algorithm: catalan numbers (#1149)

Dynamic-Programming/tests/CatalanNumbers.test.js

@@ -0,0 +1,14 @@
+import { catalanNumbers } from '../CatalanNumbers'
+
+describe('Testing catalanNumbers function', () => {
+  test('should return the expected array for inputs from 0 to 20', () => {
+    const expectedOutput = [
+      1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900,
+      2674440, 9694845, 35357670, 129644790, 477638700, 1767263190, 6564120420
+    ]
+
+    for (let i = 0; i <= 20; i++) {
+      expect(catalanNumbers(i)).toStrictEqual(expectedOutput.slice(0, i + 1))
+    }
+  })
+})