Move src/shared/polyfills to src/boot/polyfills

The code in `polyfills/index.js` which determines which polyfills are
needed are compiled as part of the boot script and not used by other
parts of the application.

Because this code is compiled as part of the boot script it needs to be
compiled to parse in older browsers, even those which don't support the client
(eg. IE 10/11). Putting the `polyfills/` dir in side `src/boot` means
that it will inherit any custom Babel configuration for the `src/boot`
directory.

gulpfile.js

@@ -105,16 +105,16 @@ const appBundles = [
 //
 // To add a new polyfill:
 //  - Add the relevant dependencies to the project
-//  - Create an entry point in `src/shared/polyfills/{set}` and a feature
-//    detection function in `src/shared/polyfills/index.js`
+//  - Create an entry point in `src/boot/polyfills/{set}` and a feature
+//    detection function in `src/boot/polyfills/index.js`
 //  - Add the polyfill set name to the required dependencies for the parts of
 //    the client that need it in `src/boot/boot.js`
-const polyfillBundles = readdirSync('./src/shared/polyfills/')
+const polyfillBundles = readdirSync('./src/boot/polyfills/')
   .filter(name => name.endsWith('.js') && name !== 'index.js')
   .map(name => name.replace(/\.js$/, ''))
   .map(set => ({
     name: `polyfills-${set}`,
-    entry: `./src/shared/polyfills/${set}`,
+    entry: `./src/boot/polyfills/${set}`,
     transforms: ['babel'],
   }));
 

src/boot/boot.js

@@ -1,4 +1,4 @@
-import { requiredPolyfillSets } from '../shared/polyfills';
+import { requiredPolyfillSets } from './polyfills';
 
 /**
  * Polyfills used by both the annotator and sidebar app.

src/shared/polyfills/test/index-test.js → src/boot/polyfills/test/index-test.js

@@ -12,7 +12,7 @@ function stubOut(obj, property, replacement = undefined) {
   };
 }
 
-describe('shared/polyfills/index', () => {
+describe('boot/polyfills/index', () => {
   describe('requiredPolyfillSets', () => {
     let undoStub;
 

src/boot/test/boot-test.js

@@ -18,7 +18,7 @@ describe('bootstrap', function () {
     };
 
     $imports.$mock({
-      '../shared/polyfills': fakePolyfills,
+      './polyfills': fakePolyfills,
     });
   });
 

src/karma.config.js

@@ -106,7 +106,7 @@ module.exports = function (config) {
     // preprocess matching files before serving them to the browser
     // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
     preprocessors: {
-      './shared/polyfills/*.js': ['browserify'],
+      './boot/polyfills/*.js': ['browserify'],
       './sidebar/test/bootstrap.js': ['browserify'],
       '**/*-test.js': ['browserify'],
       '**/*-it.js': ['browserify'],