fix(auth): allow removing and adding identity pool for an already deployed app

Author: harsh62

AmplifyPlugins/Auth/Sources/AWSCognitoAuthPlugin/CredentialStorage/AWSCognitoAuthCredentialStore.swift

@@ -83,8 +83,9 @@ struct AWSCognitoAuthCredentialStore {
         let oldUserPoolConfiguration = oldAuthConfigData.getUserPoolConfiguration()
         let oldIdentityPoolConfiguration = oldAuthConfigData.getIdentityPoolConfiguration()
         let newIdentityConfigData = currentAuthConfig.getIdentityPoolConfiguration()
+        let newUserPoolConfiguration = currentAuthConfig.getUserPoolConfiguration()
 
-        /// Only migrate if
+        /// Migrate if
         ///  - Old User Pool Config didn't exist
         ///  - New Identity Config Data exists
         ///  - Old Identity Pool Config == New Identity Pool Config
@@ -95,6 +96,19 @@ struct AWSCognitoAuthCredentialStore {
             if let oldCognitoCredentialsData = try? keychain._getData(oldNameSpace) {
                 try? keychain._set(oldCognitoCredentialsData, key: newNameSpace)
             }
+        /// Migrate if
+        ///  - Old config and new config are different
+        ///  - Old Userpool Existed
+        ///  - Old and new user pool namespacing is the same
+        } else if oldAuthConfigData != currentAuthConfig &&
+                    oldUserPoolConfiguration != nil &&
+                    UserPoolConfigurationData.isNamespacingEqual(
+                        lhs: oldUserPoolConfiguration,
+                        rhs: newUserPoolConfiguration) {
+            // retrieve data from the old namespace and save with the new namespace
+            if let oldCognitoCredentialsData = try? keychain._getData(oldNameSpace) {
+                try? keychain._set(oldCognitoCredentialsData, key: newNameSpace)
+            }
         } else if oldAuthConfigData != currentAuthConfig &&
                     oldNameSpace != newNameSpace {
             // Clear the old credentials

AmplifyPlugins/Auth/Sources/AWSCognitoAuthPlugin/StateMachine/CodeGen/Data/UserPoolConfigurationData.swift

@@ -57,6 +57,14 @@ struct UserPoolConfigurationData: Equatable {
     func getIdentityProviderName() -> String {
         return "cognito-idp.\(region).amazonaws.com/\(poolId)"
     }
+
+    static func isNamespacingEqual(
+        lhs: UserPoolConfigurationData?,
+        rhs: UserPoolConfigurationData?) -> Bool {
+            return lhs?.poolId == rhs?.poolId
+            && lhs?.clientId == rhs?.clientId
+            && lhs?.region == rhs?.region
+        }
 }
 
 extension UserPoolConfigurationData: Codable { }