use closure 20171023, with proper ordering

Author: dfreedm

gulpfile.js

@@ -57,27 +57,24 @@ function closurify(sourceName, fileName) {
     js_output_file: `${fileName}.js`,
     warning_level: 'VERBOSE',
     rewrite_polyfills: false,
+    module_resolution: 'NODE',
     externs: [
       'externs/webcomponents.js',
       'node_modules/@webcomponents/custom-elements/externs/custom-elements.js',
       'node_modules/@webcomponents/html-imports/externs/html-imports.js',
       'node_modules/@webcomponents/shadycss/externs/shadycss-externs.js',
       'node_modules/@webcomponents/shadydom/externs/shadydom.js'
-    ]
+    ],
+    entry_point: `entrypoints/${sourceName}-index.js`,
+    dependency_mode: 'STRICT'
   };
 
-  const rollupOptions = {
-    entry: `entrypoints/${sourceName}-index.js`,
-    format: 'iife',
-    moduleName: 'webcomponents',
-    sourceMap: true,
-    context: 'window'
-  };
-
-  return rollup(rollupOptions)
-  .pipe(source(`${sourceName}-bundle.js`))
-  .pipe(buffer())
-  .pipe(sourcemaps.init({loadMaps: true}))
+  return gulp.src([
+    'entrypoints/*.js', 'src/*.js',
+    'node_modules/es6-promise/lib/**/*.js',
+    'node_modules/@webcomponents/**/*.js',
+    '!node_modules/@webcomponents/*/externs/*.js'
+  ], {base: './'})
   .pipe(closure(closureOptions))
   .pipe(sourcemaps.write('.'))
   .pipe(gulp.dest('.'));

package-lock.json

@@ -37,7 +37,7 @@
     "del": "^3.0.0",
     "es6-promise": "^4.1.1",
     "eslint": "^4.9.0",
-    "google-closure-compiler": "^20170910.0.0",
+    "google-closure-compiler": "^20171023.0.1",
     "gulp": "^3.8.8",
     "gulp-rename": "^1.2.2",
     "gulp-sourcemaps": "^2.4.1",