Improve the readability of tomorrow.js (solved #775)

snippets/tomorrow.md

@@ -2,20 +2,18 @@
 
 Results in a string representation of tomorrow's date.
 
-Use `new Date()` to get today's date, adding one day using `Date.getDate()` and `Date.setDate()`, and converting the Date object to a string.
+First we use `new Date()` to get today's date, then add one day using `Date.getDate()` and mutate the initial `Date` via `Date.setDate()`. The we use `.toISOString` to get the date part of the string – discarding the time part.
 
 ```js
-const tomorrow = (long = false) => {
+const tomorrow = () => {
   let t = new Date();
   t.setDate(t.getDate() + 1);
-  const ret = `${t.getFullYear()}-${String(t.getMonth() + 1).padStart(2, '0')}-${String(
-    t.getDate()
-  ).padStart(2, '0')}`;
-  return !long ? ret : `${ret}T00:00:00`;
+  return t.toISOString().split('T')[0];
 };
 ```
 
 ```js
-tomorrow(); // 2017-12-27 (if current date is 2017-12-26)
-tomorrow(true); // 2017-12-27T00:00:00 (if current date is 2017-12-26)
+tomorrow(); // 2018-10-18 (if current date is 2018-10-18)
+// if you need the time to indicate the start of the day as well:
+`${tomorrow()}T00:00:00}: // 2018-10-18T00:00:00
 ```

test/tomorrow/tomorrow.js

@@ -1,9 +1,7 @@
-const tomorrow = (long = false) => {
+const tomorrow = () => {
   let t = new Date();
   t.setDate(t.getDate() + 1);
-  const ret = `${t.getFullYear()}-${String(t.getMonth() + 1).padStart(2, '0')}-${String(
-    t.getDate()
-  ).padStart(2, '0')}`;
-  return !long ? ret : `${ret}T00:00:00`;
+  return t.toISOString().split('T')[0];
 };
+
 module.exports = tomorrow;

test/tomorrow/tomorrow.test.js

@@ -4,6 +4,10 @@ const tomorrow = require('./tomorrow.js');
 test('tomorrow is a Function', () => {
   expect(tomorrow).toBeInstanceOf(Function);
 });
+test('Returns the correct type', () => {
+  expect(typeof tomorrow()).toBe('string');
+});
+
 const t1 = new Date(new Date().getFullYear(), new Date().getMonth(), new Date().getDate() + 1);
 const t2 = new Date(tomorrow());
 test('Returns the correct year', () => {