create phet-polyfill with Array.from in it. Add it to chipper preload…

…s and to scenery.js, phetsims/chipper#817

js/phet-polyfill.js

@@ -0,0 +1,93 @@
+// Copyright 2019, University of Colorado Boulder
+
+/**
+ * Preload file that contains all polyfills needed for PhET sims and supporting libraries (like scenery).
+ * @author Michael Kauzmann (PhET Interactive Simulations)
+ */
+( () => {
+  'use strict';
+
+  /* eslint-disable */
+  // Copied from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from on 11/14/2019
+  // Production steps of ECMA-262, Edition 6, 22.1.2.1
+  if ( !Array.from ) {
+    Array.from = ( function() {
+      var toStr = Object.prototype.toString;
+      var isCallable = function( fn ) {
+        return typeof fn === 'function' || toStr.call( fn ) === '[object Function]';
+      };
+      var toInteger = function( value ) {
+        var number = Number( value );
+        if ( isNaN( number ) ) { return 0; }
+        if ( number === 0 || !isFinite( number ) ) { return number; }
+        return ( number > 0 ? 1 : -1 ) * Math.floor( Math.abs( number ) );
+      };
+      var maxSafeInteger = Math.pow( 2, 53 ) - 1;
+      var toLength = function( value ) {
+        var len = toInteger( value );
+        return Math.min( Math.max( len, 0 ), maxSafeInteger );
+      };
+
+      // The length property of the from method is 1.
+      return function from( arrayLike/*, mapFn, thisArg */ ) {
+        // 1. Let C be the this value.
+        var C = this;
+
+        // 2. Let items be ToObject(arrayLike).
+        var items = Object( arrayLike );
+
+        // 3. ReturnIfAbrupt(items).
+        if ( arrayLike == null ) {
+          throw new TypeError( 'Array.from requires an array-like object - not null or undefined' );
+        }
+
+        // 4. If mapfn is undefined, then let mapping be false.
+        var mapFn = arguments.length > 1 ? arguments[ 1 ] : void undefined;
+        var T;
+        if ( typeof mapFn !== 'undefined' ) {
+          // 5. else
+          // 5. a If IsCallable(mapfn) is false, throw a TypeError exception.
+          if ( !isCallable( mapFn ) ) {
+            throw new TypeError( 'Array.from: when provided, the second argument must be a function' );
+          }
+
+          // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+          if ( arguments.length > 2 ) {
+            T = arguments[ 2 ];
+          }
+        }
+
+        // 10. Let lenValue be Get(items, "length").
+        // 11. Let len be ToLength(lenValue).
+        var len = toLength( items.length );
+
+        // 13. If IsConstructor(C) is true, then
+        // 13. a. Let A be the result of calling the [[Construct]] internal method
+        // of C with an argument list containing the single item len.
+        // 14. a. Else, Let A be ArrayCreate(len).
+        var A = isCallable( C ) ? Object( new C( len ) ) : new Array( len );
+
+        // 16. Let k be 0.
+        var k = 0;
+        // 17. Repeat, while k < len… (also steps a - h)
+        var kValue;
+        while ( k < len ) {
+          kValue = items[ k ];
+          if ( mapFn ) {
+            A[ k ] = typeof T === 'undefined' ? mapFn( kValue, k ) : mapFn.call( T, kValue, k );
+          }
+          else {
+            A[ k ] = kValue;
+          }
+          k += 1;
+        }
+        // 18. Let putStatus be Put(A, "length", len, true).
+        A.length = len;
+        // 20. Return A.
+        return A;
+      };
+    }() );
+  }
+
+  /* eslint-enable */
+} )();