Remove betaUI preference state, replace with completedUiMigration

app/scripts/controllers/preferences.js

@@ -33,10 +33,7 @@ class PreferencesController {
       tokens: [],
       suggestedTokens: {},
       useBlockie: false,
-      featureFlags: {
-        betaUI: true,
-        skipAnnounceBetaUI: true,
-      },
+      featureFlags: {},
       knownMethodData: {},
       currentLocale: opts.initLangCode,
       identities: {},
@@ -47,6 +44,7 @@ class PreferencesController {
         useNativeCurrencyAsPrimaryCurrency: true,
       },
       completedOnboarding: false,
+      completedUiMigration: false,
     }, opts.initState)
 
     this.diagnostics = opts.diagnostics
@@ -552,6 +550,14 @@ class PreferencesController {
     return Promise.resolve(true)
   }
 
+  /**
+   * Sets the {@code completedUiMigration} state to {@code true}, indicating that the user has completed the UI switch.
+   */
+  completeUiMigration () {
+    this.store.updateState({ completedUiMigration: true })
+    return Promise.resolve(true)
+  }
+
   //
   // PRIVATE METHODS
   //

app/scripts/migrations/032.js

@@ -0,0 +1,29 @@
+const version = 32
+const clone = require('clone')
+
+/**
+ * The purpose of this migration is to set the {@code completedUiMigration} flag based on the user's UI preferences
+ */
+module.exports = {
+  version,
+  migrate: async function (originalVersionedData) {
+    const versionedData = clone(originalVersionedData)
+    versionedData.meta.version = version
+    const state = versionedData.data
+    versionedData.data = transformState(state)
+    return versionedData
+  },
+}
+
+function transformState (state) {
+  const { PreferencesController } = state
+
+  if (PreferencesController) {
+    const { betaUI } = PreferencesController.featureFlags || {}
+    // Users who have been using the "beta" UI are considered to have completed the migration
+    // as they'll see no difference in this version
+    PreferencesController.completedUiMigration = betaUI
+  }
+
+  return state
+}

test/unit/ui/app/reducers/metamask.spec.js

@@ -502,17 +502,15 @@ describe('MetaMask Reducers', () => {
     assert.equal(state.useBlockie, true)
   })
 
-  it('updates feature flag', () => {
+  it('updates an arbitrary feature flag', () => {
     const state = reduceMetamask({}, {
       type: actions.UPDATE_FEATURE_FLAGS,
       value: {
-        betaUI: true,
-        skipAnnounceBetaUI: true,
+        foo: true,
       },
     })
 
-    assert.equal(state.featureFlags.betaUI, true)
-    assert.equal(state.featureFlags.skipAnnounceBetaUI, true)
+    assert.equal(state.featureFlags.foo, true)
   })
 
   it('updates network endpoint type', () => {