reorganize Gulp build

- rename exec argument to call
- pick off and use first argument of exportTasks function as default task
- remove use of path
- use gulp.watch instead of chokidar (which, in turn, uses chokidar)
- add loop and opts arguments to task function (currently unused)

6 files changed, 48 insertions, 45 deletions

diff --git a/gulpfile.js/index.js b/gulpfile.js/index.js
index 71ca933..2adc946 100644
--- a/gulpfile.js/index.js
+++ b/gulpfile.js/index.js
@@ -1,108 +1,102 @@
 'use strict'
 
 const { parallel, series, tree } = require('gulp')
-const camelcase = (name) => name.replace(/[-]./g, (m) => m.substr(1).toUpperCase())
-const exportTasks = require('./lib/export-tasks')
+const camelCase = (name) => name.replace(/[-]./g, (m) => m.substr(1).toUpperCase())
 const task = require('./lib/task')
-const taskFns = require('require-directory')(module, '.', { recurse: false, rename: camelcase })
-const path = require('path')
+const tasks = require('require-directory')(module, '.', { recurse: false, rename: camelCase })
 
 const bundleName = 'ui'
 const buildDir = 'build'
 const previewSiteSrcDir = 'preview-site-src'
 const previewSiteDestDir = 'public'
 const srcDir = 'src'
-const destDir = path.join(previewSiteDestDir, '_')
+const destDir = `${previewSiteDestDir}/_`
 const { reload: livereload } = process.env.LIVERELOAD === 'true' ? require('gulp-connect') : {}
 
-const cssFileGlobs = path.join(srcDir, 'css/**/*.css')
-const jsFileGlobs = ['gulpfile.js/**/*.js', path.join(srcDir, '{helpers,js}/**/*.js')]
-
-const { remove, lintCss, lintJs, format, build, pack, previewPages, previewServe } = taskFns
+const glob = { cssFiles: `${srcDir}/css/**/*.css`, jsFiles: ['gulpfile.js/**/*.js', `${srcDir}/{helpers,js}/**/*.js`] }
+const { remove, lintCss, lintJs, format, build, pack, previewPages, previewServe } = tasks
 
 const cleanTask = task({
   name: 'clean',
   desc: 'Clean files and folders generated by build',
-  exec: remove(['build', 'public']),
+  call: remove(['build', 'public']),
 })
 
 const lintCssTask = task({
   name: 'lint:css',
   desc: 'Lint the CSS source files using stylelint (standard config)',
-  exec: lintCss(cssFileGlobs),
+  call: lintCss(glob.cssFiles),
 })
 
 const lintJsTask = task({
   name: 'lint:js',
   desc: 'Lint the JavaScript source files using eslint (JavaScript Standard Style)',
-  exec: lintJs(jsFileGlobs),
+  call: lintJs(glob.jsFiles),
 })
 
 const lintTask = task({
   name: 'lint',
   desc: 'Lint the CSS and JavaScript source files',
-  exec: parallel(lintCssTask, lintJsTask),
+  call: parallel(lintCssTask, lintJsTask),
 })
 
 const formatTask = task({
   name: 'format',
   desc: 'Format the JavaScript source files using prettify (JavaScript Standard Style)',
-  exec: format(jsFileGlobs),
+  call: format(glob.jsFiles),
 })
 
 const buildTask = task({
   name: 'build',
   desc: 'Build and stage the UI assets for bundling',
-  exec: build(srcDir, destDir, tree().nodes.some((name) => ~name.indexOf('preview'))),
+  call: build(srcDir, destDir, tree().nodes.some((name) => ~name.indexOf('preview'))),
 })
 
 const bundleBuildTask = task({
   name: 'bundle:build',
-  exec: series(cleanTask, lintTask, buildTask),
+  call: series(cleanTask, lintTask, buildTask),
 })
 
 const bundlePackTask = task({
   name: 'bundle:pack',
   desc: 'Create a bundle of the staged UI assets for publishing',
-  exec: pack(destDir, buildDir, bundleName),
+  call: pack(destDir, buildDir, bundleName),
 })
 
 const bundleTask = task({
   name: 'bundle',
   desc: 'Clean, lint, build, and bundle the UI for publishing',
-  exec: series(bundleBuildTask, bundlePackTask),
+  call: series(bundleBuildTask, bundlePackTask),
 })
 
 const previewPagesTask = task({
   name: 'preview:pages',
-  exec: previewPages(srcDir, destDir, previewSiteSrcDir, previewSiteDestDir, livereload),
+  call: previewPages(srcDir, destDir, previewSiteSrcDir, previewSiteDestDir, livereload),
 })
 
 const previewBuildTask = task({
   name: 'preview:build',
   desc: 'Process and stage the UI assets and generate pages for the preview',
-  exec: parallel(buildTask, previewPagesTask),
+  call: parallel(buildTask, previewPagesTask),
 })
 
 const previewServeTask = task({
   name: 'preview:serve',
-  exec: previewServe(previewSiteDestDir, {
+  call: previewServe(previewSiteDestDir, {
     port: 5252,
     livereload,
-    watch: { src: [srcDir, previewSiteSrcDir], onChange: previewBuildTask },
+    watch: { glob: [srcDir, previewSiteSrcDir], call: previewBuildTask },
   }),
 })
 
 const previewTask = task({
   name: 'preview',
   desc: 'Generate a preview site and launch a server to view it',
-  exec: series(previewBuildTask, previewServeTask),
+  call: series(previewBuildTask, previewServeTask),
 })
 
-const defaultTask = task({ name: 'default', desc: `(${bundleTask.displayName})`, exec: series(bundleTask) })
-
-module.exports = exportTasks(
-  defaultTask,
+module.exports = require('./lib/export-tasks')(
+  bundleTask,
   cleanTask,
   lintTask,
   formatTask,
diff --git a/gulpfile.js/lib/export-tasks.js b/gulpfile.js/lib/export-tasks.js
index 834cd9e..7c9de48 100644
--- a/gulpfile.js/lib/export-tasks.js
+++ b/gulpfile.js/lib/export-tasks.js
@@ -1,4 +1,14 @@
 'use strict'
 
-module.exports = (...tasks) =>
-  tasks.reduce((acc, task) => (acc[task.displayName || task.name] = task) && acc, { default: tasks.shift() })
+module.exports = (...tasks) => {
+  const seed = {}
+  if (tasks.length) {
+    if (tasks.lastIndexOf(tasks[0]) > 0) {
+      const task1 = tasks.shift()
+      seed.default = Object.assign(task1.bind(null), { description: `=> ${task1.displayName}`, displayName: 'default' })
+    }
+    return tasks.reduce((acc, it) => (acc[it.displayName || it.name] = it) && acc, seed)
+  } else {
+    return seed
+  }
+}
diff --git a/gulpfile.js/lib/task.js b/gulpfile.js/lib/task.js
index 9878f27..8c90062 100644
--- a/gulpfile.js/lib/task.js
+++ b/gulpfile.js/lib/task.js
@@ -1,8 +1,9 @@
 'use strict'
 
 const metadata = require('undertaker/lib/helpers/metadata')
+const { watch } = require('gulp')
 
-module.exports = ({ name, desc, exec: fn }) => {
+module.exports = ({ name, desc, opts, call: fn, loop }) => {
   if (name) {
     const displayName = fn.displayName
     if (displayName === '<series>' || displayName === '<parallel>') {
@@ -10,6 +11,14 @@ module.exports = ({ name, desc, exec: fn }) => {
     }
     fn.displayName = name
   }
+  if (loop) {
+    const delegate = fn
+    name = delegate.displayName
+    delegate.displayName = `${name}:loop`
+    fn = () => watch(loop, { ignoreInitial: false }, delegate)
+    fn.displayName = name
+  }
   if (desc) fn.description = desc
+  if (opts) fn.flags = opts
   return fn
 }
diff --git a/gulpfile.js/preview-serve.js b/gulpfile.js/preview-serve.js
index 9dcf39e..8ae70cf 100644
--- a/gulpfile.js/preview-serve.js
+++ b/gulpfile.js/preview-serve.js
@@ -1,23 +1,14 @@
 'use strict'
 
-const chokidar = require('chokidar')
 const connect = require('gulp-connect')
+const { watch } = require('gulp')
 
 module.exports = (serveDir, opts = {}) => (done) => {
-  const watch = opts.watch
+  const { glob: watchGlob, call: watchCall } = opts.watch || {}
+  opts = { ...opts, root: serveDir }
   delete opts.watch
-  opts = Object.assign({ root: serveDir }, opts)
-  let onStart
-  if (watch && watch.src && watch.onChange) {
-    onStart = () =>
-      chokidar
-        .watch(watch.src, { ignoreInitial: true })
-        .on('add', watch.onChange)
-        .on('change', watch.onChange)
-        .on('unlink', watch.onChange)
-  }
   connect.server(opts, function () {
     this.server.on('close', done)
-    if (onStart) onStart()
+    if (watchGlob && watchCall) watch(watchGlob, watchCall)
   })
 }
diff --git a/package.json b/package.json
index 423eec1..db3735f 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,6 @@
   "devDependencies": {
     "autoprefixer": "~9.4",
     "browserify": "~16.2",
-    "chokidar": "~2.0",
     "cssnano": "~4.1",
     "eslint": "~5.11",
     "eslint-config-standard": "~12.0",
diff --git a/yarn.lock b/yarn.lock
index c67fbba..524b64d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1107,7 +1107,7 @@ chardet@^0.7.0:
   resolved "https://registry.yarnpkg.com/chardet/-/chardet-0.7.0.tgz#90094849f0937f2eedc2425d0d28a9e5f0cbad9e"
   integrity sha512-mT8iDcrh03qDGRRmoA2hmBJnxpllMR+0/0qlzjqZES6NdiWDcZkCNAk4rPFZ9Q85r27unkiNNg8ZOiwZXBHwcA==
 
-chokidar@^2.0.0, chokidar@~2.0:
+chokidar@^2.0.0:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.0.4.tgz#356ff4e2b0e8e43e322d18a372460bbcf3accd26"
   integrity sha512-z9n7yt9rOvIJrMhvDtDictKrkFHeihkNl6uWMmZlmL6tJtX9Cs+87oK+teBx+JIgzvbX3yZHT3eF8vpbDxHJXQ==