Add caching helpers to the RKTestHelpers interface

Code/Testing/RKTestFactory.m

@@ -240,6 +240,9 @@ static RKTestFactory *sharedFactory = nil;
     if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {
         [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
     }
+    
+    // Clear the NSURLCache
+    [[NSURLCache sharedURLCache] removeAllCachedResponses];
 
     if ([self respondsToSelector:@selector(didSetUp)]) {
         [self didSetUp];
@@ -248,8 +251,9 @@ static RKTestFactory *sharedFactory = nil;
 
 + (void)tearDown
 {
-    // Cancel any network operations
+    // Cancel any network operations and clear the cache
     [[RKObjectManager sharedManager].operationQueue cancelAllOperations];
+    [[NSURLCache sharedURLCache] removeAllCachedResponses];
     
     // Ensure the existing defaultStore is shut down
     [[NSNotificationCenter defaultCenter] removeObserver:[RKManagedObjectStore defaultStore]];

Code/Testing/RKTestHelpers.h

@@ -83,17 +83,32 @@
                    toBlocksMatchingRelativeString:(NSString *)relativeString
                       onObjectManager:(RKObjectManager *)nilOrObjectManager;
 
-///-------------------------------
-/// @name Clearing the NSURL Cache
-///-------------------------------
+///-----------------------------
+/// @name Working with the Cache
+///-----------------------------
 
 /**
- Clears the contents of the cache directory by removing the directory and recreating it.
- 
- This has the effect of clearing any `NSCachedURLResponse` objects stored by `NSURLCache` as well as any application specific cache data.
- 
- @see `RKCachesDirectory()`
+ Disables caching by setting a new `[NSURLCache sharedURLCache]` instance in which the memory and disk limits have been set to zero.
  */
-+ (void)clearCacheDirectory;
++ (void)disableCaching;
+
+/**
+ Creates, stores, and returns a `NSCachedURLResponse` object containing an `NSHTTPURLResponse` for the given request with a 200 (OK) status code.
+ 
+ @param request The request to cache the response for.
+ @param responseData The response data to be stored in the cache.
+ @return The cached URL response that was stored to the cache.
+ */
++ (NSCachedURLResponse *)cacheResponseForRequest:(NSURLRequest *)request withResponseData:(NSData *)responseData;
+
+/**
+ Creates, stores, and returns a `NSCachedURLResponse` object containing an `NSHTTPURLResponse` for the given URL and HTTP method with the given response data and a 200 (OK) status code.
+ 
+ @param URL The URL to cache the response for.
+ @param HTTPMethod The HTTP method of the request (i.e. 'GET', 'POST', 'PUT', 'PATCH', or 'DELETE').
+ @param responseData The response data to be stored in the cache.
+ @return The cached URL response that was stored to the cache.
+ */
++ (NSCachedURLResponse *)cacheResponseForURL:(NSURL *)URL HTTPMethod:(NSString *)HTTPMethod headers:(NSDictionary *)requestHeaders withData:(NSData *)responseData;
 
 @end

Code/Testing/RKTestHelpers.m

@@ -86,23 +86,39 @@
     }
 }
 
-+ (void)clearCacheDirectory
++ (void)disableCaching
 {
     NSURLCache *sharedCache = [[NSURLCache alloc] initWithMemoryCapacity:0 diskCapacity:0 diskPath:nil];
     [NSURLCache setSharedURLCache:sharedCache];
+}
+
++ (NSCachedURLResponse *)cacheResponseForRequest:(NSURLRequest *)request withResponseData:(NSData *)responseData
+{
+    NSParameterAssert(request);
+    NSParameterAssert(responseData);
     
-    NSError *error = nil;
-    NSString *cachePath = RKCachesDirectory();
-    BOOL success = [[NSFileManager defaultManager] removeItemAtPath:cachePath error:&error];
-    if (success) {
-        RKLogDebug(@"Cleared cache directory...");
-        success = [[NSFileManager defaultManager] createDirectoryAtPath:cachePath withIntermediateDirectories:YES attributes:nil error:&error];
-        if (!success) {
-            RKLogError(@"Failed creation of cache path '%@': %@", cachePath, [error localizedDescription]);
-        }
-    } else {
-        RKLogError(@"Failed to clear cache path '%@': %@", cachePath, [error localizedDescription]);
-    }
+    NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:[request URL] statusCode:200 HTTPVersion:@"1.1" headerFields:nil];
+    NSAssert(response, @"Failed to build cached response");
+    NSCachedURLResponse *cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:response data:responseData];
+    [[NSURLCache sharedURLCache] storeCachedResponse:cachedResponse forRequest:request];
+    
+    // Verify that we can get the cached response back
+    NSCachedURLResponse *storedResponse = [[NSURLCache sharedURLCache] cachedResponseForRequest:request];
+    NSAssert(storedResponse, @"Expected to retrieve cached response for request '%@', instead got nil.", request);
+    
+    return cachedResponse;
+}
+
++ (NSCachedURLResponse *)cacheResponseForURL:(NSURL *)URL HTTPMethod:(NSString *)HTTPMethod headers:(NSDictionary *)requestHeaders withData:(NSData *)responseData
+{
+    NSParameterAssert(URL);
+    NSParameterAssert(HTTPMethod);
+    NSParameterAssert(responseData);
+    
+    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
+    request.HTTPMethod = HTTPMethod;
+    [request setAllHTTPHeaderFields:requestHeaders];
+    return [self cacheResponseForRequest:request withResponseData:responseData];
 }
 
 @end