Add watch options to copy command

Author: thenikso

lib/copy.js

@@ -1,20 +1,27 @@
 'use strict';
 
 const BbPromise = require('bluebird');
+const colors = require('colors/safe');
+const fse = require('fs-extra');
+const path = require('path');
 const glob = require('glob');
+const watchFiles = require('./utils/watch');
 const relative = require('./utils/relative-path');
 
-module.exports = (args) => BbPromise.resolve(args).then(args => {
-  const colors = require('colors/safe');
-  const fse = require('fs-extra');
-  const path = require('path');
+const copyWatcher = (fromDir, toDir) => (watcher) => watcher.on('changed', (filePath) => {
+  const toPath = path.join(toDir, path.relative(fromDir, filePath));
+  fse.copySync(filePath, toPath);
+  console.log(`  Copying ${colors.gray(filePath)} to ${colors.gray(toPath)}`);
+});
 
+module.exports = (args) => BbPromise.resolve(args).then(args => {
   console.log(colors.yellow('Copy...'));
 
   const options = Object.assign(
     {
       package: './package.json',
       outDir: './dist',
+      watch: false,
     },
     args || {}
   );
@@ -26,6 +33,7 @@ module.exports = (args) => BbPromise.resolve(args).then(args => {
     console.log('  Copy package json in dist directory as well as static files.');
     console.log(`  ${colors.gray('package')}: The npm package.json (${options.package})`);
     console.log(`  ${colors.gray('outDir')}: The output directory (${options.outDir})`);
+    console.log(`  ${colors.gray('watch')}: Copy again on files changes (${options.watch})`);
     return args;
   }
 
@@ -49,6 +57,9 @@ module.exports = (args) => BbPromise.resolve(args).then(args => {
         const toPath = relative(copyGlobs);
         console.log(`  Copying ${colors.gray(fromPath)} to ${colors.gray(toPath)}`);
         fse.copySync(fromPath, toPath);
+        if (options.watch) {
+          watchFiles(path.join(fromPath, '*')).then(copyWatcher(fromPath, toPath));
+        }
       } else {
         // copyGlobs has the form { 'glob': 'dest folder' }
         for (let sourceGlob in copyGlobs) {
@@ -59,6 +70,9 @@ module.exports = (args) => BbPromise.resolve(args).then(args => {
             .map((src) => ([src, path.join(toPath, path.relative(fromPath, src))]))
             .forEach((srcDst) => fse.copySync.apply(null, srcDst));
           console.log(`  Copying ${colors.gray(fromGlob)} to ${colors.gray(toPath)}`);
+          if (options.watch) {
+            watchFiles(fromGlob).then(copyWatcher(fromPath, toPath));
+          }
         }
       }
     }