Use errors instead of exceptions when creating a PFFile.

Switching to errors provides a more consistent interface, as we should never use exceptions in objective-c except for unrecoverable errors.

Fixes #338.

Author: richardjrossiii

Parse/PFFile.h

@@ -35,7 +35,7 @@ PF_ASSUME_NONNULL_BEGIN
 
  @returns A new `PFFile`.
  */
-+ (instancetype)fileWithData:(NSData *)data;
++ (PF_NULLABLE instancetype)fileWithData:(NSData *)data;
 
 /*!
  @abstract Creates a file with given data and name.
@@ -47,7 +47,7 @@ PF_ASSUME_NONNULL_BEGIN
 
  @returns A new `PFFile` object.
  */
-+ (instancetype)fileWithName:(PF_NULLABLE NSString *)name data:(NSData *)data;
++ (PF_NULLABLE instancetype)fileWithName:(PF_NULLABLE NSString *)name data:(NSData *)data;
 
 /*!
  @abstract Creates a file with the contents of another file.
@@ -61,7 +61,8 @@ PF_ASSUME_NONNULL_BEGIN
 
  @returns A new `PFFile` instance.
  */
-+ (instancetype)fileWithName:(PF_NULLABLE NSString *)name contentsAtPath:(NSString *)path;
++ (PF_NULLABLE instancetype)fileWithName:(PF_NULLABLE NSString *)name
+                          contentsAtPath:(NSString *)path PF_SWIFT_UNAVAILABLE;
 
 /*!
  @abstract Creates a file with the contents of another file.
@@ -75,7 +76,9 @@ PF_ASSUME_NONNULL_BEGIN
 
  @returns A new `PFFile` instance or `nil` if the error occured.
  */
-+ (instancetype)fileWithName:(PF_NULLABLE NSString *)name contentsAtPath:(NSString *)path error:(NSError **)error;
++ (PF_NULLABLE instancetype)fileWithName:(PF_NULLABLE NSString *)name
+                          contentsAtPath:(NSString *)path
+                                   error:(NSError **)error;
 
 /*!
  @abstract Creates a file with given data, name and content type.
@@ -89,9 +92,9 @@ PF_ASSUME_NONNULL_BEGIN
 
  @returns A new `PFFile` instance.
  */
-+ (instancetype)fileWithName:(PF_NULLABLE NSString *)name
-                        data:(NSData *)data
-                 contentType:(PF_NULLABLE NSString *)contentType;
++ (PF_NULLABLE instancetype)fileWithName:(PF_NULLABLE NSString *)name
+                                    data:(NSData *)data
+                             contentType:(PF_NULLABLE NSString *)contentType PF_SWIFT_UNAVAILABLE;
 
 /*!
  @abstract Creates a file with given data, name and content type.
@@ -106,10 +109,10 @@ PF_ASSUME_NONNULL_BEGIN
 
  @returns A new `PFFile` instance or `nil` if the error occured.
  */
-+ (instancetype)fileWithName:(PF_NULLABLE NSString *)name
-                        data:(NSData *)data
-                 contentType:(PF_NULLABLE NSString *)contentType
-                       error:(NSError **)error;
++ (PF_NULLABLE instancetype)fileWithName:(PF_NULLABLE NSString *)name
+                                    data:(NSData *)data
+                             contentType:(PF_NULLABLE NSString *)contentType
+                                   error:(NSError **)error;
 
 /*!
  @abstract Creates a file with given data and content type.

Parse/PFFile.m

@@ -17,6 +17,7 @@
 #import "PFAsyncTaskQueue.h"
 #import "PFCommandResult.h"
 #import "PFCoreManager.h"
+#import "PFErrorUtilities.h"
 #import "PFFileController.h"
 #import "PFFileManager.h"
 #import "PFFileStagingController.h"
@@ -73,12 +74,26 @@ + (instancetype)fileWithName:(NSString *)name contentsAtPath:(NSString *)path {
 + (instancetype)fileWithName:(NSString *)name contentsAtPath:(NSString *)path error:(NSError **)error {
     NSFileManager *fileManager = [NSFileManager defaultManager];
     BOOL directory = NO;
-    PFParameterAssert([fileManager fileExistsAtPath:path isDirectory:&directory] && !directory,
-                      @"%@ is not a valid file path for a PFFile.", path);
 
-    NSDictionary *attributess = [fileManager attributesOfItemAtPath:path error:nil];
-    unsigned long long length = [attributess[NSFileSize] unsignedLongValue];
-    PFParameterAssert(length <= PFFileMaxFileSize, @"PFFile cannot be larger than %lli bytes", PFFileMaxFileSize);
+    if (![fileManager fileExistsAtPath:path isDirectory:&directory] || directory) {
+        NSString *message = [NSString stringWithFormat:@"Failed to create PFFile at path '%@': "
+                                                        "file does not exist.", path];
+        *error = [NSError errorWithDomain:NSPOSIXErrorDomain
+                                     code:ENOENT
+                                 userInfo:@{ NSLocalizedDescriptionKey: message }];
+        return nil;
+    }
+
+    NSDictionary *attributes = [fileManager attributesOfItemAtPath:path error:nil];
+    unsigned long long length = [attributes[NSFileSize] unsignedLongValue];
+    if (length > PFFileMaxFileSize) {
+        NSString *message = [NSString stringWithFormat:@"Failed to create PFFile at path '%@': "
+                                                        "file is larger than %lluMB.", path, (PFFileMaxFileSize >> 20)];
+        *error = [NSError errorWithDomain:NSPOSIXErrorDomain
+                                     code:EFBIG
+                                 userInfo:@{ NSLocalizedDescriptionKey: message }];
+        return nil;
+    }
 
     PFFile *file = [self fileWithName:name url:nil];
     if (![file _stageWithPath:path error:error]) {
@@ -100,8 +115,22 @@ + (instancetype)fileWithName:(NSString *)name
                         data:(NSData *)data
                  contentType:(NSString *)contentType
                        error:(NSError **)error {
-    PFParameterAssert([data length] <= PFFileMaxFileSize,
-                      @"PFFile cannot be larger than %llu bytes", PFFileMaxFileSize);
+    if (!data) {
+        NSString *message = @"Cannot create a PFFile with nil data.";
+        *error = [NSError errorWithDomain:NSPOSIXErrorDomain
+                                     code:EINVAL
+                                 userInfo:@{ NSLocalizedDescriptionKey: message }];
+        return nil;
+    }
+
+    if ([data length] > PFFileMaxFileSize) {
+        NSString *message = [NSString stringWithFormat:@"Failed to create PFFile with data: "
+                                                        "data is larger than %lluMB.", (PFFileMaxFileSize >> 20)];
+        *error = [NSError errorWithDomain:NSPOSIXErrorDomain
+                                     code:EFBIG
+                                 userInfo:@{ NSLocalizedDescriptionKey: message }];
+        return nil;
+    }
 
     PFFile *file = [[self alloc] initWithName:name urlString:nil mimeType:contentType];
     if (![file _stageWithData:data error:error]) {

Tests/Unit/FileUnitTests.m

@@ -193,7 +193,16 @@ - (void)testContructors {
 
 - (void)testConstructorWithTooLargeData {
     NSMutableData *data = [NSMutableData dataWithLength:(10 * 1048576 + 1)];
-    PFAssertThrowsInvalidArgumentException([PFFile fileWithData:data]);
+
+    NSError *error = nil;
+    PFFile *file = [PFFile fileWithName:@"testFile"
+                                   data:data
+                            contentType:nil
+                                  error:&error];
+
+    XCTAssertNil(file);
+    XCTAssertEqualObjects(PFParseErrorDomain, error.domain);
+    XCTAssertEqual(EFBIG, error.code);
 }
 
 - (void)testUploading {