Prefer forward declarations for WordPressData types in ObjC headers

Just trying to understand why Keystone fails to build for testing.

Using forward declarations keeps the headers and the compilation leaner.

Author: mokagio

WordPress/Classes/Services/AccountService.h

@@ -1,15 +1,11 @@
 #import <Foundation/Foundation.h>
 #import <CoreData/CoreData.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
 @class WPAccount;
 @class RemoteUser;
+@protocol CoreDataStack;
 
 extern NSNotificationName const WPAccountEmailAndDefaultBlogUpdatedNotification;
 

WordPress/Classes/Services/BlogService.h

@@ -1,18 +1,15 @@
 #import <Foundation/Foundation.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
 extern NSString *const WordPressMinimumVersion;
 extern NSString *const WPBlogUpdatedNotification;
 extern NSString *const WPBlogSettingsUpdatedNotification;
 
+@class Blog;
 @class WPAccount;
 @class SiteInfo;
+@protocol CoreDataStack;
 
 @interface BlogService : NSObject
 

WordPress/Classes/Services/CommentService.h

@@ -1,10 +1,5 @@
 #import <Foundation/Foundation.h>
 #import <WordPressKit/WordPressKit.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -16,6 +11,7 @@ extern NSUInteger const WPTopLevelHierarchicalCommentsPerPage;
 @class BasePost;
 @class RemoteUser;
 @class CommentServiceRemoteFactory;
+@protocol CoreDataStack;
 
 @interface CommentService : NSObject
 

WordPress/Classes/Services/MediaService.h

@@ -8,8 +8,6 @@
 
 @class Media;
 @class RemoteVideoPressVideo;
-@class Blog;
-@class AbstractPost;
 @protocol ExportableAsset;
 
 extern NSErrorDomain _Nonnull const MediaServiceErrorDomain;

WordPress/Classes/Services/MenusService.h

@@ -7,11 +7,6 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-@class Blog;
-@class Menu;
-@class MenuLocation;
-@class MenuItem;
-
 typedef void(^MenusServiceSuccessBlock)(void);
 typedef void(^MenusServiceCreateOrUpdateMenuRequestSuccessBlock)(void);
 typedef void(^MenusServiceMenusRequestSuccessBlock)(NSArray<Menu *> * _Nullable menus);

WordPress/Classes/Services/PostCategoryService.h

@@ -1,14 +1,11 @@
+@import CoreData;
 #import <Foundation/Foundation.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
 @class Blog;
 @class PostCategory;
+@protocol CoreDataStack;
 
 typedef NS_ENUM(NSInteger, PostCategoryServiceErrors) {
     PostCategoryServiceErrorsBlogNotFound

WordPress/Classes/Services/PostTagService.h

@@ -6,9 +6,6 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-@class Blog;
-@class PostTag;
-
 @interface PostTagService : LocalCoreDataService
 
 /**

WordPress/Classes/Services/Reader Post/ReaderPostService.h

@@ -1,16 +1,13 @@
+@import CoreData;
 #import <Foundation/Foundation.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wnullability-completeness"
 
 @class ReaderPost;
 @class ReaderAbstractTopic;
 @class WordPressComRestApi;
+@protocol CoreDataStack;
 
 extern NSString * const ReaderPostServiceErrorDomain;
 extern NSString * const ReaderPostServiceToggleSiteFollowingState;

WordPress/Classes/Services/ReaderSiteService.h

@@ -1,9 +1,6 @@
 #import <Foundation/Foundation.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
+
+@protocol CoreDataStack;
 
 NS_ASSUME_NONNULL_BEGIN
 

WordPress/Classes/Services/ReaderTopicService.h

@@ -1,9 +1,5 @@
+@import CoreData;
 #import <Foundation/Foundation.h>
-// For some reason, and only in some files, the modular import does not work.
-// Just to be on the safe side, _all_ imports use the angle brackets style.
-// We shall try to go back to the modular style on Keystone successfully builds for testing.
-// @import WordPressData;
-#import <WordPressData/WordPressData.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -13,6 +9,7 @@ extern NSString * const ReaderTopicFreshlyPressedPathCommponent;
 @class ReaderTagTopic;
 @class ReaderSiteTopic;
 @class ReaderSearchTopic;
+@protocol CoreDataStack;
 
 @interface ReaderTopicService : NSObject