Merge pull request #1064 from terrestris/add-array-util

Add array util

src/ArrayUtil/ArrayUtil.spec.ts

@@ -0,0 +1,17 @@
+import { joinArrayWith } from './ArrayUtil';
+
+describe('ArrayUtil', () => {
+
+  it('is defined', () => {
+    expect(joinArrayWith).not.toBe(undefined);
+  });
+
+  it('works as expected', () => {
+    expect(joinArrayWith([1, 2, 3], 'a')).toStrictEqual([1, 'a', 2, 'a', 3]);
+  });
+
+  it('works with an empty array', () => {
+    expect(joinArrayWith([], 'a')).toStrictEqual([]);
+  });
+
+});

src/ArrayUtil/ArrayUtil.ts

@@ -0,0 +1,20 @@
+/**
+ * Works like the standard .join, except it returns a new array with the value inserted between all values of the array
+ * instead of a string.
+ *
+ * @param list any array
+ * @param value any value
+ * @returns the new array
+ */
+export const joinArrayWith = (list: any[], value: any) => {
+  const newList: any[] = [];
+  list.forEach((item, idx) => {
+    if (idx === 0) {
+      newList.push(item);
+    } else {
+      newList.push(value);
+      newList.push(item);
+    }
+  });
+  return newList;
+};