Add a private method restorePreviousSignInNoRefresh in GIDSignIn.

GoogleSignIn/Sources/GIDGoogleUser.m

@@ -39,7 +39,7 @@
 @implementation GIDGoogleUser
 
 - (instancetype)initWithAuthState:(OIDAuthState *)authState
-                      profileData:(GIDProfileData *)profileData {
+                      profileData:(nullable GIDProfileData *)profileData {
   self = [super init];
   if (self) {
     _authentication = [[GIDAuthentication alloc] initWithAuthState:authState];

GoogleSignIn/Sources/GIDGoogleUser_Private.h

@@ -25,7 +25,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 // Create a object with an auth state, scopes, and profile data.
 - (instancetype)initWithAuthState:(OIDAuthState *)authState
-                      profileData:(GIDProfileData *)profileData;
+                      profileData:(nullable GIDProfileData *)profileData;
 
 @end
 

GoogleSignIn/Sources/GIDSignIn.m

@@ -186,6 +186,17 @@ - (BOOL)hasPreviousSignIn {
   return [authState isAuthorized];
 }
 
+- (nullable GIDGoogleUser *)restoredGoogleUserFromPreviousSignIn {
+  OIDAuthState *authState = [self loadAuthState];
+
+  if (!authState) {
+    return nil;
+  }
+
+  return [[GIDGoogleUser alloc] initWithAuthState:authState
+                                      profileData:nil];
+}
+
 - (void)restorePreviousSignIn {
   [self signInWithOptions:[GIDSignInInternalOptions silentOptions]];
 }

GoogleSignIn/Sources/GIDSignIn_Private.h

@@ -18,6 +18,7 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+@class GIDGoogleUser;
 @class GIDSignInInternalOptions;
 
 // Private |GIDSignIn| methods that are used internally in this SDK and other Google SDKs.
@@ -29,6 +30,9 @@ NS_ASSUME_NONNULL_BEGIN
 // Authenticates with extra options.
 - (void)signInWithOptions:(GIDSignInInternalOptions *)options;
 
+// Returns the previous sign-in user in the keychain without refreshing the access token.
+- (nullable GIDGoogleUser *)restoredGoogleUserFromPreviousSignIn;
+
 @end
 
 NS_ASSUME_NONNULL_END

GoogleSignIn/Tests/Unit/GIDSignInTest.m

@@ -66,6 +66,8 @@
     return YES;\
 }]
 
+static NSString * const kFakeGaiaID = @"123456789";
+static NSString * const kFakeIDToken = @"FakeIDToken";
 static NSString * const kClientId = @"FakeClientID";
 static NSString * const kDotReversedClientId = @"FakeClientID";
 static NSString * const kClientId2 = @"FakeClientID2";
@@ -347,6 +349,35 @@ - (void)testDefaultScope {
   [_signIn startMocking];
 }
 
+- (void)testRestoredGoogleUserFromPreviousSignIn_hasPreviousUser {
+  [[[_authorization expect] andReturn:_authState] authState];
+  OCMStub([_authState lastTokenResponse]).andReturn(_tokenResponse);
+  OCMStub([_tokenResponse scope]).andReturn(nil);
+  OCMStub([_tokenResponse additionalParameters]).andReturn(nil);
+  OCMStub([_tokenResponse idToken]).andReturn(kFakeIDToken);
+
+  id idTokenDecoded = OCMClassMock([OIDIDToken class]);
+  OCMStub([idTokenDecoded alloc]).andReturn(idTokenDecoded);
+  OCMStub([idTokenDecoded initWithIDTokenString:OCMOCK_ANY]).andReturn(idTokenDecoded);
+  OCMStub([idTokenDecoded subject]).andReturn(kFakeGaiaID);
+
+  GIDGoogleUser *previousUser = [_signIn restoredGoogleUserFromPreviousSignIn];
+
+  [_authorization verify];
+  [_authState verify];
+  [_tokenResponse verify];
+  XCTAssertEqual(previousUser.userID, kFakeGaiaID);
+}
+
+- (void)testRestoredGoogleUserFromPreviousSignIn_hasNoPreviousUser {
+  [[[_authorization expect] andReturn:nil] authState];
+
+  GIDGoogleUser *previousUser = [_signIn restoredGoogleUserFromPreviousSignIn];
+
+  [_authorization verify];
+  XCTAssertNil(previousUser);
+}
+
 - (void)testHasPreviousSignIn_HasBeenAuthenticated {
   [[[_authorization expect] andReturn:_authState] authState];
   [[[_authState expect] andReturnValue:[NSNumber numberWithBool:YES]] isAuthorized];