watch.js

'use strict'
const test = require('ava')

const fs = require('fs-extra')
const path = require('path')
const { exec, spawn } = require('child_process')
const chokidar = require('chokidar')

const ENV = require('./helpers/env.js')
const read = require('./helpers/read.js')
const tmp = require('./helpers/tmp.js')

// XXX: All the tests in this file are skipped on the CI; too flacky there
const testCb = process.env.CI ? test.cb.skip : test.cb

testCb('--watch works', (t) => {
  let cp

  t.plan(2)

  ENV('', ['a.css'])
    .then((dir) => {
      // Init watcher:
      const watcher = chokidar.watch('.', {
        cwd: dir,
        ignoreInitial: true,
        awaitWriteFinish: true,
      })

      // On the first output:
      watcher.on('add', (p) => {
        // Assert, then change the source file
        if (p === 'output.css') {
          isEqual(p, 'test/fixtures/a.css')
            .then(() => read('test/fixtures/b.css'))
            .then((css) => fs.writeFile(path.join(dir, 'a.css'), css))
            .catch(done)
        }
      })

      // When the change is picked up:
      watcher.on('change', (p) => {
        if (p === 'output.css') {
          isEqual(p, 'test/fixtures/b.css')
            .then(() => done())
            .catch(done)
        }
      })

      // Start postcss-cli:
      watcher.on('ready', () => {
        // Using exec() and quoting "*.css" to test watch's glob handling:
        cp = exec(
          `node ${path.resolve(
            'bin/postcss'
          )} "*.css" -o output.css --no-map -w`,
          { cwd: dir }
        )
        cp.on('error', t.end)
        cp.on('exit', (code) => {
          if (code) t.end(code)
        })
      })

      // Helper functions:
      function isEqual(p, expected) {
        return Promise.all([
          read(path.join(dir, p)),
          read(expected),
        ]).then(([a, e]) => t.is(a, e))
      }

      function done(err) {
        try {
          cp.kill()
        } catch {}

        t.end(err)
      }
    })
    .catch(t.end)

  // Timeout:
  setTimeout(() => t.end('test timeout'), 50000)
})

testCb('--watch postcss.config.js', (t) => {
  let cp

  t.plan(2)

  ENV('module.exports = {}', ['import.css', 'a.css'])
    .then((dir) => {
      // Init watcher:
      const watcher = chokidar.watch('.', {
        cwd: dir,
        ignoreInitial: true,
        awaitWriteFinish: true,
      })

      // On the first output:
      watcher.on('add', (p) => {
        // Assert, then change the source file
        if (p === 'output.css') {
          read(path.join(dir, p))
            .then((css) => {
              t.is(css, '@import "./a.css";\n')

              return fs.writeFile(
                path.join(dir, 'postcss.config.js'),
                `module.exports = {
                  plugins: [
                    require('postcss-import')()
                  ]
                }`
              )
            })
            .catch(done)
        }
      })

      // When the change is picked up:
      watcher.on('change', (p) => {
        if (p === 'output.css') {
          isEqual(p, 'test/fixtures/a.css')
            .then(() => done())
            .catch(done)
        }
      })

      // Start postcss-cli:
      watcher.on('ready', () => {
        cp = exec(
          `node ${path.resolve(
            'bin/postcss'
          )} import.css -o output.css -w --no-map`,
          { cwd: dir }
        )

        cp.on('error', t.end)
        cp.on('exit', (code) => {
          if (code) t.end(code)
        })
      })

      // Helper functions:
      function isEqual(p, expected) {
        return Promise.all([
          read(path.join(dir, p)),
          read(expected),
        ]).then(([a, e]) => t.is(a, e))
      }

      function done(err) {
        try {
          cp.kill()
        } catch {}

        t.end(err)
      }
    })
    .catch(t.end)

  // Timeout:
  setTimeout(() => t.end('test timeout'), 50000)
})

testCb('--watch dependencies', (t) => {
  let cp

  t.plan(2)

  ENV('', ['import.css', 'a.css'])
    .then((dir) => {
      // Init watcher:
      const watcher = chokidar.watch('.', {
        cwd: dir,
        ignoreInitial: true,
        awaitWriteFinish: true,
      })

      // On the first output:
      watcher.on('add', (p) => {
        // Assert, then change the source file
        if (p === 'output.css') {
          isEqual(p, 'test/fixtures/a.css')
            .then(() => read('test/fixtures/b.css'))
            .then((css) => fs.writeFile(path.join(dir, 'a.css'), css))
            .catch(done)
        }
      })

      // When the change is picked up:
      watcher.on('change', (p) => {
        if (p === 'output.css') {
          isEqual(p, 'test/fixtures/b.css')
            .then(() => done())
            .catch(done)
        }
      })

      // Start postcss-cli:
      watcher.on('ready', () => {
        cp = exec(
          `node ${path.resolve(
            'bin/postcss'
          )} import.css -o output.css -u postcss-import -w --no-map`,
          { cwd: dir }
        )

        cp.on('error', t.end)
        cp.on('exit', (code) => {
          if (code) t.end(code)
        })
      })

      // Helper functions:
      function isEqual(p, expected) {
        return Promise.all([
          read(path.join(dir, p)),
          read(expected),
        ]).then(([a, e]) => t.is(a, e))
      }

      function done(err) {
        try {
          cp.kill()
        } catch {}
        t.end(err)
      }
    })
    .catch(t.end)

  // Timeout:
  setTimeout(() => t.end('test timeout'), 50000)
})

testCb("--watch doesn't exit on CssSyntaxError", (t) => {
  t.plan(0)

  ENV('', ['a.css'])
    .then((dir) => {
      // Init watcher:
      const watcher = chokidar.watch('.', {
        cwd: dir,
        ignoreInitial: true,
        awaitWriteFinish: true,
      })
      watcher.on('add', (p) => {
        if (p === 'output.css') {
          // Change to invalid CSS
          fs.writeFile(path.join(dir, 'a.css'), '.a { color: red').catch(done)
        }
      })

      let killed = false
      const cp = exec(
        `node ${path.resolve('bin/postcss')} a.css -o output.css -w --no-map`,
        { cwd: dir }
      )
      cp.on('error', t.end)
      cp.stderr.on('data', (chunk) => {
        // When error message is printed, kill the process after a timeout
        if (~chunk.indexOf('Unclosed block')) {
          setTimeout(() => {
            killed = true
            cp.kill()
          }, 1000)
        }
      })
      cp.on('exit', (code) => {
        if (!killed) return t.end(`Should not exit (exited with code ${code})`)
        done()
      })

      function done(err) {
        try {
          cp.kill()
        } catch {}

        t.end(err)
      }
    })
    .catch(t.end)

  // Timeout:
  setTimeout(() => t.end('test timeout'), 50000)
})

testCb('--watch does exit on closing stdin (Ctrl-D/EOF)', (t) => {
  t.plan(1)

  const cp = spawn(
    `./bin/postcss test/fixtures/a.css -o ${tmp()} -w --no-map`,
    { shell: true }
  )

  cp.on('error', t.end)
  cp.on('exit', (code) => {
    t.is(code, 0)
    t.end()
  })
  cp.stdin.end()
})