refactor: throw fatal error if provider not configured

Author: russellwheatley

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/AuthServiceError.swift

@@ -17,7 +17,6 @@ public struct AccountMergeConflictContext: LocalizedError {
 public enum AuthServiceError: LocalizedError {
   case noCurrentUser
   case invalidEmailLink(String)
-  case notConfiguredProvider(String)
   case clientIdNotFound(String)
   case notConfiguredActionCodeSettings(String)
   case reauthenticationRequired(String)
@@ -31,8 +30,6 @@ public enum AuthServiceError: LocalizedError {
       return "No user is currently signed in."
     case let .invalidEmailLink(description):
       return description
-    case let .notConfiguredProvider(description):
-      return description
     case let .clientIdNotFound(description):
       return description
     case let .notConfiguredActionCodeSettings(description):

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/Services/AuthService.swift

@@ -120,8 +120,7 @@ public final class AuthService {
   private var googleProvider: any GoogleProviderAuthUIProtocol {
     get throws {
       guard let provider = unsafeGoogleProvider else {
-        throw AuthServiceError
-          .notConfiguredProvider("`GoogleProviderSwift` has not been configured")
+        fatalError("`GoogleProviderAuthUI` has not been configured")
       }
       return provider
     }
@@ -130,8 +129,7 @@ public final class AuthService {
   private var facebookProvider: any FacebookProviderAuthUIProtocol {
     get throws {
       guard let provider = unsafeFacebookProvider else {
-        throw AuthServiceError
-          .notConfiguredProvider("`FacebookProviderAuthUI` has not been configured")
+        fatalError("`FacebookProviderAuthUI` has not been configured")
       }
       return provider
     }
@@ -140,8 +138,7 @@ public final class AuthService {
   private var phoneAuthProvider: any PhoneAuthProviderAuthUIProtocol {
     get throws {
       guard let provider = unsafePhoneAuthProvider else {
-        throw AuthServiceError
-          .notConfiguredProvider("`PhoneAuthProviderSwift` has not been configured")
+        fatalError("`PhoneAuthProviderAuthUI` has not been configured")
       }
       return provider
     }