From 3e3f9e89c43d4bdd10e438bb6f7a8e4e99d60aca Mon Sep 17 00:00:00 2001
From: Andrew <andrew.cherniavskii@gmail.com>
Date: Sat, 30 Sep 2017 15:58:10 +0200
Subject: [PATCH] [LayerGroup] Use `eachLayer` for iterations over layers
 (#5809)

* [LayerGroup] use eachLayer method instead of for...in

* [LayerGroup] use eachLayer method in getLayers method

* [LayerGroup] use eachLayer method in onAdd & onRemove methods

* [LayerGroup] invoke method fix

- use `eachLayer` method instead of for...in
- add unit test for `invoke` method

* revert invoke method change
---
 spec/suites/layer/LayerGroupSpec.js | 16 ++++++++++++++++
 src/layer/LayerGroup.js             | 18 ++++--------------
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/spec/suites/layer/LayerGroupSpec.js b/spec/suites/layer/LayerGroupSpec.js
index a30bbd66..3767e4b4 100644
--- a/spec/suites/layer/LayerGroupSpec.js
+++ b/spec/suites/layer/LayerGroupSpec.js
@@ -92,4 +92,20 @@
 			L.geoJson(layerGroup.toGeoJSON());
 		});
 	});
+
+	describe("#invoke", function () {
+		it('should invoke `setOpacity` method on every layer', function () {
+			var layers = [
+				L.marker([0, 0]),
+				L.marker([1, 1])
+			];
+			var lg = L.layerGroup(layers);
+			var opacity = 0.5;
+
+			expect(layers[0].options.opacity).to.not.eql(opacity);
+			lg.invoke('setOpacity', opacity);
+			expect(layers[0].options.opacity).to.eql(opacity);
+			expect(layers[1].options.opacity).to.eql(opacity);
+		});
+	});
 });
diff --git a/src/layer/LayerGroup.js b/src/layer/LayerGroup.js
index 19951606..33c5d83a 100644
--- a/src/layer/LayerGroup.js
+++ b/src/layer/LayerGroup.js
@@ -77,10 +77,7 @@ export var LayerGroup = Layer.extend({
 	// @method clearLayers(): this
 	// Removes all the layers from the group.
 	clearLayers: function () {
-		for (var i in this._layers) {
-			this.removeLayer(this._layers[i]);
-		}
-		return this;
+		return this.eachLayer(this.removeLayer, this);
 	},
 
 	// @method invoke(methodName: String, …): this
@@ -103,15 +100,11 @@ export var LayerGroup = Layer.extend({
 	},
 
 	onAdd: function (map) {
-		for (var i in this._layers) {
-			map.addLayer(this._layers[i]);
-		}
+		this.eachLayer(map.addLayer, map);
 	},
 
 	onRemove: function (map) {
-		for (var i in this._layers) {
-			map.removeLayer(this._layers[i]);
-		}
+		this.eachLayer(map.removeLayer, map);
 	},
 
 	// @method eachLayer(fn: Function, context?: Object): this
@@ -138,10 +131,7 @@ export var LayerGroup = Layer.extend({
 	// Returns an array of all the layers added to the group.
 	getLayers: function () {
 		var layers = [];
-
-		for (var i in this._layers) {
-			layers.push(this._layers[i]);
-		}
+		this.eachLayer(layers.push, layers);
 		return layers;
 	},