fixup! Use await import in findBuildFile

lib/models/server-watcher.js

@@ -3,8 +3,8 @@
 const Watcher = require('./watcher');
 
 module.exports = class ServerWatcher extends Watcher {
-  constructor(options) {
-    super(options);
+  constructor(options, build) {
+    super(options, build);
 
     this.watcher.on('add', this.didAdd.bind(this));
     this.watcher.on('delete', this.didDelete.bind(this));

lib/models/watcher.js

@@ -12,10 +12,12 @@ const eventTypeNormalization = {
   change: 'changed',
 };
 
+const ConstructedFromBuilder = Symbol('Watcher.build');
+
 module.exports = class Watcher extends CoreObject {
   constructor(_options, build) {
-    if (!build) {
-      throw new Error('instantiate Watcher with await Watcher.build().watcher, not new Watcher()');
+    if (build !== ConstructedFromBuilder) {
+      throw new Error('instantiate Watcher with (await Watcher.build()).watcher, not new Watcher()');
     }
 
     super(_options);
@@ -25,9 +27,12 @@ module.exports = class Watcher extends CoreObject {
   }
 
   static async build(_options) {
-    let watcher = new Watcher(_options, true);
+    let watcher = new this(_options, ConstructedFromBuilder);
     await watcher.setupBroccoliWatcher(_options);
 
+    // This indirection is because Watcher instances are themselves spec
+    // noncompliant thennables (see the then() method) so returning watcher
+    // directly will interfere with `await Watcher.build()`
     return { watcher };
   }
 

tests/unit/models/server-watcher-test.js

@@ -12,12 +12,12 @@ describe('Server Watcher', function () {
   let analytics;
   let watcher;
 
-  beforeEach(function () {
+  beforeEach(async function () {
     ui = new MockUI();
     analytics = new MockAnalytics();
     watcher = new MockServerWatcher();
 
-    new ServerWatcher({
+    await ServerWatcher.build({
       ui,
       analytics,
       watcher,