Use lodash throttle

extensions/markdown/package.json

@@ -283,12 +283,14 @@
 	},
 	"devDependencies": {
 		"@types/highlight.js": "9.1.10",
+		"@types/lodash.throttle": "^4.1.3",
 		"@types/markdown-it": "0.0.2",
 		"@types/node": "7.0.43",
+		"lodash.throttle": "^4.1.1",
 		"ts-loader": "^4.0.1",
 		"typescript": "^2.7.2",
 		"vscode": "^1.1.10",
 		"webpack": "^4.1.0",
 		"webpack-cli": "^2.0.10"
 	}
-}
+}
\ No newline at end of file

extensions/markdown/preview-src/index.ts

@@ -8,30 +8,7 @@ import { postCommand, postMessage } from './messaging';
 import { onceDocumentLoaded } from './events';
 import { getEditorLineNumberForPageOffset, scrollToRevealSourceLine } from './scroll-sync';
 import { ActiveLineMarker } from './activeLineMarker';
-
-// From https://remysharp.com/2010/07/21/throttling-function-calls
-function throttle(fn: (x: any) => any, threshhold: any, scope?: any) {
-	threshhold = threshhold || (threshhold = 250);
-	var last: any, deferTimer: any;
-	return function (this: any, ...x: any[]) {
-		var context = scope || this;
-
-		var now = +new Date,
-			args = arguments;
-		if (last && now < last + threshhold) {
-			// hold on to it
-			clearTimeout(deferTimer);
-			deferTimer = setTimeout(function () {
-				last = now;
-				fn.apply(context, args);
-			}, threshhold + last - now);
-		} else {
-			last = now;
-			fn.apply(context, args);
-		}
-	};
-}
-
+import throttle = require('lodash.throttle');
 
 var scrollDisabled = true;
 const marker = new ActiveLineMarker();

extensions/markdown/preview-src/tsconfig.json

 {
 	"compilerOptions": {
 		"outDir": "./dist/",
-		"module": "es6",
+		"module": "commonjs",
 		"target": "es6",
 		"jsx": "react",
 		"sourceMap": true,

extensions/markdown/yarn.lock

@@ -10,6 +10,16 @@
   version "9.1.10"
   resolved "https://registry.yarnpkg.com/@types/highlight.js/-/highlight.js-9.1.10.tgz#b621f809cd9573b80992b90cffc5788208e3069c"
 
+"@types/lodash.throttle@^4.1.3":
+  version "4.1.3"
+  resolved "https://registry.yarnpkg.com/@types/lodash.throttle/-/lodash.throttle-4.1.3.tgz#8bfa4fec519d09ebce56c815bcbff3e55c604db9"
+  dependencies:
+    "@types/lodash" "*"
+
+"@types/lodash@*":
+  version "4.14.104"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.104.tgz#53ee2357fa2e6e68379341d92eb2ecea4b11bb80"
+
 "@types/markdown-it@0.0.2":
   version "0.0.2"
   resolved "https://registry.yarnpkg.com/@types/markdown-it/-/markdown-it-0.0.2.tgz#5d9ad19e6e6508cdd2f2596df86fd0aade598660"
@@ -3277,6 +3287,10 @@ lodash.templatesettings@^3.0.0:
     lodash._reinterpolate "^3.0.0"
     lodash.escape "^3.0.0"
 
+lodash.throttle@^4.1.1:
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/lodash.throttle/-/lodash.throttle-4.1.1.tgz#c23e91b710242ac70c37f1e1cda9274cc39bf2f4"
+
 lodash@^4.11.1, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.2, lodash@^4.17.4, lodash@^4.17.5, lodash@^4.3.0:
   version "4.17.5"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.5.tgz#99a92d65c0272debe8c96b6057bc8fbfa3bed511"