Merge b8c61d1 into fe18316

iePolyfills.js

@@ -0,0 +1,64 @@
+/* eslint-disable no-bitwise, no-extend-native, prefer-rest-params */
+
+module.exports = function iePolyfills() {
+  // IE Polyfill for Array.prototype.fill
+  if (!Array.prototype.fill) {
+    Object.defineProperty(Array.prototype, 'fill', {
+      value(value) {
+        // Steps 1-2.
+        if (this == null) {
+          throw new TypeError('this is null or not defined');
+        }
+
+        const O = Object(this);
+
+        // Steps 3-5.
+        const len = O.length >>> 0;
+
+        // Steps 6-7.
+        const start = arguments[1];
+        const relativeStart = start >> 0;
+
+        // Step 8.
+        let k = relativeStart < 0
+          ? Math.max(len + relativeStart, 0)
+          : Math.min(relativeStart, len);
+
+        // Steps 9-10.
+        const end = arguments[2];
+        const relativeEnd = end === undefined
+          ? len : end >> 0;
+
+        // Step 11.
+        const final = relativeEnd < 0
+          ? Math.max(len + relativeEnd, 0)
+          : Math.min(relativeEnd, len);
+
+        // Step 12.
+        while (k < final) {
+          O[k] = value;
+          k += 1;
+        }
+
+        // Step 13.
+        return O;
+      },
+    });
+  }
+
+  // IE Polyfill for Object.entries
+  if (!Object.entries) {
+    Object.entries = function entries(obj) {
+      const ownProps = Object.keys(obj);
+      let i = ownProps.length;
+      const resArray = new Array(i); // preallocate the Array
+
+      while (i) {
+        i -= 1;
+        resArray[i] = [ownProps[i], obj[ownProps[i]]];
+      }
+
+      return resArray;
+    };
+  }
+};

index.js

@@ -1,4 +1,5 @@
-const _ = require('lodash');
+// Load polyfills for IE Array.prototype.fill and Object.entries
+require('./iePolyfills')();
 
 /**
  * Returns a comparison function used to compare entries during ranking
@@ -22,38 +23,38 @@ function getRankingFn(strategy) {
   if (strategy === 'modified-competition') {
     // Modified competition ranking ("1334" ranking)
     return (start, length) => ({
-      current: _.fill(Array(length), start + (length - 1)),
+      current: Array(length).fill(start + (length - 1)),
       next: start + length,
     });
   }
 
   if (strategy === 'dense') {
     // Dense ranking ("1223" ranking)
     return (start, length) => ({
-      current: _.fill(Array(length), start),
+      current: Array(length).fill(start),
       next: start + 1,
     });
   }
 
   if (strategy === 'ordinal') {
     // Ordinal ranking ("1234" ranking)
     return (start, length) => ({
-      current: _.range(start, start + length),
+      current: Array(length).fill(null).map((_, i) => start + i),
       next: start + length,
     });
   }
 
   if (strategy === 'fractional') {
     // Fractional ranking ("1 2.5 2.5 4" ranking)
     return (start, length) => ({
-      current: _.fill(Array(length), start + ((length - 1) / 2)),
+      current: Array(length).fill(start + ((length - 1) / 2)),
       next: start + length,
     });
   }
 
   // Standard competition ranking ("1224" ranking)
   return (start, length) => ({
-    current: _.fill(Array(length), start),
+    current: Array(length).fill(start),
     next: start + length,
   });
 }
@@ -88,15 +89,15 @@ module.exports = {
 
     items.forEach((e) => {
       const score = scoreFn(e);
-      if (_.has(buckets, score)) {
+      if (buckets[score]) {
         buckets[score].push(e);
       } else {
         buckets[score] = [e];
       }
     });
 
     // convert to array for sorting
-    buckets = _.toPairs(buckets);
+    buckets = Object.entries(buckets);
 
     // sort based on the score
     buckets.sort(compareFn);