feat(curriculum): add leap year lab (#55890)

Co-authored-by: Jessica Wilkins <67210629+jdwilkin4@users.noreply.github.com>
Co-authored-by: Sem Bauke <sem@freecodecamp.org>

client/i18n/locales/english/intro.json

@@ -1950,7 +1950,12 @@
           "In this lab, you will create different stories by assigning different words to different variables."
         ]
       },
-      "cktz": { "title": "155", "intro": [] },
+      "lab-leap-year-calculator": {
+        "title": "Build a Leap Year Calculator ",
+        "intro": [
+          "In this lab you will use conditional statements and loops to determine if a year is a leap year."
+        ]
+      },
       "pljo": { "title": "156", "intro": [] },
       "avln": { "title": "157", "intro": [] },
       "mexq": { "title": "158", "intro": [] },

client/src/pages/learn/front-end-development/lab-leap-year-calculator/index.md

@@ -0,0 +1,9 @@
+---
+title: Introduction to the  a Leap Year Calculator
+block: lab-leap-year-calculator
+superBlock: front-end-development
+---
+
+## Introduction to Leap Year Calculator
+
+In this lab you will utilize conditional statements and loops to create a leap year calculator.

curriculum/challenges/_meta/lab-leap-year-calculator/meta.json

@@ -0,0 +1,11 @@
+{
+  "name": "Build a Leap Year Calculator ",
+  "isUpcomingChange": true,
+  "usesMultifileEditor": true,
+  "blockType": "lab",
+  "dashedName": "lab-leap-year-calculator",
+  "order": 155,
+  "superBlock": "front-end-development",
+  "challengeOrder": [{ "id": "66c06fad3475cd92421b9ac2", "title": "Build a Leap Year Calculator" }],
+  "helpCategory": "JavaScript"
+}

curriculum/challenges/english/25-front-end-development/lab-leap-year-calculator/66c06fad3475cd92421b9ac2.md

@@ -0,0 +1,109 @@
+---
+id: 66c06fad3475cd92421b9ac2
+title: Build a Leap Year Calculator
+challengeType: 14
+dashedName: build-a-leap-year-calculator
+---
+
+# --description--
+
+A leap year is a year that is divisible by `4`, except for years that are divisible by `100` and not divisible by `400`. For example, `2000` is a leap year, but `1900` is not. Also, a leap year has an extra day in February, which is the 29th day of the month.
+
+**Objective:** Fulfill the user stories below and get all the tests to pass to complete the lab. 
+
+**User Stories:**
+
+1. Define a function called `isLeapYear` that takes a number as an argument.
+2. Outside the function, declare a variable `year` that stores the value of the year you want to check.
+3. Inside the funtion, use an `if/ else` statement or a ternary operator to check if the year is a leap year. 
+4. To check if the year is a leap year, fulfill the following conditions: 
+
+   - If the year is divisible by `4`, then it is a leap year.
+   - If the year is divisible by `100`, then it is not a leap year.
+   - If the year is divisible by `400`, then it is a leap year.
+
+5. If the year is a leap year, return `[year] is a leap year.`. Otherwise, return `[year] is not a leap year.`. You will replace `[year]` with the parameter defined in the `isLeapYear` function.
+6. You should call the `isLeapYear` function with `year` as the argument and assign the result to a variable named `result`.
+7. You should output the `result` variable to the console using `console.log()`.
+
+# --hints--
+
+You should define a function named `isLeapYear`.
+
+```js
+assert(typeof isLeapYear === 'function');
+```
+
+The `isLeapYear` funtion should take a number as an argument.
+
+```js
+assert.match(isLeapYear.toString(), /\s*isLeapYear\(\s*\w+\s*\)/);
+```
+
+You should declare a variable `year` and assign it a value to check if it is a leap year.
+
+```js
+assert.isDefined(year);
+```
+
+The `year` variable shouldn't be empty.
+
+```js
+assert.isNotNull(year);
+```
+
+With `2024` as the value of the `year` variable, the `result` should be `2024 is a leap year.`.
+
+```js
+assert.strictEqual(isLeapYear(2024), '2024 is a leap year.');
+```
+
+With `1900` as the value of the `year` variable, the `result` should be `1900 is not a leap year.`.
+
+```js
+assert.strictEqual(isLeapYear(1900), '1900 is not a leap year.');
+
+```
+
+You should call the `isLeapYear` function and pass `year` as a parameter.
+
+```js
+assert.match(__helpers.removeJSComments(code), /isLeapYear\(\s*year\s*\)/);
+```
+
+You should store the result of calling the `isLeapYear` function in a variable named `result`.
+
+```js
+assert.match(__helpers.removeJSComments(code), /const\s+result\s*=\s*isLeapYear\(\s*year\s*\)/);
+```
+
+You should output the `result` to the console using `console.log()`.
+
+```js
+assert.match(__helpers.removeJSComments(code), /console\.log\(\s*result\s*\)/);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```js
+
+```
+
+# --solutions--
+
+```js
+function isLeapYear(year) {
+  if ((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0) {
+    return(year + " is a leap year.");
+  } else {
+    return(year + " is not a leap year.");
+  }
+}
+
+const year = 2024;
+const result = isLeapYear(year);
+console.log(result);
+```
+