[ios, macos] handle duplicate layer error

2 files changed, 58 insertions, 7 deletions

diff --git a/platform/darwin/src/MGLStyle.mm b/platform/darwin/src/MGLStyle.mm
index 6116f4df28..7d7ca73a58 100644
--- a/platform/darwin/src/MGLStyle.mm
+++ b/platform/darwin/src/MGLStyle.mm
@@ -271,10 +271,18 @@ static NSURL *MGLStyleURL_emerald;
         [NSException raise:NSRangeException
                     format:@"Cannot insert style layer at out-of-bounds index %lu.", (unsigned long)index];
     } else if (index == 0) {
-        [styleLayer addToMapView:self.mapView];
+        try {
+            [styleLayer addToMapView:self.mapView];
+        } catch (const std::runtime_error & err) {
+            [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
+        }
     } else {
-        MGLStyleLayer *sibling = [self layerFromMBGLLayer:layers.at(layers.size() - index)];
-        [styleLayer addToMapView:self.mapView belowLayer:sibling];
+        try {
+            MGLStyleLayer *sibling = [self layerFromMBGLLayer:layers.at(layers.size() - index)];
+            [styleLayer addToMapView:self.mapView belowLayer:sibling];
+        } catch (std::runtime_error & err) {
+            [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
+        }
     }
 }
 
@@ -350,7 +358,11 @@ static NSURL *MGLStyleURL_emerald;
          layer];
     }
     [self willChangeValueForKey:@"layers"];
-    [layer addToMapView:self.mapView];
+    try {
+        [layer addToMapView:self.mapView];
+    } catch (std::runtime_error & err) {
+        [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
+    }
     [self didChangeValueForKey:@"layers"];
 }
 
@@ -375,7 +387,11 @@ static NSURL *MGLStyleURL_emerald;
          sibling];
     }
     [self willChangeValueForKey:@"layers"];
-    [layer addToMapView:self.mapView belowLayer:sibling];
+    try {
+        [layer addToMapView:self.mapView belowLayer:sibling];
+    } catch (std::runtime_error & err) {
+        [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
+    }
     [self didChangeValueForKey:@"layers"];
 }
 
@@ -413,10 +429,18 @@ static NSURL *MGLStyleURL_emerald;
          @"Make sure sibling was obtained using -[MGLStyle layerWithIdentifier:].",
          sibling];
     } else if (index + 1 == layers.size()) {
-        [layer addToMapView:self.mapView];
+        try {
+            [layer addToMapView:self.mapView];
+        } catch (std::runtime_error & err) {
+            [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
+        }
     } else {
         MGLStyleLayer *sibling = [self layerFromMBGLLayer:layers.at(index + 1)];
-        [layer addToMapView:self.mapView belowLayer:sibling];
+        try {
+            [layer addToMapView:self.mapView belowLayer:sibling];
+        } catch (std::runtime_error & err) {
+            [NSException raise:@"MGLRedundantLayerIdentifierException" format:@"%s", err.what()];
+        }
     }
     [self didChangeValueForKey:@"layers"];
 }
diff --git a/platform/darwin/test/MGLStyleTests.mm b/platform/darwin/test/MGLStyleTests.mm
index 4c0c163b38..5231d2dcf4 100644
--- a/platform/darwin/test/MGLStyleTests.mm
+++ b/platform/darwin/test/MGLStyleTests.mm
@@ -1,5 +1,8 @@
 #import "MGLMapView.h"
 #import "MGLStyle_Private.h"
+#if TARGET_OS_IPHONE
+#import "MGLMapView+MGLCustomStyleLayerAdditions.h"
+#endif
 
 #import "MGLGeoJSONSource.h"
 #import "MGLRasterSource.h"
@@ -165,6 +168,30 @@
     XCTAssertThrowsSpecificNamed([self.style addLayer:symbolLayer], NSException, @"MGLRedundantLayerException");
 }
 
+- (void)testAddingLayersWithDuplicateIdentifiers {
+    //Just some source
+    MGLVectorSource *source = [[MGLVectorSource alloc] initWithIdentifier:@"my-source" URL:[NSURL URLWithString:@"mapbox://mapbox.mapbox-terrain-v2"]];
+    [self.mapView.style addSource: source];
+    
+    //Add initial layer
+    MGLFillStyleLayer *initial = [[MGLFillStyleLayer alloc] initWithIdentifier:@"my-layer" source:source];
+    [self.mapView.style addLayer:initial];
+    
+    //Try to add the duplicate
+    XCTAssertThrowsSpecificNamed([self.mapView.style addLayer:[[MGLFillStyleLayer alloc] initWithIdentifier:@"my-layer" source:source]], NSException, @"MGLRedundantLayerIdentifierException");
+    XCTAssertThrowsSpecificNamed([self.mapView.style insertLayer:[[MGLFillStyleLayer alloc] initWithIdentifier:@"my-layer" source:source] belowLayer:initial],NSException, @"MGLRedundantLayerIdentifierException");
+    XCTAssertThrowsSpecificNamed([self.mapView.style insertLayer:[[MGLFillStyleLayer alloc] initWithIdentifier:@"my-layer" source:source] aboveLayer:initial], NSException, @"MGLRedundantLayerIdentifierException");
+    XCTAssertThrowsSpecificNamed([self.mapView.style insertLayer:[[MGLFillStyleLayer alloc] initWithIdentifier:@"my-layer" source:source] atIndex:0], NSException, @"MGLRedundantLayerIdentifierException");
+
+#if TARGET_OS_IPHONE
+    //Try to insert a duplicate custom layer
+    MGLCustomStyleLayerDrawingHandler drawingHandler = ^(CGSize size, CLLocationCoordinate2D centerCoordinate, double zoomLevel, CLLocationDirection direction, CGFloat pitch, CGFloat perspectiveSkew) {
+    };
+    
+    XCTAssertThrowsSpecific([self.mapView insertCustomStyleLayerWithIdentifier:@"my-layer" preparationHandler:^{} drawingHandler:drawingHandler completionHandler: ^{} belowStyleLayerWithIdentifier:nil], NSException);
+#endif
+}
+
 - (NSString *)stringWithContentsOfStyleHeader {
     NSURL *styleHeaderURL = [[[NSBundle mgl_frameworkBundle].bundleURL
                               URLByAppendingPathComponent:@"Headers" isDirectory:YES]