Adds JSONHelper methods to make parsing json from strings and NSData objects easier.

MonsterCards/Helpers/JSONHelper.h

@@ -38,6 +38,14 @@ NS_ASSUME_NONNULL_BEGIN
 +(NSArray*)readArrayFromArray:(NSArray*)array forIndex:(NSUInteger)index;
 +(NSArray*)readArrayFromArray:(NSArray*)array forIndex:(NSUInteger)index withDefaultValue:(NSArray* _Nullable)defaultValue;
 
++(id)parseJSONString:(NSString*)jsonString;
++(NSDictionary*)parseJSONStringAsDictionary:(NSString*)jsonString;
++(NSArray*)parseJSONStringAsArray:(NSString*)jsonString;
+
++(id)parseJSONData:(NSData*)jsonData;
++(NSDictionary*)parseJSONDataAsDictionary:(NSData*)jsonData;
++(NSArray*)parseJSONDataAsArray:(NSData*)jsonData;
+
 @end
 
 NS_ASSUME_NONNULL_END

MonsterCards/Helpers/JSONHelper.m

@@ -175,4 +175,53 @@ BOOL coerceObjectToBool(NSObject *object, BOOL defaultValue) {
     return defaultValue;
 }
 
++(id)parseJSONString:(NSString*)jsonString {
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    NSArray *jsonRoot = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
+    return jsonRoot;
+}
+
++(NSDictionary*)parseJSONStringAsDictionary:(NSString*)jsonString {
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    NSDictionary *jsonRoot = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
+    if (![jsonRoot isKindOfClass:[NSDictionary class]]) {
+        return nil;
+    } else {
+        return jsonRoot;
+    }
+}
+
++(NSArray*)parseJSONStringAsArray:(NSString*)jsonString {
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    NSArray *jsonRoot = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
+    if (![jsonRoot isKindOfClass:[NSArray class]]) {
+        return nil;
+    } else {
+        return jsonRoot;
+    }
+}
+
++(id)parseJSONData:(NSData*)jsonData {
+    NSArray *jsonRoot = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
+    return jsonRoot;
+}
+
++(NSDictionary*)parseJSONDataAsDictionary:(NSData*)jsonData {
+    NSDictionary *jsonRoot = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
+    if (![jsonRoot isKindOfClass:[NSDictionary class]]) {
+        return nil;
+    } else {
+        return jsonRoot;
+    }
+}
+
++(NSArray*)parseJSONDataAsArray:(NSData*)jsonData {
+    NSArray *jsonRoot = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
+    if (![jsonRoot isKindOfClass:[NSArray class]]) {
+        return nil;
+    } else {
+        return jsonRoot;
+    }
+}
+
 @end

MonsterCardsTests/Helpers/JSONHelperTests.m

@@ -594,4 +594,104 @@ NSArray* readJSONArrayFromString(NSString *jsonString) {
     XCTAssertEqualObjects(_jsonArrayValue, readValue);
 }
 
+#pragma mark - JSON parsing
+
+- (void)testParseJSONDataReturnsDictionary {
+    NSString *jsonString = @"{\"a\":1,\"b\":2}";
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    
+    id parsedResult = [JSONHelper parseJSONData:jsonData];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSDictionary class]]);
+}
+
+- (void)testParseJSONDataReturnsArray {
+    NSString *jsonString = @"[\"a\",1,\"b\",2]";
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    
+    id parsedResult = [JSONHelper parseJSONData:jsonData];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSArray class]]);
+}
+
+- (void)testParseJSONDataAsDictionaryReturnsDictionary {
+    NSString *jsonString = @"{\"a\":1,\"b\":2}";
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    
+    NSDictionary *parsedResult = [JSONHelper parseJSONDataAsDictionary:jsonData];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSDictionary class]]);
+}
+
+- (void)testParseJSONDataAsDictionaryReturnsNilIfNotDictionary {
+    NSString *jsonString = @"[\"a\",1,\"b\",2]";
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    
+    id parsedResult = [JSONHelper parseJSONDataAsDictionary:jsonData];
+    XCTAssertNil(parsedResult);
+}
+
+- (void)testParseJSONDataAsArrayReturnsArray {
+    NSString *jsonString = @"[\"a\",1,\"b\",2]";
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    
+    id parsedResult = [JSONHelper parseJSONDataAsArray:jsonData];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSArray class]]);
+}
+
+- (void)testParseJSONDataAsArrayReturnsNilIfNotArray {
+    NSString *jsonString = @"{\"a\":1,\"b\":2}";
+    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+    
+    id parsedResult = [JSONHelper parseJSONDataAsArray:jsonData];
+    XCTAssertNil(parsedResult);
+}
+
+- (void)testParseJSONStringReturnsDictionary {
+    NSString *jsonString = @"{\"a\":1,\"b\":2}";
+    
+    id parsedResult = [JSONHelper parseJSONString:jsonString];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSDictionary class]]);
+}
+
+- (void)testParseJSONStringReturnsArray {
+    NSString *jsonString = @"[\"a\",1,\"b\",2]";
+    
+    id parsedResult = [JSONHelper parseJSONString:jsonString];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSArray class]]);
+}
+
+- (void)testParseJSONStringAsDictionaryReturnsDictionary {
+    NSString *jsonString = @"{\"a\":1,\"b\":2}";
+    
+    NSDictionary *parsedResult = [JSONHelper parseJSONStringAsDictionary:jsonString];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSDictionary class]]);
+}
+
+- (void)testParseJSONStringAsDictionaryReturnsNilIfNotDictionary {
+    NSString *jsonString = @"[\"a\",1,\"b\",2]";
+    
+    id parsedResult = [JSONHelper parseJSONStringAsDictionary:jsonString];
+    XCTAssertNil(parsedResult);
+}
+
+- (void)testParseJSONStringAsArrayReturnsArray {
+    NSString *jsonString = @"[\"a\",1,\"b\",2]";
+    
+    id parsedResult = [JSONHelper parseJSONStringAsArray:jsonString];
+    XCTAssertNotNil(parsedResult);
+    XCTAssertTrue([parsedResult isKindOfClass:[NSArray class]]);
+}
+
+- (void)testParseJSONStringAsArrayReturnsNilIfNotArray {
+    NSString *jsonString = @"{\"a\":1,\"b\":2}";
+    
+    id parsedResult = [JSONHelper parseJSONStringAsArray:jsonString];
+    XCTAssertNil(parsedResult);
+}
+
 @end