allow ie in find

Author: Barthélémy Ledoux

demo/App.vue

@@ -71,6 +71,7 @@ export default {
   }
 };
 </script>
+
 <style>
 body {
   font-family: "Roboto Mono", monospace;

demo/find.polyfill.js

@@ -0,0 +1,46 @@
+// https://tc39.github.io/ecma262/#sec-array.prototype.find
+if (!Array.prototype.find) {
+  Object.defineProperty(Array.prototype, "find", {
+    value: function(predicate) {
+      // 1. Let O be ? ToObject(this value).
+      if (this == null) {
+        throw TypeError('"this" is null or not defined');
+      }
+
+      var o = Object(this);
+
+      // 2. Let len be ? ToLength(? Get(O, "length")).
+      var len = o.length >>> 0;
+
+      // 3. If IsCallable(predicate) is false, throw a TypeError exception.
+      if (typeof predicate !== "function") {
+        throw TypeError("predicate must be a function");
+      }
+
+      // 4. If thisArg was supplied, let T be thisArg; else let T be undefined.
+      var thisArg = arguments[1];
+
+      // 5. Let k be 0.
+      var k = 0;
+
+      // 6. Repeat, while k < len
+      while (k < len) {
+        // a. Let Pk be ! ToString(k).
+        // b. Let kValue be ? Get(O, Pk).
+        // c. Let testResult be ToBoolean(? Call(predicate, T, « kValue, k, O »)).
+        // d. If testResult is true, return kValue.
+        var kValue = o[k];
+        if (predicate.call(thisArg, kValue, k, o)) {
+          return kValue;
+        }
+        // e. Increase k by 1.
+        k++;
+      }
+
+      // 7. Return undefined.
+      return undefined;
+    },
+    configurable: true,
+    writable: true
+  });
+}

demo/main.js

@@ -1,8 +1,9 @@
-import Vue from 'vue'
-import App from './App.vue'
+import "./find.polyfill";
+import Vue from "vue";
+import App from "./App.vue";
 
-Vue.config.productionTip = false
+Vue.config.productionTip = false;
 
 new Vue({
-  render: h => h(App),
-}).$mount('#app')
+  render: h => h(App)
+}).$mount("#app");