Merge pull request webpack#7407 from prplx/master

Refactor JsonpMainTemplatePlugin

Author: sokra

lib/web/JsonpMainTemplatePlugin.js

@@ -32,28 +32,17 @@ class JsonpMainTemplatePlugin {
 			const allPrefetchChunks = chunk.getChildIdsByOrdersMap(true).prefetch;
 			return allPrefetchChunks && Object.keys(allPrefetchChunks).length;
 		};
-		// TODO refactor this
-		if (!mainTemplate.hooks.jsonpScript) {
-			mainTemplate.hooks.jsonpScript = new SyncWaterfallHook([
-				"source",
-				"chunk",
-				"hash"
-			]);
-		}
-		if (!mainTemplate.hooks.linkPreload) {
-			mainTemplate.hooks.linkPreload = new SyncWaterfallHook([
-				"source",
-				"chunk",
-				"hash"
-			]);
-		}
-		if (!mainTemplate.hooks.linkPrefetch) {
-			mainTemplate.hooks.linkPrefetch = new SyncWaterfallHook([
-				"source",
-				"chunk",
-				"hash"
-			]);
-		}
+
+		// TODO webpack 5, no adding to .hooks, use WeakMap and static methods
+		["jsonpScript", "linkPreload", "linkPrefetch"].forEach(hook => {
+			if (!mainTemplate.hooks[hook]) {
+				mainTemplate.hooks[hook] = new SyncWaterfallHook([
+					"source",
+					"chunk",
+					"hash"
+				]);
+			}
+		});
 
 		const getScriptSrcPath = (hash, chunk, chunkIdExpression) => {
 			const chunkFilename = mainTemplate.outputOptions.chunkFilename;