dangerfile.js

// @flow

import { danger, warn, fail, message } from 'danger'
import semver from 'semver'
import fs from 'fs'
import jest from 'danger-plugin-jest'

jest()

const jsModifiedFiles = danger.git.modified_files.filter(
  path => path.startsWith('src') && path.endsWith('js')
)
const vendorModifiedFiles = danger.git.modified_files.filter(
  path => path.startsWith('src/vendor') && path.endsWith('js')
)

const hasAppChanges =
  jsModifiedFiles.filter(filepath => !filepath.endsWith('test.js')).length > 0
const jsTestChanges = jsModifiedFiles.filter(filepath =>
  filepath.endsWith('test.js')
)
const hasTestChanges = jsTestChanges.length > 0

// Congrats, version bump up!
danger.git.diffForFile('package.json').then(packageDiff => {
  if (
    packageDiff &&
    packageDiff.version &&
    packageDiff.version.before &&
    packageDiff.version.after
  ) {
    if (semver.lt(packageDiff.version.before, packageDiff.version.after)) {
      message(':tada: Version BUMP UP!')
    }
  }
})

// Fail if there are app changes without a CHANGELOG
if (!danger.git.modified_files.includes('CHANGELOG.md') && hasAppChanges) {
  const changelogLink =
    'https://github.com/styled-components/styled-components/blob/master/CHANGELOG.md'
  fail(
    `Please include a CHANGELOG entry. You can find it at <a href='${changelogLink}'>CHANGELOG.md</a>`
  )
}

// Warn if there are library changes, but not tests (excluding vendor)
const libraryOnlyFiles = jsModifiedFiles.filter(
  file => !vendorModifiedFiles.includes(file)
)
if (libraryOnlyFiles.length > 0 && !hasTestChanges) {
  warn(
    "There are library changes, but not tests. That's OK as long as you're refactoring existing code"
  )
}

// Warn if StyledComponent.js was edited but not StyledNativeComponent.js or viceversa
const hasStyledChanges =
  danger.git.modified_files.find(path =>
    path.endsWith('StyledComponent.js')
  ) !== null
const hasNativeStyledChanges =
  danger.git.modified_files.find(path =>
    path.endsWith('StyledNativeComponent.js')
  ) !== null
if (hasStyledChanges && !hasNativeStyledChanges) {
  warn(
    "A change was made in StyledComponent.js that wasn't made in StyledNativeComponent.js or viceversa."
  )
}

// Changes to these files may need SemVer bumps
const semverBumpFiles = [
  'ThemeProvider.js',
  'StyledComponent.js',
  'StyledNativeComponent.js',
]
semverBumpFiles.forEach(file => {
  if (jsModifiedFiles.includes(file)) {
    warn('Changes to #{file} might be SemVer major changes.')
  }
})

// Be careful of leaving testing shortcuts in the codebase
jsTestChanges.forEach(file => {
  const content = fs.readFileSync(file).toString()
  if (content.includes('it.only') || content.includes('describe.only')) {
    fail(`an \`only\` was left in tests (${file})`)
  }
})