Adding chunked to array

src/arrays/chunked.test.ts

@@ -0,0 +1,44 @@
+import chunked from './chunked';
+
+describe('chunked', () => {
+  it.each([
+    { input: [1], size: 0 },
+    { input: [1, 2], size: 3 },
+  ])('chunks default', ({ input, size }) => {
+    const result = chunked(input, size);
+
+    expect(result).toEqual([input]);
+  });
+
+  it.each([{ size: 0 }, { size: -1 }])('chunks empty input', ({ size }) => {
+    const result = chunked([], size);
+
+    expect(result).toEqual([]);
+  });
+
+  it.each([{ size: -3 }, { size: 0 }])(
+    'chunks zero or bellow size',
+    ({ size }) => {
+      const input = [1, 2, 3, 4];
+
+      const result = chunked(input, size);
+
+      expect(result).toEqual([input]);
+    }
+  );
+
+  it('chunks in to equal pieces', () => {
+    const result = chunked([1, 2, 3, 4], 2);
+
+    expect(result).toEqual([
+      [1, 2],
+      [3, 4],
+    ]);
+  });
+
+  it('chunks in to uneven pieces', () => {
+    const result = chunked([1, 2, 3, 4], 3);
+
+    expect(result).toEqual([[1, 2, 3], [4]]);
+  });
+});

src/arrays/chunked.ts

@@ -0,0 +1,22 @@
+export function chunked<Element>(
+  array: Element[],
+  chunkSize: number
+): Element[][] {
+  let buffer: Element[] = [];
+  const chunks: Element[][] = [];
+  array.forEach((item, index) => {
+    buffer.push(item);
+    if (index % chunkSize !== chunkSize - 1) return;
+
+    chunks.push(buffer);
+    buffer = [];
+  });
+
+  if (buffer.length > 0) {
+    chunks.push(buffer);
+  }
+
+  return chunks;
+}
+
+export default chunked;

src/arrays/index.ts

@@ -1,3 +1,4 @@
 export * from './compactMap';
 export * from './uniques';
 export * from './zip';
+export * from './chunked';