[ios, macos] Make MGLMapView.style property nullable (#7664)

* [ios, macos] Made MGLMapView.style property nullable

MGLMapView’s style property is now nullable (optional in Swift). The property is set to nil while the style loads and in the event that the style has failed to load.

* [ios, macos] Switch to delegate method

* [macos] Create MGLMapView programmatically for layer tests

When MGLMapView is created via a nib, -initWithCoder: is called, causing styleURL to be set to nil, in turn causing the default Streets style to be loaded, fooling MGLStyleLayerTests into thinking one-line has been loaded. Instead, create MGLMapView programmatically, passing the intended style URL into the initializer, preventing Streets from being loaded.

1 files changed, 11 insertions, 2 deletions

diff --git a/platform/darwin/test/MGLStyleLayerTests.m b/platform/darwin/test/MGLStyleLayerTests.m
index 66bdc0df0b..e9ac0794a7 100644
--- a/platform/darwin/test/MGLStyleLayerTests.m
+++ b/platform/darwin/test/MGLStyleLayerTests.m
@@ -11,18 +11,27 @@
 - (void)setUp {
     [super setUp];
     [MGLAccountManager setAccessToken:@"pk.feedcafedeadbeefbadebede"];
+    NSURL *styleURL = [[NSBundle bundleForClass:[self class]] URLForResource:@"one-liner" withExtension:@"json"];
 #if TARGET_OS_IPHONE
     UIApplication *app = [UIApplication sharedApplication];
     UIViewController *vc = [[UIViewController alloc] init];
     app.keyWindow.rootViewController = vc;
     [vc view]; // Force load xib
-    _mapView = [[MGLMapView alloc] initWithFrame:CGRectMake(0, 0, 256, 256)];
+    _mapView = [[MGLMapView alloc] initWithFrame:CGRectMake(0, 0, 256, 256) styleURL:styleURL];
     [vc.view addSubview:_mapView];
-    _mapView.delegate = self;
 #else
     NSWindowController *windowController = [[NSWindowController alloc] initWithWindowNibName:@"MGLStyleLayerTests" owner:self];
+    NSView *contentView = windowController.window.contentView;
+    _mapView = [[MGLMapView alloc] initWithFrame:contentView.bounds styleURL:styleURL];
+    [contentView addSubview:_mapView];
     [windowController showWindow:nil];
 #endif
+    _mapView.delegate = self;
+    XCTAssertNil(_mapView.style);
+    [self keyValueObservingExpectationForObject:self.mapView keyPath:@"style" handler:^BOOL(MGLMapView * _Nonnull observedMapView, NSDictionary * _Nonnull change) {
+        return observedMapView.style != nil;
+    }];
+    [self waitForExpectationsWithTimeout:1 handler:nil];
 }
 
 - (void)tearDown {