Implement steps solutions - one of them with recursion, write tests

Author: somekindofwallflower

09_steps/index.js

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+// --- Directions
+// Write a function that accepts a positive number N.
+// The function should console log a step shape
+// with N levels using the # character.  Make sure the
+// step has spaces on the right hand side!
+// --- Examples
+//   steps(2)
+//       '# '
+//       '##'
+//   steps(3)
+//       '#  '
+//       '## '
+//       '###'
+//   steps(4)
+//       '#   '
+//       '##  '
+//       '### '
+//       '####'
+
+// Solution 1
+// function steps(n) {
+//     if(n === 1) {
+//         console.log("#");
+//     } else {
+//         for(let s = 1; s <= n; s++) {
+//             console.log('#'.repeat(s) + ' '.repeat(n - s))
+//
+//         }
+//     }
+// }
+
+// Solution 2
+
+// function steps(n) {
+//     for(let row = 0; row < n; row++) {
+//         let stair = "";
+//
+//         for (let column = 0; column < n; column ++) {
+//             if(column <= row) {
+//                 stair += '#';
+//             } else {
+//                 stair += ' ';
+//             }
+//         }
+//         console.log(stair);
+//     }
+// }
+
+function steps(n, row = 0, stair= '') {
+   if (n === row) {
+       return;
+   }
+   if(n === stair.length) {
+      console.log(stair);
+      return steps(n, row + 1);
+   } else {
+       if(stair.length <= row) {
+           stair += '#'
+       } else {
+           stair += ' '
+       }
+       return steps(n, row, stair);
+   }
+}
+
+module.exports = steps;

09_steps/test.js

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+const steps = require('./index');
+
+beforeEach(() => {
+    jest.spyOn(console, 'log');
+});
+
+afterEach(() => {
+    console.log.mockRestore();
+});
+
+test('steps is a function', () => {
+    expect(typeof steps).toEqual('function');
+});
+
+test('steps called with n = 1', () => {
+    steps(1);
+    expect(console.log.mock.calls[0][0]).toEqual('#');
+    expect(console.log.mock.calls.length).toEqual(1);
+});
+
+test('steps called with n = 2', () => {
+    steps(2);
+    expect(console.log.mock.calls[0][0]).toEqual('# ');
+    expect(console.log.mock.calls[1][0]).toEqual('##');
+    expect(console.log.mock.calls.length).toEqual(2);
+});
+
+test('steps called with n = 3', () => {
+    steps(3);
+    expect(console.log.mock.calls[0][0]).toEqual('#  ');
+    expect(console.log.mock.calls[1][0]).toEqual('## ');
+    expect(console.log.mock.calls[2][0]).toEqual('###');
+    expect(console.log.mock.calls.length).toEqual(3);
+});