feat(curriculum): add email masker lab (#55768)

Co-authored-by: Jessica Wilkins <67210629+jdwilkin4@users.noreply.github.com>

client/i18n/locales/english/intro.json

@@ -1917,7 +1917,6 @@
       },
       "axgb": { "title": "138", "intro": [] },
       "rwac": { "title": "139", "intro": [] },
-      "uzjg": { "title": "140", "intro": [] },
       "hxwa": { "title": "141", "intro": [] },
       "xkbo": { "title": "142", "intro": [] },
       "nkxq": { "title": "143", "intro": [] },
@@ -1935,7 +1934,12 @@
           "In this workshop, you will review working with functions by building a calculator."
         ]
       },
-      "hqba": { "title": "153", "intro": [] },
+      "lab-email-masker": {
+        "title": "Build an Email Masker",
+        "intro": [
+          "In this lab, you'll build an email masker that will take an email address and obscure it."
+        ]
+      },
       "lab-sentence-maker": {
         "title": "Build a Sentence Maker",
         "intro": [

client/src/pages/learn/front-end-development/lab-email-masker/index.md

@@ -0,0 +1,9 @@
+---
+title: Introduction to the Build an Email Masker
+block: lab-email-masker
+superBlock: front-end-development
+---
+
+## Introduction to the Build an Email Masker
+
+In this lab, you'll build an email masker that will take an email address and obscure it.

curriculum/challenges/_meta/lab-email-masker/meta.json

@@ -0,0 +1,11 @@
+{
+  "name": "Build an Email Masker",
+  "isUpcomingChange": true,
+  "usesMultifileEditor": true,
+  "dashedName": "lab-email-masker",
+  "order": 153,
+  "superBlock": "front-end-development",
+  "challengeOrder": [{ "id": "66b205e6eacba4c4e54ea434", "title": "Build an Email Masker" }],
+  "helpCategory": "JavaScript",
+  "blockType": "lab"
+}

curriculum/challenges/english/25-front-end-development/lab-email-masker/66b205e6eacba4c4e54ea434.md

@@ -0,0 +1,102 @@
+---
+id: 66b205e6eacba4c4e54ea434
+title: Build an Email Masker
+challengeType: 14
+dashedName: build-an-email-masker
+---
+
+# --description--
+
+In this lab, you will mask the username part of an email address with asterisks. Masking is a term used to hide or replace sensitive information with asterisks or other characters.
+
+For example, if the email address was `myEmail@email.com`, then the masked email address will be `m*******l@email.com`.
+
+**Objective:** Fulfill the user stories below and get all the tests to pass to complete the lab. 
+
+**User Stories:**
+
+1. Create a function named `maskEmail` that takes `email` as an argument.
+2. Inside the function, you should mask the `email` and append the domain name to it.  Remember that you can use methods like `slice`, `repeat`, `indexOf` `slice` or even `replace` to help you.
+3. Outside the function, declare a variable named `email` to store the email address you want to mask.
+4. Call the `maskEmail` function with the `email` variable and output the result to the console. 
+5. `maskEmail("apple.pie@example.com")` should return `"a*******e@example.com"`.
+6. `maskEmail("freecodecamp@example.com")` should return `"f**********p@example.com"`.
+
+# --hints--
+
+You should define a funtion named `maskEmail`.
+
+```js
+assert.isFunction(maskEmail);
+```
+
+The `maskEmail` funtion should take a string, `email` as an argument.
+
+```js
+assert.match(maskEmail.toString(), /\s*maskEmail\(\s*\w+\s*\)/);
+```
+
+Outside the function, you should have an `email` variable.
+
+```js
+assert.isDefined(email);
+```
+
+You should assign a valid email address to your `email` variable.
+
+```js
+assert.match(email, /^[\w\.-]+@[a-zA-Z\d\.-]+\.[a-zA-Z]{2,}$/);
+```
+
+`maskEmail("apple.pie@example.com")` should return `"a*******e@example.com"`.
+
+```js
+assert.strictEqual(maskEmail("apple.pie@example.com"),"a*******e@example.com");
+```
+
+`maskEmail("freecodecamp@example.com")` should return `"f**********p@example.com"`.
+
+```js
+assert.strictEqual(maskEmail("freecodecamp@example.com"), "f**********p@example.com");
+```
+
+Your `maskEmail` should produce the correct result.
+
+```js
+assert.strictEqual(maskEmail("johnappleseed@email.com"), "j***********d@email.com");
+assert.strictEqual(maskEmail("john.doe@example.com"), "j******e@example.com");
+assert.strictEqual(maskEmail("jane.smith@sample.org"), "j********h@sample.org");
+assert.strictEqual(maskEmail("michael.jordan@testmail.net"), "m************n@testmail.net");
+```
+
+You should log the function call to `maskEmail` to the console.
+
+```js
+assert.match(__helpers.removeJSComments(code), /console\.log\(maskEmail\(email\)\)/);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```js
+
+```
+
+# --solutions--
+
+```js
+function maskEmail(email) {
+  const atIndex = email.indexOf("@");
+  const userName = email.slice(0, atIndex);
+  const domain = email.slice(atIndex);
+
+  const maskedName =
+    userName[0] + "*".repeat(userName.length - 2) + userName[userName.length - 1] + domain;
+
+  return maskedName;
+}
+
+const email = "apple.pie@example.com";
+console.log(maskEmail(email));
+```