feat: add array chunk algorithm

Data-Structures/Array/Chunk.js

@@ -0,0 +1,26 @@
+/**
+ * @function chunk
+ * @description Splits an array into smaller arrays of a specified size.
+ *   The last chunk may be smaller if the array doesn't divide evenly.
+ * @param {Array} arr - The input array to chunk
+ * @param {number} size - The size of each chunk
+ * @returns {Array} - An array of chunks
+ * @see https://en.wikipedia.org/wiki/Chunking_(computing)
+ * @example chunk([1, 2, 3, 4, 5], 2) => [[1, 2], [3, 4], [5]]
+ * @example chunk([1, 2, 3], 3) => [[1, 2, 3]]
+ */
+const chunk = (arr, size) => {
+  if (!Array.isArray(arr)) {
+    throw new TypeError('First argument must be an array')
+  }
+  if (!Number.isInteger(size) || size < 1) {
+    throw new TypeError('Size must be a positive integer')
+  }
+  const result = []
+  for (let i = 0; i < arr.length; i += size) {
+    result.push(arr.slice(i, i + size))
+  }
+  return result
+}
+
+export { chunk }

Data-Structures/Array/test/Chunk.test.js

@@ -0,0 +1,59 @@
+import { chunk } from '../Chunk.js'
+
+describe('chunk', () => {
+  test('chunk([1,2,3,4,5], 2) returns [[1,2],[3,4],[5]]', () => {
+    expect(chunk([1, 2, 3, 4, 5], 2)).toEqual([[1, 2], [3, 4], [5]])
+  })
+
+  test('chunk([1,2,3], 3) returns [[1,2,3]]', () => {
+    expect(chunk([1, 2, 3], 3)).toEqual([[1, 2, 3]])
+  })
+
+  test('chunk([1,2,3,4], 2) returns [[1,2],[3,4]]', () => {
+    expect(chunk([1, 2, 3, 4], 2)).toEqual([
+      [1, 2],
+      [3, 4]
+    ])
+  })
+
+  test('chunk with size 1 returns array of single elements', () => {
+    expect(chunk([1, 2, 3], 1)).toEqual([[1], [2], [3]])
+  })
+
+  test('chunk empty array returns empty array', () => {
+    expect(chunk([], 2)).toEqual([])
+  })
+
+  test('chunk with size larger than array returns one chunk', () => {
+    expect(chunk([1, 2, 3], 10)).toEqual([[1, 2, 3]])
+  })
+
+  test('chunk does not mutate original array', () => {
+    const arr = [1, 2, 3, 4]
+    chunk(arr, 2)
+    expect(arr).toEqual([1, 2, 3, 4])
+  })
+
+  test('chunk works with strings', () => {
+    expect(chunk(['a', 'b', 'c', 'd'], 2)).toEqual([
+      ['a', 'b'],
+      ['c', 'd']
+    ])
+  })
+
+  test('throws TypeError for non-array input', () => {
+    expect(() => chunk('123', 2)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for size 0', () => {
+    expect(() => chunk([1, 2, 3], 0)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for negative size', () => {
+    expect(() => chunk([1, 2, 3], -1)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for float size', () => {
+    expect(() => chunk([1, 2, 3], 1.5)).toThrow(TypeError)
+  })
+})