✨ IN PLACE

Author: UltiRequiem

minimum.ts

@@ -14,17 +14,15 @@ export function min(...numbers: number[]) {
 }
 
 export function minRecursive(...numbers: number[]) {
-  function finder(current: number, competitor?: number): number {
+  const finder = (current: number, competitor?: number): number => {
     if (!competitor) {
       return current;
-    }
-
-    if (competitor < current) {
+    } else if (competitor < current) {
       current = competitor;
     }
 
     return finder(current, numbers.pop());
-  }
+  };
 
   return finder(Infinity, numbers.pop());
 }

readme.md

@@ -8,9 +8,9 @@ I will update the test to use std/testing.ts as soon my internet is back.
 
 ## Test Driven Development
 
-I hate test driven development.
+I love test driven development.
 
-> Not really, is cool sometimes.
+> Not really
 
 The book doesn't talk about testing (Or I don't get to that part yet) but I
 implemented tests for every challenge and followed the TDD method.

reversing_array.test.ts

@@ -0,0 +1,33 @@
+import { reverseArray, reverseArrayInPlace } from "./reversing_array.ts";
+import { assert } from "./testing.ts";
+
+Deno.test("[reverseArray]", () => {
+  const exampleArray = [1, 2, 3, 4, 5];
+  const inversedArray = reverseArray(exampleArray);
+
+  // It returns a new copy
+  assert(exampleArray !== inversedArray);
+
+  const stdReversed = [...exampleArray].reverse();
+
+  assert(inversedArray.length === stdReversed.length);
+
+  for (let i = 0; i < inversedArray.length; i++) {
+    assert(inversedArray[i] === stdReversed[i]);
+  }
+});
+
+Deno.test("[reverseArrayInPlace]", () => {
+  const exampleArray = [1, 2, 3, 4, 5];
+  const expectedResult = [5, 4, 3, 2, 1];
+  const result = reverseArrayInPlace(exampleArray);
+
+  // It's same because it mutates the same array and then returns it
+  assert(exampleArray === result);
+
+  assert(exampleArray.length === result.length);
+
+  for (let i = 0; i < result.length; i++) {
+    assert(result[i] === expectedResult[i]);
+  }
+});

reversing_array.ts

@@ -0,0 +1,20 @@
+export function reverseArray<T>(array: T[]) {
+  const result = [];
+
+  for (let i = array.length - 1; i >= 0; i--) {
+    result.push(array[i]);
+  }
+
+  return result;
+}
+
+export function reverseArrayInPlace<T>(array: T[]) {
+  const { length } = array;
+  const values = [...array];
+
+  for (let i = 0; i < length; i++) {
+    array[i] = values[length - i - 1];
+  }
+
+  return array;
+}

sum.test.ts

@@ -0,0 +1,8 @@
+import { sum } from "./sum.ts";
+import { assert } from "./testing.ts";
+
+Deno.test("[sum]", () => {
+  const result = sum(1, 10, 23, 46);
+  const expectedResult = 80;
+  assert(result === expectedResult);
+});

sum.ts

@@ -0,0 +1,3 @@
+export function sum(...numbers: number[]) {
+  return numbers.reduce((previous, current) => (previous += current));
+}