Ensure "clean" target matches --destination flag

gulpfile.js

@@ -1,7 +1,7 @@
 const gulp = require('gulp')
 const taskListing = require('gulp-task-listing')
 const configPaths = require('./config/paths.js')
-const taskArguments = require('./tasks/task-arguments')
+const { destination } = require('./tasks/task-arguments.js')
 
 // Gulp sub-tasks
 require('./tasks/gulp/compile-assets.js')
@@ -12,7 +12,7 @@ require('./tasks/gulp/watch.js')
 const { buildSassdocs } = require('./tasks/sassdoc.js')
 const { runNodemon } = require('./tasks/nodemon.js')
 const { updateDistAssetsVersion } = require('./tasks/asset-version.js')
-const { cleanDist, cleanPackage, cleanPublic } = require('./tasks/clean.js')
+const { clean } = require('./tasks/clean.js')
 const { npmScriptTask } = require('./tasks/run.js')
 
 /**
@@ -38,8 +38,8 @@ gulp.task('styles', gulp.series(
  * Copies assets to taskArguments.destination (public)
  */
 gulp.task('copy:assets', () => {
-  return gulp.src(configPaths.src + 'assets/**/*')
-    .pipe(gulp.dest(taskArguments.destination + '/assets/'))
+  return gulp.src(`${configPaths.src}assets/**/*`)
+    .pipe(gulp.dest(`${destination}/assets/`))
 })
 
 /**
@@ -67,7 +67,7 @@ gulp.task('serve', gulp.parallel(
  * Runs a sequence of tasks on start
  */
 gulp.task('dev', gulp.series(
-  cleanPublic,
+  clean,
   'compile',
   'serve'
 ))
@@ -77,7 +77,7 @@ gulp.task('dev', gulp.series(
  * Prepare package folder for publishing
  */
 gulp.task('build:package', gulp.series(
-  cleanPackage,
+  clean,
   'copy:files',
   'js:compile'
 ))
@@ -87,7 +87,7 @@ gulp.task('build:package', gulp.series(
  * Prepare dist folder for release
  */
 gulp.task('build:dist', gulp.series(
-  cleanDist,
+  clean,
   'compile',
   'copy:assets',
   updateDistAssetsVersion

package.json

@@ -85,6 +85,7 @@
     "sass-color-helpers": "^2.1.1",
     "sassdoc": "^2.7.4",
     "shuffle-seed": "^1.1.6",
+    "slash": "^3.0.0",
     "standard": "^17.0.0",
     "stylelint": "^14.13.0",
     "stylelint-config-gds": "^0.2.0",

tasks/asset-version.js

@@ -1,19 +1,23 @@
-const configPaths = require('../config/paths.js')
 const { rename, writeFile } = require('fs/promises')
 const { basename, resolve } = require('path')
 
+const configPaths = require('../config/paths.js')
+const { destination, isDist } = require('./task-arguments.js')
+
 // Update assets' version numbers
 // Uses the version number from `package/package.json` and writes it to various places
 async function updateDistAssetsVersion () {
-  const distFolder = 'dist'
+  const pkg = require(`../${configPaths.package}package.json`)
 
-  const pkg = require('../' + configPaths.package + 'package.json')
+  if (!isDist) {
+    throw new Error('Asset versions can only be applied to ./dist')
+  }
 
   // Files to process
   const assetFiles = [
-    resolve(`${distFolder}/govuk-frontend.min.css`),
-    resolve(`${distFolder}/govuk-frontend-ie8.min.css`),
-    resolve(`${distFolder}/govuk-frontend.min.js`)
+    resolve(`${destination}/govuk-frontend.min.css`),
+    resolve(`${destination}/govuk-frontend-ie8.min.css`),
+    resolve(`${destination}/govuk-frontend.min.js`)
   ]
 
   // Loop through files
@@ -26,7 +30,7 @@ async function updateDistAssetsVersion () {
   })
 
   // Write VERSION.txt file
-  assetTasks.push(writeFile(resolve(`${distFolder}/VERSION.txt`), pkg.version + '\r\n'))
+  assetTasks.push(writeFile(resolve(`${destination}/VERSION.txt`), pkg.version + '\r\n'))
 
   // Resolve on completion
   return Promise.all(assetTasks)

tasks/clean.js

@@ -1,34 +1,30 @@
 const del = require('del')
-const configPaths = require('../config/paths.js')
 
-function cleanDist () {
-  return del([
-    `${configPaths.dist}**/*`
-  ])
-}
+const { destination } = require('./task-arguments.js')
+
+function paths () {
+  const param = [`${destination}/**/*`]
+
+  // Preserve package files
+  if (destination === 'package') {
+    param.push(
+      `!${destination}/`,
+      `!${destination}/package.json`,
+      `!${destination}/govuk-prototype-kit.config.json`,
+      `!${destination}/README.md`
+    )
+  }
 
-function cleanPackage () {
-  return del([
-    `${configPaths.package}**`,
-    `!${configPaths.package}`,
-    `!${configPaths.package}package.json`,
-    `!${configPaths.package}govuk-prototype-kit.config.json`,
-    `!${configPaths.package}README.md`
-  ])
+  return param
 }
 
-function cleanPublic () {
-  return del([
-    `${configPaths.public}**/*`
-  ])
+function clean () {
+  return del(paths())
 }
 
-cleanDist.displayName = 'clean:dist'
-cleanPackage.displayName = 'clean:package'
-cleanPublic.displayName = 'clean:public'
+clean.displayName = `clean:${destination}`
 
 module.exports = {
-  cleanDist,
-  cleanPackage,
-  cleanPublic
+  paths,
+  clean
 }

tasks/clean.unit.test.js

@@ -0,0 +1,36 @@
+describe('Clean task', () => {
+  beforeEach(() => {
+    jest.resetModules()
+  })
+
+  it.each(
+    [
+      {
+        destination: 'public',
+        paths: ['public/**/*']
+      },
+      {
+        destination: 'package',
+        paths: [
+          'package/**/*',
+          '!package/',
+          '!package/package.json',
+          '!package/govuk-prototype-kit.config.json',
+          '!package/README.md'
+        ]
+      },
+      {
+        destination: 'dist',
+        paths: ['dist/**/*']
+      },
+      {
+        destination: 'custom/location/here',
+        paths: ['custom/location/here/**/*']
+      }
+    ]
+  )('cleans destination "$destination"', async ({ destination, paths }) => {
+    jest.mock('./task-arguments.js', () => ({ destination }))
+    const clean = await import('./clean.js')
+    expect(clean.paths()).toEqual(paths)
+  })
+})

tasks/gulp/compile-assets.js

@@ -3,13 +3,11 @@ const { componentNameToJavaScriptModuleName } = require('../../lib/helper-functi
 const path = require('path')
 
 const gulp = require('gulp')
-const configPaths = require('../../config/paths.js')
 const sass = require('gulp-sass')(require('node-sass'))
 const plumber = require('gulp-plumber')
 const postcss = require('gulp-postcss')
 const autoprefixer = require('autoprefixer')
 const rollup = require('gulp-better-rollup')
-const taskArguments = require('../task-arguments')
 const gulpif = require('gulp-if')
 const uglify = require('gulp-uglify')
 const eol = require('gulp-eol')
@@ -23,22 +21,19 @@ const postcsspseudoclasses = require('postcss-pseudo-classes')({
   blacklist: [':not(', ':disabled)', ':first-child)', ':last-child)', ':focus)', ':active)', ':hover)']
 })
 
+const configPaths = require('../../config/paths.js')
+const { destination, isDist, isPublic } = require('../task-arguments.js')
+
 // Compile CSS and JS task --------------
 // --------------------------------------
 
-// check if destination flag is public (this is the default)
-const isPublic = taskArguments.destination === 'public' || false
-
-// check if destination flag is dist
-const isDist = taskArguments.destination === 'dist' || false
-
 // Set the destination
 const destinationPath = function () {
-  // Public & Dist directories do no need namespaced with `govuk`
-  if (taskArguments.destination === 'dist' || taskArguments.destination === 'public') {
-    return taskArguments.destination
+  // Public & Dist directories not namespaced with `govuk`
+  if (isDist || isPublic) {
+    return destination
   } else {
-    return `${taskArguments.destination}/govuk/`
+    return `${destination}/govuk/`
   }
 }
 
@@ -74,7 +69,7 @@ function compileStyles () {
         extname: '.min.css'
       })
     ))
-    .pipe(gulp.dest(taskArguments.destination + '/'))
+    .pipe(gulp.dest(`${destination}/`))
 }
 
 function compileOldIE () {
@@ -111,7 +106,7 @@ function compileOldIE () {
         extname: '.min.css'
       })
     ))
-    .pipe(gulp.dest(taskArguments.destination + '/'))
+    .pipe(gulp.dest(`${destination}/`))
 }
 
 function compileLegacy () {
@@ -126,7 +121,7 @@ function compileLegacy () {
       // :hover class you can use to simulate the hover state in the review app
       postcsspseudoclasses
     ]))
-    .pipe(gulp.dest(taskArguments.destination + '/'))
+    .pipe(gulp.dest(`${destination}/`))
 }
 
 function compileLegacyIE () {
@@ -145,7 +140,7 @@ function compileLegacyIE () {
         pseudo: { disable: true }
       })
     ]))
-    .pipe(gulp.dest(taskArguments.destination + '/'))
+    .pipe(gulp.dest(`${destination}/`))
 }
 
 function compileFullPageStyles () {
@@ -158,7 +153,7 @@ function compileFullPageStyles () {
       location.basename = location.dirname
       location.dirname = ''
     }))
-    .pipe(gulp.dest(taskArguments.destination + '/full-page-examples/'))
+    .pipe(gulp.dest(`${destination}/full-page-examples/`))
 }
 
 gulp.task('scss:compile', function (done) {

tasks/gulp/copy-to-destination.js

@@ -11,7 +11,7 @@ const merge = require('merge-stream')
 const rename = require('gulp-rename')
 
 const configPaths = require('../../config/paths.js')
-const taskArguments = require('../task-arguments')
+const { destination } = require('../task-arguments.js')
 
 gulp.task('copy:files', () => {
   return merge(
@@ -22,7 +22,7 @@ gulp.task('copy:files', () => {
     gulp.src([
       `${configPaths.src}**/*.mjs`,
       `!${configPaths.src}**/*.test.*`
-    ]).pipe(gulp.dest(`${taskArguments.destination}/govuk-esm/`)),
+    ]).pipe(gulp.dest(`${destination}/govuk-esm/`)),
 
     /**
      * Copy files to destination with './govuk' suffix
@@ -77,7 +77,7 @@ gulp.task('copy:files', () => {
           basename: 'macro-options',
           extname: '.json'
         }))
-    ).pipe(gulp.dest(`${taskArguments.destination}/govuk/`))
+    ).pipe(gulp.dest(`${destination}/govuk/`))
   )
 })
 

tasks/task-arguments.js

@@ -1,4 +1,38 @@
-const argv = require('yargs').argv
-const destination = argv.destination ? argv.destination : 'public'
+const { dirname, relative, resolve } = require('path')
 
-exports.destination = destination
+const slash = require('slash')
+const { argv } = require('yargs')
+
+// Defaults for known tasks
+const destinations = [
+  {
+    task: 'build:package',
+    destination: 'package'
+  },
+  {
+    task: 'build:dist',
+    destination: 'dist'
+  }
+]
+
+// Non-flag arguments
+const { _: tasks } = argv
+
+// Prefer `--destination`, default for known task, or 'public'
+const destination = argv.destination || (destinations
+  .filter(({ task }) => tasks.includes(task))[0]?.destination ?? 'public')
+
+const rootPath = dirname(__dirname)
+const destPath = resolve(rootPath, destination)
+
+module.exports = {
+  argv,
+
+  // Normalise slashes (Windows) for gulp.src
+  destination: slash(relative(rootPath, destPath)),
+
+  // Check destination flags
+  isPackage: destination === 'package',
+  isPublic: destination === 'public',
+  isDist: destination === 'dist'
+}