Fix up deleteAttachments method since making attachmentFolder

dispatchOnce

// FREEBIE

src/Messages/Attachments/TSAttachmentStream.m

@@ -294,10 +294,28 @@ NS_ASSUME_NONNULL_BEGIN
 + (void)deleteAttachments
 {
     NSError *error;
-    [[NSFileManager defaultManager] removeItemAtPath:[self attachmentsFolder] error:&error];
+
+    NSFileManager *fileManager = [NSFileManager defaultManager];
+
+    NSURL *fileURL = [NSURL fileURLWithPath:self.attachmentsFolder];
+    NSArray<NSURL *> *contents =
+        [fileManager contentsOfDirectoryAtURL:fileURL includingPropertiesForKeys:nil options:0 error:&error];
+
     if (error) {
-        DDLogError(@"Failed to delete attachment folder with error: %@", error.debugDescription);
+        OWSFail(@"failed to get contents of attachments folder: %@ with error: %@", self.attachmentsFolder, error);
+        return;
     }
+
+    for (NSURL *url in contents) {
+        NSError *deletionError;
+        [fileManager removeItemAtURL:url error:&deletionError];
+        if (deletionError) {
+            OWSFail(@"failed to remove item at path: %@ with error: %@", filePath, deletionError);
+            // continue to try to delete remaining items.
+        }
+    }
+
+    return;
 }
 
 - (CGSize)calculateImageSize

tests/Messages/OWSDisappearingMessageFinderTest.m

@@ -1,5 +1,6 @@
-//  Created by Michael Kirk on 9/23/16.
-//  Copyright © 2016 Open Whisper Systems. All rights reserved.
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 #import "NSDate+millisecondTimeStamp.h"
 #import "OWSDisappearingMessagesFinder.h"

tests/Storage/OWSOrphanedDataCleanerTest.m

@@ -76,6 +76,9 @@
 
 - (void)testFilesWithoutInteractionsAreDeleted
 {
+    // sanity check
+    XCTAssertEqual(0, [TSAttachmentStream numberOfItemsInAttachmentsFolder]);
+
     NSError *error;
     TSAttachmentStream *attachmentStream = [[TSAttachmentStream alloc] initWithContentType:@"image/jpeg" sourceFilename:nil];
     [attachmentStream writeData:[NSData new] error:&error];
@@ -129,7 +132,6 @@
     [attachmentStream writeData:[NSData new] error:&error];
     // Intentionally not saved, because we want a lingering file.
 
-
     NSString *orphanedFilePath = [attachmentStream filePath];
     BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:orphanedFilePath];
     XCTAssert(fileExists);