[ITBL-4754] Fix an unhandled exception in response handling on network errors (#51)

Author: vbabenkoru

Iterable-iOS-SDK/IterableAPI.m

@@ -225,12 +225,24 @@ - (void)sendRequest:(NSURLRequest *)request onSuccess:(void (^)(NSDictionary *))
     {
         NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
         NSInteger responseCode = httpResponse.statusCode;
+
+        // Handle network errors
+        if (error != nil) {
+            NSString *reason = [NSString stringWithFormat:@"%@", error];
+            if (onFailure != nil) onFailure(reason, nil);
+            return;
+        }
 
         NSError *jsonError = nil;
-        id json = [NSJSONSerialization
-                     JSONObjectWithData:data
-                     options:0
-                     error:&jsonError];
+        id json = nil;
+
+        // Only try to parse JSON if data exists, otherwise JSONObjectWithData throws an exception
+        if ([data length] > 0) {
+            json = [NSJSONSerialization
+                    JSONObjectWithData:data
+                               options:0
+                                 error:&jsonError];
+        }
 
         if (responseCode == 401) {
             if (onFailure != nil) onFailure(@"Invalid API Key", data);
@@ -249,7 +261,7 @@ - (void)sendRequest:(NSURLRequest *)request onSuccess:(void (^)(NSDictionary *))
                 onFailure(errorMessage, data);
             }
         } else if (responseCode == 200) {
-            if ([data length] > 0 && error == nil) {
+            if ([data length] > 0) {
                 if (jsonError) {
                     NSString *reason = [NSString stringWithFormat:@"Could not parse json: %@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]];
                     if (onFailure != nil) onFailure(reason, data);
@@ -260,11 +272,8 @@ - (void)sendRequest:(NSURLRequest *)request onSuccess:(void (^)(NSDictionary *))
                 } else {
                     if (onFailure != nil) onFailure(@"Response is not a dictionary", data);
                 }
-            } else if ([data length] == 0 && error == nil) {
+            } else {
                 if (onFailure != nil) onFailure(@"No data received", data);
-            } else if (error != nil) {
-                NSString *reason = [NSString stringWithFormat:@"%@", error];
-                if (onFailure != nil) onFailure(reason, nil);
             }
         } else {
             if (onFailure != nil) onFailure([NSString stringWithFormat:@"Received non-200 response: %ld", (long) responseCode], data);

Iterable-iOS-SDKTests/IterableAPIResponseTests.m

@@ -159,4 +159,42 @@ - (void)testNon200ResponseCode {
     [self waitForExpectations:@[expectation] timeout:IterableResponseExpectationTimeout];
 }
 
+- (void)testNoNetworkResponse {
+    [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest * _Nonnull request) {
+        return YES;
+    } withStubResponse:^OHHTTPStubsResponse * _Nonnull(NSURLRequest * _Nonnull request) {
+        NSError* notConnectedError = [NSError errorWithDomain:NSURLErrorDomain code:kCFURLErrorNotConnectedToInternet userInfo:nil];
+        return [OHHTTPStubsResponse responseWithError:notConnectedError];
+    }];
+    
+    XCTestExpectation *expectation = [[XCTestExpectation alloc] initWithDescription:@"onFailure is called"];
+    
+    NSURLRequest *request = [[IterableAPI sharedInstance] createRequestForAction:@"" withArgs:@{}];
+    [[IterableAPI sharedInstance] sendRequest:request onSuccess:nil onFailure:^(NSString * _Nonnull reason, NSData * _Nullable data) {
+        [expectation fulfill];
+        XCTAssert([reason containsString:@"NSURLErrorDomain"]);
+    }];
+    [self waitForExpectations:@[expectation] timeout:IterableResponseExpectationTimeout];
+}
+
+- (void)testNetworkTimeoutResponse {
+    [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest * _Nonnull request) {
+        return YES;
+    } withStubResponse:^OHHTTPStubsResponse * _Nonnull(NSURLRequest * _Nonnull request) {
+        NSError* notConnectedError = [NSError errorWithDomain:NSURLErrorDomain code:kCFURLErrorNotConnectedToInternet userInfo:nil];
+        return [[OHHTTPStubsResponse responseWithData:nil statusCode:200 headers:nil] requestTime:0.0 responseTime:5.0];
+    }];
+    
+    XCTestExpectation *expectation = [[XCTestExpectation alloc] initWithDescription:@"onFailure is called"];
+    
+    NSMutableURLRequest *request = (NSMutableURLRequest *) [[IterableAPI sharedInstance] createRequestForAction:@"" withArgs:@{}];
+    request.timeoutInterval = 0.01;
+    [[IterableAPI sharedInstance] sendRequest:request onSuccess:nil onFailure:^(NSString * _Nonnull reason, NSData * _Nullable data) {
+        [expectation fulfill];
+        XCTAssert([reason containsString:@"NSURLErrorDomain"]);
+        XCTAssert([reason containsString:@"timed out"]);
+    }];
+    [self waitForExpectations:@[expectation] timeout:IterableResponseExpectationTimeout];
+}
+
 @end