apply Leaflet#984

Author: jacobweberbowery

build/rollup-config.js

@@ -1,6 +1,7 @@
 
 // Config file for running Rollup in "normal" mode (non-watch)
 
+import inject from '@rollup/plugin-inject';
 import rollupGitVersion from 'rollup-plugin-git-version'
 import json from 'rollup-plugin-json'
 
@@ -36,8 +37,17 @@ export default {
 		legacy: true, // Needed to create files loadable by IE8
 		name: 'Leaflet.markercluster',
 		sourcemap: true,
+		globals: {
+			"leaflet": "L"
+		}
 	},
+	external: [
+		"leaflet"
+	],
 	plugins: [
 		release ? json() : rollupGitVersion(),
+		inject({
+			L: "leaflet"
+		})
 	],
 };

package-lock.json

@@ -19,7 +19,8 @@
 		"leaflet": "^1.3.1",
 		"mocha": "6.0.2",
 		"phantomjs-prebuilt": "^2.1.14",
-		"rollup": "1.3.2",
+		"rollup": "1.29.1",
+		"@rollup/plugin-inject": "^4.0.0",
 		"rollup-plugin-git-version": "0.2.1",
 		"rollup-plugin-json": "3.1.0",
 		"uglify-js": "3.4.9"