotJsIndex = specFileUrl.indexOf('.js-', pIndex)
  // const specFile = specFileUrl.substr(pIndex + 3, dotJsIndex - pIndex)
  // console.log('specFile is "%s"', specFile)

  // // ignore arguments for now
  // api.fromCurrentFolder = () => specFile

  // // cache the fetched source, otherwise every test fetches it
  // const shouldFetch = api.readFileSync === dummyReadFileSync
  // if (shouldFetch) {
  //   return fetch(specFileUrl).then(r => r.text())
  //     .then(source => {
  //       // ignores filename for now
  //       api.readFileSync = () => source
  //     })
  //     .then(() => {
  //       return fetch('/__cypress/tests?p=./' + filename)
  //         .then(r => r.text())
  //         .then(function loadedText (text) {
  //           if (text.includes('BUNDLE_ERROR')) {
  //             return Promise.reject(new Error('not found'))
  //           }
  //           cy.log('loaded snapshots', filename)
  //           // the JSON is wrapped in webpack wrapper ;)
  //           const req = eval(text) // eslint-disable-line no-eval
  //           snapshots = req('1')
  //         })
  //         .catch(err => {
  //           console.error(err)
  //           snapshots = {}
  //         })
  //     })
  // } else {
  //   return Promise.resolve()
  // }
}

function raiseIfDifferent ({ value, expected }) {
  cy.then(() => {
    expect(value).to.equal(expected)
  })
}

function dummyReadFileSync () {
  throw new Error(`In the browser, please call snapshot.init()
    before calling tests, like this:
    const snapshot = require('snap-shot')
    beforeEach(snapshot.init)
  `)
}

// TODO replace exposed API with error methods that wait id:2
// Gleb Bahmutov
// gleb.bahmutov@gmail.com
// https://github.com/bahmutov/snap-shot-core/issues/87
// until "init" is called
const api = {
  loadSnapshots,
  saveSnapshots,
  init,
  readFileSync: dummyReadFileSync,
  raiseIfDifferent
}
module.exports = api