Add unit test for GIDDataFetcher

GoogleSignIn/Sources/GIDSignIn.m

@@ -123,9 +123,6 @@ static NSString *const kUserCanceledError = @"The user canceled the sign-in flow
 // User preference key to detect fresh install of the app.
 static NSString *const kAppHasRunBeforeKey = @"GID_AppHasRunBefore";
 
-// Maximum retry interval in seconds for the fetcher.
-static const NSTimeInterval kFetcherMaxRetryInterval = 15.0;
-
 // The delay before the new sign-in flow can be presented after the existing one is cancelled.
 static const NSTimeInterval kPresentationDelayAfterCancel = 1.0;
 
@@ -831,10 +828,10 @@ static NSString *const kConfigOpenIDRealmKey = @"GIDOpenIDRealm";
               [GIDSignInPreferences googleUserInfoServer],
               authState.lastTokenResponse.accessToken]];
       
-      [_dataFetcher startFetchURL:infoURL
-                    fromAuthState:authState
-                      withComment:@"GIDSignIn: fetch basic profile info"
-                       completion:^(NSData *data, NSError *error) {
+      [self->_dataFetcher startFetchURL:infoURL
+                          fromAuthState:authState
+                            withComment:@"GIDSignIn: fetch basic profile info"
+                             completion:^(NSData *data, NSError *error) {
         if (data && !error) {
           NSError *jsonDeserializationError;
           NSDictionary<NSString *, NSString *> *profileDict =

GoogleSignIn/Tests/Unit/GIDDataFetcherTest.m

@@ -0,0 +1,135 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#import "GoogleSignIn/Sources/GIDDataFetcher/Implementations/GIDDataFetcher.h"
+
+#import <XCTest/XCTest.h>
+
+#import "GoogleSignIn/Tests/Unit/GIDFakeFetcher.h"
+#import "GoogleSignIn/Tests/Unit/GIDFakeFetcherService.h"
+#import "GoogleSignIn/Tests/Unit/OIDAuthState+Testing.h"
+
+#ifdef SWIFT_PACKAGE
+@import AppAuth;
+@import GTMAppAuth;
+@import OCMock;
+#else
+#import <AppAuth/AppAuth.h>
+#import <GTMAppAuth/GTMAppAuth.h>
+#import <OCMock/OCMock.h>
+#endif
+
+static NSString *const kTestURL = @"testURL.com";
+static NSString * const kErrorDomain = @"ERROR_DOMAIN";
+static NSInteger const kErrorCode = 212;
+
+@interface GIDDataFetcherTest : XCTestCase {
+  GIDDataFetcher *_dataFetcher;
+  
+  // Mock |GTMAppAuthFetcherAuthorization|.
+  id _authorization;
+  
+  // Fake fetcher service to emulate network requests.
+  GIDFakeFetcherService *_fakeFetcherService;
+}
+
+@end
+
+@implementation GIDDataFetcherTest
+
+- (void)setUp {
+  [super setUp];
+  _dataFetcher = [[GIDDataFetcher alloc] init];
+  _fakeFetcherService = [[GIDFakeFetcherService alloc] init];
+  
+  _authorization = OCMStrictClassMock([GTMAppAuthFetcherAuthorization class]);
+  OCMStub([_authorization alloc]).andReturn(_authorization);
+  OCMStub([_authorization initWithAuthState:OCMOCK_ANY]).andReturn(_authorization);
+  OCMStub([_authorization fetcherService]).andReturn(_fakeFetcherService);
+}
+
+- (void)tearDown {
+  _authorization = nil;
+  [super tearDown];
+}
+
+- (void)testFetchData_success {
+  NSURL *url = [NSURL URLWithString:kTestURL];
+  OIDAuthState *authState = [OIDAuthState testInstance];
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:@"Callback called with no error"];
+
+  [_dataFetcher startFetchURL:url
+                fromAuthState:authState
+                  withComment:@"Test data fetcher."
+                   completion:^(NSData *data, NSError *error) {
+    if (error == nil) {
+      [expectation fulfill];
+    }
+  }];
+
+  XCTAssertTrue([self isFetcherStarted], @"should start fetching");
+  // Emulate result back from server.
+  [self didFetch:nil error:nil];
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+
+- (void)testFetchData_error {
+  NSURL *url = [NSURL URLWithString:kTestURL];
+  OIDAuthState *authState = [OIDAuthState testInstance];
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:@"Callback called with an error"];
+  [_dataFetcher startFetchURL:url
+                fromAuthState:authState
+                  withComment:@"Test data fetcher."
+                   completion:^(NSData *data, NSError *error) {
+    if (error != nil) {
+      [expectation fulfill];
+    }
+  }];
+
+  XCTAssertTrue([self isFetcherStarted], @"should start fetching");
+  // Emulate result back from server.
+  NSError *error = [self error];
+  [self didFetch:nil error:error];
+  [self waitForExpectationsWithTimeout:1 handler:nil];
+}
+
+#pragma mark - Helpers
+
+// Whether or not a fetcher has been started.
+- (BOOL)isFetcherStarted {
+  NSUInteger count = _fakeFetcherService.fetchers.count;
+  XCTAssertTrue(count <= 1, @"Only one fetcher is supported");
+  return !!count;
+}
+
+// Emulates server returning the data as in JSON.
+- (void)didFetch:(id)dataObject error:(NSError *)error {
+  NSData *data = nil;
+  if (dataObject) {
+    NSError *jsonError = nil;
+    data = [NSJSONSerialization dataWithJSONObject:dataObject
+                                           options:0
+                                             error:&jsonError];
+    XCTAssertNil(jsonError, @"must provide valid data");
+  }
+  [_fakeFetcherService.fetchers[0] didFinishWithData:data error:error];
+}
+
+- (NSError *)error {
+  return [NSError errorWithDomain:kErrorDomain code:kErrorCode userInfo:nil];
+}
+
+@end