Adds JSONHelper methods to read numbers as NSNumber objects.

MonsterCards/Helpers/JSONHelper.h

@@ -14,8 +14,13 @@ NS_ASSUME_NONNULL_BEGIN
 
 +(NSString*)readStringFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key;
 +(NSString*)readStringFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key withDefaultValue:(NSString* _Nullable)defaultValue;
++(NSNumber*)readNumberFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key;
++(NSNumber*)readNumberFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key withDefaultValue:(NSNumber* _Nullable)defaultValue;
 +(NSString*)readStringFromArray:(NSArray*)array forIndex:(NSUInteger)index;
 +(NSString*)readStringFromArray:(NSArray*)array forIndex:(NSUInteger)index withDefaultValue:(NSString* _Nullable)defaultValue;
++(NSNumber*)readNumberFromArray:(NSArray*)array forIndex:(NSUInteger)index;
++(NSNumber*)readNumberFromArray:(NSArray*)array forIndex:(NSUInteger)index withDefaultValue:(NSNumber* _Nullable)defaultValue;
+
 @end
 
 NS_ASSUME_NONNULL_END

MonsterCards/Helpers/JSONHelper.m

@@ -18,6 +18,14 @@ NSString* coerceObjectToString(NSObject *object, NSString *defaultValue) {
     return defaultValue;
 }
 
+NSNumber* coerceObjectToNumber(NSObject *object, NSNumber *defaultValue) {
+    if ([object isKindOfClass:[NSNumber class]]) {
+        return (NSNumber*)object;
+    }
+    
+    return defaultValue;
+}
+
 +(NSString*)readStringFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key {
     return [JSONHelper readStringFromDictionary:dictionary forKey:key withDefaultValue:nil];
 }
@@ -27,6 +35,15 @@ NSString* coerceObjectToString(NSObject *object, NSString *defaultValue) {
     return coerceObjectToString(object, defaultValue);
 }
 
++(NSNumber*)readNumberFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key {
+    return [JSONHelper readNumberFromDictionary:dictionary forKey:key withDefaultValue:nil];
+}
+
++(NSNumber*)readNumberFromDictionary:(NSDictionary*)dictionary forKey:(NSString*)key withDefaultValue:(NSNumber* _Nullable)defaultValue {
+    NSObject *object = [dictionary objectForKey:key];
+    return coerceObjectToNumber(object, defaultValue);
+}
+
 +(NSString*)readStringFromArray:(NSArray*)array forIndex:(NSUInteger)index{
     return [JSONHelper readStringFromArray:array forIndex:index withDefaultValue:nil];
 }
@@ -36,4 +53,13 @@ NSString* coerceObjectToString(NSObject *object, NSString *defaultValue) {
     return coerceObjectToString(object, defaultValue);
 }
 
++(NSNumber*)readNumberFromArray:(NSArray*)array forIndex:(NSUInteger)index {
+    return [JSONHelper readNumberFromArray:array forIndex:index withDefaultValue:nil];
+}
+
++(NSNumber*)readNumberFromArray:(NSArray*)array forIndex:(NSUInteger)index withDefaultValue:(NSNumber* _Nullable)defaultValue {
+    NSObject *object = [array objectAtIndex:index];
+    return coerceObjectToNumber(object, defaultValue);
+}
+
 @end

MonsterCardsTests/Helpers/JSONHelperTests.m

@@ -144,4 +144,90 @@ NSArray* readJSONArrayFromString(NSString *jsonString) {
     XCTAssertEqualObjects(_jsonStringValue, readString);
 }
 
+#pragma mark - Integers in Dictionaries
+
+- (void)testReadIntegerFromDictionaryReturnsNilIfKeyNotPresent {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonStringFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromDictionary:jsonRoot forKey:_jsonIntegerKey];
+    XCTAssertNil(readNumber);
+}
+
+- (void)testReadIntegerFromDictionaryWithDefaultReturnsDefaultIfKeyNotPresent {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonStringFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromDictionary:jsonRoot  forKey:_jsonIntegerKey withDefaultValue:_jsonIntegerValue];
+    XCTAssertEqualObjects(_jsonIntegerValue, readNumber);
+}
+
+- (void) testReadIntegerFromDictionaryReturnsCorrectValue {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonIntegerFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromDictionary:jsonRoot  forKey:_jsonIntegerKey];
+    XCTAssertEqualObjects(_jsonIntegerValue, readNumber);
+}
+
+- (void)testReadIntegerFromDictionaryWithDefaultReturnsCorrectValue {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonIntegerFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromDictionary:jsonRoot  forKey:_jsonIntegerKey withDefaultValue:@67890];
+    XCTAssertEqualObjects(_jsonIntegerValue, readNumber);
+}
+
+- (void) testReadIntegerFromDictionaryReturnsNilIfWrongType {
+    NSString *jsonString = [NSString stringWithFormat:@"{\"%@\":\"%@\"}", _jsonIntegerKey, _jsonStringValue];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromDictionary:jsonRoot  forKey:_jsonIntegerKey];
+    XCTAssertNil(readNumber);
+}
+
+#pragma mark - Integers in Arrays
+
+- (void)testReadIntegerFromArrayReturnsNilIfNotAnInteger {
+    NSString *jsonString = [NSString stringWithFormat:@"[\"%@\"]", _jsonStringValue];
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromArray:jsonRoot forIndex:0];
+    XCTAssertNil(readNumber);
+}
+
+- (void)testReadIntegerFromArrayWithDefaultReturnsDefaultValueIfNotAnInteger {
+    NSString *jsonString = [NSString stringWithFormat:@"[\"%@\"]", _jsonStringValue];
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromArray:jsonRoot forIndex:0 withDefaultValue:_jsonIntegerValue];
+    XCTAssertEqualObjects(_jsonIntegerValue, readNumber);
+}
+
+- (void)testReadIntegerFromArrayThrowsIfIndexOutOfRange {
+    // TODO: Decide if this should throw or return nil
+    NSString *jsonString = @"[]";
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    XCTAssertThrows([JSONHelper readNumberFromArray:jsonRoot forIndex:0]);
+    XCTAssertThrows([JSONHelper readNumberFromArray:jsonRoot forIndex:-1]);
+}
+
+- (void)testReadIntegerFromArrayReturnsCorrectValue {
+    NSString *jsonString = [NSString stringWithFormat:@"[%@]", _jsonIntegerValue];
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSNumber *readNumber = [JSONHelper readNumberFromArray:jsonRoot forIndex:0];
+    XCTAssertEqualObjects(_jsonIntegerValue, readNumber);
+}
+
 @end