Better support for command line arguments, see #1459

js/grunt/Gruntfile.js

@@ -151,7 +151,7 @@ Minify-specific options:
  --minify.stripAssertions=false - During uglification, it will strip assertions.
  --minify.stripLogging=false - During uglification, it will not strip logging statements.
  `,
-    wrapExecSync( `node ../chipper/js/grunt/tasks/build.js --repo ${repo}` )
+    wrapExecSync( `node ../chipper/js/grunt/tasks/build.js --repo ${repo} ${process.argv.slice( 2 ).join( ' ' )}` )
   );
 
   grunt.registerTask( 'generate-used-strings-file',

js/grunt/tasks/build.js

@@ -20,6 +20,25 @@ const assert = require( 'assert' );
 const Transpiler = require( '../../common/Transpiler' );
 const getBrands = require( './getBrands' );
 
+// Like minimist, process into an object literal which can be consumed by grunt.option.init
+function parseArgs( argv ) {
+  const args = {};
+  argv.forEach( ( arg, index ) => {
+    if ( arg.startsWith( '--' ) ) {
+      const key = arg.slice( 2 );
+      const value = argv[ index + 1 ] && !argv[ index + 1 ].startsWith( '--' ) ? argv[ index + 1 ] : true;
+      args[ key ] = value;
+    }
+  } );
+  return args;
+}
+
+// Parse argv
+const parsedArgs = parseArgs( process.argv.slice( 2 ) );
+
+// Initialize Grunt options with parsed arguments
+grunt.option.init( parsedArgs );
+
 const repo = getRequiredArg( '--repo' );
 
 const transpiler = new Transpiler( { silent: true } );