Adds JSONHelper methods to read strings. (+1 squashed commit)

Squashed commits: [30b0a71] Adds JSONHelper methods to read strings.
2020-09-13 05:04:22 -07:00
parent 42baec2a38
commit bc23b55429
4 changed files with 227 additions and 0 deletions
--- a/MonsterCardsTests/Helpers/JSONHelperTests.m
+++ b/MonsterCardsTests/Helpers/JSONHelperTests.m
@@ -0,0 +1,147 @@
+//
+//  JSONHelperTests.m
+//  MonsterCardsTests
+//
+//  Created by Tom Hicks on 9/15/20.
+//  Copyright © 2020 Tom Hicks. All rights reserved.
+//
+
+#import <XCTest/XCTest.h>
+#import "JSONHelper.h"
+
+@interface JSONHelperTests : XCTestCase
+
+@end
+
+@implementation JSONHelperTests {
+    NSString *_jsonStringKey;
+    NSString *_jsonStringValue;
+    NSString *_jsonStringFragment;
+    NSString *_jsonIntegerKey;
+    NSNumber *_jsonIntegerValue;
+    NSString *_jsonIntegerFragment;
+}
+
+NSString* escapeStringForJSON(NSString *unescaped) {
+    return [[unescaped stringByReplacingOccurrencesOfString:@"\\" withString:@"\\\\"] stringByReplacingOccurrencesOfString:@"\"" withString:@"\\\""];
+}
+
+NSDictionary* readJSONDictionaryFromString(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* readJSONArrayFromString(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;
+    }
+}
+
+- (void)setUp {
+    _jsonStringKey = @"my_string";
+    _jsonStringValue = @"Hello, World!";
+    _jsonStringFragment = [NSString stringWithFormat:@"\"%@\":\"%@\"", escapeStringForJSON(_jsonStringKey), escapeStringForJSON(_jsonStringValue)];
+    _jsonIntegerKey = @"my_int";
+    _jsonIntegerValue = @12345;
+    _jsonIntegerFragment = [NSString stringWithFormat:@"\"%@\":%@", escapeStringForJSON(_jsonIntegerKey), [_jsonIntegerValue stringValue]];
+}
+
+- (void)tearDown {
+}
+
+#pragma mark - Strings in Dictionaries
+
+- (void)testReadStringFromDictionaryReturnsNilIfKeyNotPresent {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonIntegerFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromDictionary:jsonRoot  forKey:_jsonStringKey];
+    XCTAssertNil(readString);
+}
+
+- (void)testReadStringFromDictionaryWithDefaultReturnsDefaultIfKeyNotPresent {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonIntegerFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromDictionary:jsonRoot  forKey:_jsonStringKey withDefaultValue:_jsonStringValue];
+    XCTAssertEqualObjects(_jsonStringValue, readString);
+}
+
+- (void) testReadStringFromDictionaryReturnsCorrectValue {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonStringFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromDictionary:jsonRoot  forKey:_jsonStringKey];
+    XCTAssertEqualObjects(_jsonStringValue, readString);
+}
+
+- (void)testReadStringFromDictionaryWithDefaultReturnsCorrectValue {
+    NSString *jsonString = [NSString stringWithFormat:@"{%@}", _jsonStringFragment];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromDictionary:jsonRoot  forKey:_jsonStringKey withDefaultValue:@"Some other string"];
+    XCTAssertEqualObjects(_jsonStringValue, readString);
+}
+
+- (void) testReadStringFromDictionaryReturnsNilIfWrongType {
+    NSString *jsonString = [NSString stringWithFormat:@"{\"%@\":%@}", _jsonStringKey, _jsonIntegerValue];
+    NSDictionary *jsonRoot = readJSONDictionaryFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromDictionary:jsonRoot  forKey:_jsonStringKey];
+    XCTAssertNil(readString);
+}
+
+#pragma mark - Strings in Arrays
+
+- (void)testReadStringFromArrayReturnsNilIfNotAString {
+    NSString *jsonString = [NSString stringWithFormat:@"[%@]", _jsonIntegerValue];
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromArray:jsonRoot forIndex:0];
+    XCTAssertNil(readString);
+}
+
+- (void)testReadStringFromArrayWithDefaultReturnsDefaultValueIfNotAString {
+    NSString *jsonString = [NSString stringWithFormat:@"[%@]", _jsonIntegerValue];
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromArray:jsonRoot forIndex:0 withDefaultValue:_jsonStringValue];
+    XCTAssertEqualObjects(_jsonStringValue, readString);
+}
+
+- (void)testReadStringFromArrayThrowsIfIndexOutOfRange {
+    // TODO: Decide if this should throw or return nil
+    NSString *jsonString = @"[]";
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    XCTAssertThrows([JSONHelper readStringFromArray:jsonRoot forIndex:0]);
+    XCTAssertThrows([JSONHelper readStringFromArray:jsonRoot forIndex:-1]);
+}
+
+- (void)testReadStringFromArrayReturnsCorrectValue {
+    NSString *jsonString = [NSString stringWithFormat:@"[\"%@\"]", _jsonStringValue];
+    NSArray *jsonRoot = readJSONArrayFromString(jsonString);
+    XCTAssertNotNil(jsonRoot);
+    
+    NSString *readString = [JSONHelper readStringFromArray:jsonRoot forIndex:0];
+    XCTAssertEqualObjects(_jsonStringValue, readString);
+}
+
+@end