Fix leak of LanguageMode objects in tests

src/package-manager.js

@@ -90,6 +90,7 @@ module.exports = class PackageManager {
     this.packagesCache = packageJSON._atomPackages != null ? packageJSON._atomPackages : {}
     this.packageDependencies = packageJSON.packageDependencies != null ? packageJSON.packageDependencies : {}
     this.triggeredActivationHooks.clear()
+    this.activatePromise = null
   }
 
   /*
@@ -114,6 +115,14 @@ module.exports = class PackageManager {
     return this.emitter.on('did-activate-initial-packages', callback)
   }
 
+  getActivatePromise() {
+    if (this.activatePromise) {
+      return this.activatePromise
+    } else {
+      return Promise.resolve()
+    }
+  }
+
   // Public: Invoke the given callback when a package is activated.
   //
   // * `callback` A {Function} to be invoked when a package is activated.
@@ -659,10 +668,11 @@ module.exports = class PackageManager {
       const packages = this.getLoadedPackagesForTypes(types)
       promises = promises.concat(activator.activatePackages(packages))
     }
-    return Promise.all(promises).then(() => {
+    this.activatePromise = Promise.all(promises).then(() => {
       this.triggerDeferredActivationHooks()
       this.initialPackagesActivated = true
       this.emitter.emit('did-activate-initial-packages')
+      this.activatePromise = null
     })
   }
 

src/text-editor-registry.js

@@ -38,19 +38,10 @@ const EDITOR_PARAMS_BY_SETTING_KEY = [
 module.exports =
 class TextEditorRegistry {
   constructor ({config, assert, packageManager}) {
-    this.assert = assert
     this.config = config
+    this.assert = assert
+    this.packageManager = packageManager
     this.clear()
-
-    this.initialPackageActivationPromise = new Promise((resolve) => {
-      // TODO: Remove this usage of a private property of PackageManager.
-      // Should PackageManager just expose a promise-based API like this?
-      if (packageManager.deferredActivationHooks) {
-        packageManager.onDidActivateInitialPackages(resolve)
-      } else {
-        resolve()
-      }
-    })
   }
 
   deserialize (state) {
@@ -216,7 +207,7 @@ class TextEditorRegistry {
   }
 
   async updateAndMonitorEditorSettings (editor, oldLanguageMode) {
-    await this.initialPackageActivationPromise
+    await this.packageManager.getActivatePromise()
     this.updateEditorSettingsForLanguageMode(editor, oldLanguageMode)
     this.subscribeToSettingsForEditorScope(editor)
   }