From f903eedc152ef16440b203fdaef1f05e32e6fd71 Mon Sep 17 00:00:00 2001
From: Jack Short <john.short.tj@gmail.com>
Date: Tue, 14 Nov 2023 13:29:17 -0500
Subject: [PATCH] fix: redux migration to flush german locale (#7584)

* fix: redux migration to flush german locale

* lint

* my linter was not workking
---
 src/state/migrations.test.ts   |  2 +-
 src/state/migrations.ts        |  2 ++
 src/state/migrations/4.test.ts | 46 ++++++++++++++++++++++++++++++++++
 src/state/migrations/4.ts      | 28 +++++++++++++++++++++
 src/state/reducer.ts           |  2 +-
 5 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 src/state/migrations/4.test.ts
 create mode 100644 src/state/migrations/4.ts

diff --git a/src/state/migrations.test.ts b/src/state/migrations.test.ts
index 070665a1f7..cec883cd38 100644
--- a/src/state/migrations.test.ts
+++ b/src/state/migrations.test.ts
@@ -14,7 +14,7 @@ const defaultState = {
   user: {},
   _persist: {
     rehydrated: true,
-    version: 3,
+    version: 4,
   },
   application: {
     chainId: null,
diff --git a/src/state/migrations.ts b/src/state/migrations.ts
index 7815412818..476edd6629 100644
--- a/src/state/migrations.ts
+++ b/src/state/migrations.ts
@@ -5,6 +5,7 @@ import { migration0 } from './migrations/0'
 import { migration1 } from './migrations/1'
 import { migration2 } from './migrations/2'
 import { migration3 } from './migrations/3'
+import { migration4 } from './migrations/4'
 import { legacyLocalStorageMigration } from './migrations/legacy'
 
 /**
@@ -21,6 +22,7 @@ export const migrations: MigrationManifest = {
   1: migration1,
   2: migration2,
   3: migration3,
+  4: migration4,
 }
 
 // We use a custom migration function for the initial state, because redux-persist
diff --git a/src/state/migrations/4.test.ts b/src/state/migrations/4.test.ts
new file mode 100644
index 0000000000..b3999e673b
--- /dev/null
+++ b/src/state/migrations/4.test.ts
@@ -0,0 +1,46 @@
+import { DEFAULT_LOCALE } from 'constants/locales'
+import { createMigrate } from 'redux-persist'
+import { RouterPreference } from 'state/routing/types'
+import { SlippageTolerance } from 'state/user/types'
+
+import { migration1 } from './1'
+import { migration2 } from './2'
+import { migration3 } from './3'
+import { migration4, PersistAppStateV4 } from './4'
+
+const previousState: PersistAppStateV4 = {
+  user: {
+    userLocale: 'de-DE',
+    userRouterPreference: RouterPreference.API,
+    userHideClosedPositions: false,
+    userSlippageTolerance: SlippageTolerance.Auto,
+    userSlippageToleranceHasBeenMigratedToAuto: true,
+    userDeadline: 1800,
+    tokens: {},
+    pairs: {},
+    timestamp: Date.now(),
+    hideAndroidAnnouncementBanner: false,
+  },
+  _persist: {
+    version: 3,
+    rehydrated: true,
+  },
+}
+
+describe('migration to v4', () => {
+  it('should migrate users who currently have German as their set locale', async () => {
+    const migrator = createMigrate(
+      {
+        1: migration1,
+        2: migration2,
+        3: migration3,
+        4: migration4,
+      },
+      { debug: false }
+    )
+    const result: any = await migrator(previousState, 4)
+    expect(result.user.userLocale).toEqual(DEFAULT_LOCALE)
+
+    expect(result?._persist.version).toEqual(4)
+  })
+})
diff --git a/src/state/migrations/4.ts b/src/state/migrations/4.ts
new file mode 100644
index 0000000000..a22112761a
--- /dev/null
+++ b/src/state/migrations/4.ts
@@ -0,0 +1,28 @@
+import { DEFAULT_LOCALE } from 'constants/locales'
+import { PersistState } from 'redux-persist'
+import { UserState } from 'state/user/reducer'
+
+export type PersistAppStateV4 = {
+  _persist: PersistState
+} & { user?: UserState }
+
+/**
+ * Migration to set german locale to default locale, after
+ * the german locale was removed from supported locales.
+ */
+export const migration4 = (state: PersistAppStateV4 | undefined) => {
+  if (state?.user) {
+    if (state.user.userLocale === 'de-DE') {
+      state.user.userLocale = DEFAULT_LOCALE
+    }
+
+    return {
+      ...state,
+      _persist: {
+        ...state._persist,
+        version: 4,
+      },
+    }
+  }
+  return state
+}
diff --git a/src/state/reducer.ts b/src/state/reducer.ts
index 5cf65cf015..6591c1ffed 100644
--- a/src/state/reducer.ts
+++ b/src/state/reducer.ts
@@ -44,7 +44,7 @@ export type AppState = ReturnType<typeof appReducer>
 
 const persistConfig: PersistConfig<AppState> = {
   key: 'interface',
-  version: 3, // see migrations.ts for more details about this version
+  version: 4, // see migrations.ts for more details about this version
   storage: localForage.createInstance({
     name: 'redux',
   }),