Update and rename orderByEnum.md to orderWith.md

snippets/orderByEnum.md

@@ -1,31 +0,0 @@
----
-title: orderByEnum
-tags: array,intermediate
----
-
-Returns a sorted array of objects ordered by a property, which has a known set of values (enum).
-The desired order is defined by the given `order` array.
-
-- Uses the `order` array's `indexOf` method to find the desired order for the respective value.
-- Uses the difference of both indices to determine the order, as any negative or positive number suffices (not just `-1` or `1`). 
-- Throws an error if the property has an unknown value.
-
-```js
-const orderByEnum = (arr, prop, order) =>
-  [...arr].sort((a, b) => {
-    const aOrderIndex = order.indexOf(a[prop]), bOrderIndex = order.indexOf(b[prop]);
-    if (aOrderIndex === -1) {
-      throw new Error(`Unexpected value ${a[prop]}`)
-    }
-    if (bOrderIndex === -1) {
-      throw new Error(`Unexpected value ${b[prop]}`)
-    }
-    return aOrderIndex - bOrderIndex;
-  });
-```
-
-```js
-const users = [{ name: 'fred', language: 'Javascript' }, { name: 'barney', language: 'TypeScript' }, { name: 'frannie', language: 'Javascript' }, { name: 'anna', language: 'Java' }]
-orderByEnum(users, 'language', ['Javascript', 'TypeScript', 'Java'])
-// [{name: "fred", language: "Javascript"}, {name: "frannie", language: "Javascript"}, {name: "barney", language: "TypeScript"}, {name: "anna", language: "Java"}]
-```

snippets/orderWith.md

@@ -0,0 +1,45 @@
+---
+title: orderWith
+tags: array,object,intermediate
+---
+
+Returns a sorted array of objects ordered by a property, based on the array of orders provided.
+
+- Use `Array.prototype.reduce()` to create an object from the `order` array with the values as keys and their original index as the value.
+- Use `Array.prototype.sort()` to sort the given array, skipping elements for which `prop` is empty or not in the `order` array.
+
+```js
+const orderWith = (arr, prop, order) => {
+  const orderValues = order.reduce((acc, v, i) => {
+    acc[v] = i;
+    return acc;
+  }, {});
+  return [...arr].sort((a, b) => {
+    if (orderValues[a[prop]] === undefined) return 1;
+    if (orderValues[b[prop]] === undefined) return -1;
+    return orderValues[a[prop]] - orderValues[b[prop]];
+  });
+};
+```
+
+```js
+const users = [
+  { name: 'fred', language: 'Javascript' },
+  { name: 'barney', language: 'TypeScript' },
+  { name: 'frannie', language: 'Javascript' },
+  { name: 'anna', language: 'Java' },
+  { name: 'jimmy' },
+  { name: 'nicky', language: 'Python' },
+];
+orderWith(users, 'language', ['Javascript', 'TypeScript', 'Java']);
+/* 
+[
+  { name: 'fred', language: 'Javascript' },
+  { name: 'frannie', language: 'Javascript' },
+  { name: 'barney', language: 'TypeScript' },
+  { name: 'anna', language: 'Java' },
+  { name: 'jimmy' },
+  { name: 'nicky', language: 'Python' }
+]
+*/
+```