Adds an integration test harness to the iOS project

This will allow us to write lightweight integration tests between MGLMapView and the core renderer.
Also includes a test for the recent custom layer memory fix, reverting the fix in order to demonstrate the failing test.

3 files changed, 14 insertions, 2 deletions

diff --git a/platform/darwin/src/MGLOpenGLStyleLayer.mm b/platform/darwin/src/MGLOpenGLStyleLayer.mm
index 8933a77382..2bc76c9912 100644
--- a/platform/darwin/src/MGLOpenGLStyleLayer.mm
+++ b/platform/darwin/src/MGLOpenGLStyleLayer.mm
@@ -47,7 +47,8 @@ void MGLDrawCustomStyleLayer(void *context, const mbgl::style::CustomLayerRender
     when creating an OpenGL style layer.
  */
 void MGLFinishCustomStyleLayer(void *context) {
-    MGLOpenGLStyleLayer *layer = (__bridge_transfer MGLOpenGLStyleLayer *)context;
+    //TODO: AK: revert once failing test established
+    MGLOpenGLStyleLayer *layer = (__bridge MGLOpenGLStyleLayer *)context;
     [layer willMoveFromMapView:layer.style.mapView];
 }
 
@@ -101,7 +102,8 @@ void MGLFinishCustomStyleLayer(void *context) {
                                                             MGLPrepareCustomStyleLayer,
                                                             MGLDrawCustomStyleLayer,
                                                             MGLFinishCustomStyleLayer,
-                                                            (__bridge_retained void *)self);
+                              //TODO: AK: revert once failing test established
+                                                            (__bridge void *)self);
     return self = [super initWithPendingLayer:std::move(layer)];
 }
 
@@ -116,7 +118,10 @@ void MGLFinishCustomStyleLayer(void *context) {
         [NSException raise:@"MGLLayerReuseException"
                     format:@"%@ cannot be added to more than one MGLStyle at a time.", self];
     }
+    //TODO: AK: remove once failing test established
+    _style.openGLLayers[self.identifier] = nil;
     _style = style;
+    _style.openGLLayers[self.identifier] = self;
 }
 
 - (void)addToStyle:(MGLStyle *)style belowLayer:(MGLStyleLayer *)otherLayer {
diff --git a/platform/darwin/src/MGLStyle.mm b/platform/darwin/src/MGLStyle.mm
index 5221e838f8..50d8abf72b 100644
--- a/platform/darwin/src/MGLStyle.mm
+++ b/platform/darwin/src/MGLStyle.mm
@@ -77,6 +77,8 @@
 @property (nonatomic, readonly, weak) MGLMapView *mapView;
 @property (nonatomic, readonly) mbgl::style::Style *rawStyle;
 @property (readonly, copy, nullable) NSURL *URL;
+//TODO: AK: remove once failing test established
+@property (nonatomic, readwrite, strong) NS_MUTABLE_DICTIONARY_OF(NSString *, MGLOpenGLStyleLayer *) *openGLLayers;
 @property (nonatomic) NS_MUTABLE_DICTIONARY_OF(NSString *, NS_DICTIONARY_OF(NSObject *, MGLTextLanguage *) *) *localizedLayersByIdentifier;
 
 @end
@@ -168,6 +170,8 @@ static NSURL *MGLStyleURL_trafficNight;
     if (self = [super init]) {
         _mapView = mapView;
         _rawStyle = rawStyle;
+        //TODO: AK: remove once failing test established
+        _openGLLayers = [NSMutableDictionary dictionary];
         _localizedLayersByIdentifier = [NSMutableDictionary dictionary];
     }
     return self;
diff --git a/platform/darwin/src/MGLStyle_Private.h b/platform/darwin/src/MGLStyle_Private.h
index 4cbe953a44..16035241f8 100644
--- a/platform/darwin/src/MGLStyle_Private.h
+++ b/platform/darwin/src/MGLStyle_Private.h
@@ -26,6 +26,9 @@ namespace mbgl {
 
 - (nullable NS_ARRAY_OF(MGLAttributionInfo *) *)attributionInfosWithFontSize:(CGFloat)fontSize linkColor:(nullable MGLColor *)linkColor;
 
+//TODO: AK: remove once failing test established
+@property (nonatomic, readonly, strong) NS_MUTABLE_DICTIONARY_OF(NSString *, MGLOpenGLStyleLayer *) *openGLLayers;
+
 - (void)setStyleClasses:(NS_ARRAY_OF(NSString *) *)appliedClasses transitionDuration:(NSTimeInterval)transitionDuration;
 
 @end