Reto 3 y tests

Author: Achalogy

retos/reto-3/main.ts

@@ -0,0 +1,9 @@
+function findNaughtyStep(original, modified) {
+
+  const [lessWords, mostWords] =
+    [original, modified].sort((a, b) => a.length - b.length)
+
+  return [...mostWords].find((x, i) => [...lessWords][i] != x) ?? ""
+}
+
+module.exports = findNaughtyStep

retos/reto-3/reto3.test.js

@@ -0,0 +1,23 @@
+const findNaughtyStep = require('./main.ts')
+
+test("Test #01 - Returns a String", () => {
+  expect(
+    typeof findNaughtyStep('abcd', 'abcde')
+  ).toBe("string")
+})
+
+test("Test #02 - findNaughtyStep('abcd', 'abcde')", () => {
+  expect(findNaughtyStep('abcd', 'abcde')).toStrictEqual("e")
+})
+
+test("Test #03 - findNaughtyStep('xxxx', 'xxoxx')", () => {
+  expect(findNaughtyStep('xxxx', 'xxoxx')).toStrictEqual("o")
+})
+
+test("Test #04 - findNaughtyStep('stepfor', 'stepor')", () => {
+  expect(findNaughtyStep('stepfor', 'stepor')).toStrictEqual("f")
+})
+
+test("Test #05 - findNaughtyStep('iiiii', 'iiiii')", () => {
+  expect(findNaughtyStep('iiiii', 'iiiii')).toStrictEqual("")
+})