API testing can get messy fast. You deal with deeply nested JSON, inconsistent response structures, repetitive validations, and way too much boilerplate. Lodash cuts through all of that. And since Requestly exposes Lodash globally as _ inside your Script Tab, you can start using its utilities instantly, no importing or setup required.This article breaks down how Lodash actually makes API testing easier, with examples you can plug straight into your Requestly scripts.
Why Lodash Is a Game-Changer for API Testing
Most API testing involves tasks like:
- Extracting values from deeply nested response objects
- Filtering arrays
- Checking for missing fields
- Comparing expected vs actual data
- Transforming inconsistent data
- Creating small helpers on the fly
Doing all that with plain JavaScript works… but it’s verbose, error-prone, and annoying. Lodash gives you battle-tested helpers that simplify all of these into one-liners.
Using Lodash Inside Requestly Scripts
You don’t need to install or import anything. Lodash is already available globally as _ inside Requestly’s scripting environment. console.log(_.toUpper('requestly')); // REQUESTLY This means you can clean, inspect, validate, and transform data right where you're testing.
Practical Use Cases for API Testing
1. Check if a Field Exists
if (!_.has(responseBody, 'data.user.email')){
console.log('❌ Missing email field');
}
2. Validate That Two Responses Match
const expected = { status: 'active', plan: 'premium' };
const actual = responseBody.profile;
if (_.isEqual(expected, actual)) {
console.log('✔️ Profile matches expected structure');
}
3. Filter Arrays Cleanly
const activeUsers = _.filter(responseBody.users, u => u.active);
console.log('Active:', activeUsers);
4. Map Data for Assertions or Next Requests
const names = _.map(responseBody.users, u => u.name);
console.log('User names:', names);
5. Safely Get Deep Values
const role = _.get(responseBody, 'data.profile.role', 'unknown');
console.log('Role:', role);
6. Remove Unwanted Fields Before Passing Data Forward
const sanitized = _.omit(responseBody.user, ['password', 'token']);
console.log(sanitized);
Why Lodash Fits Perfectly With Requestly’s Script Runner
Lodash shines in scenarios like:
- Writing assertions in response scripts
- Cleaning API responses before chaining requests
- Normalizing data for comparison
- Generating structured logs
- Avoiding brittle manual validations
If you run multi-step workflows or collection runs in Requestly, Lodash quickly becomes your go-to toolkit.
More Tools Available in Requestly
Requestly provides many other global utilities, third party plugins, and helpful libraries that you can use instantly inside scripts. Learn more here: Import Packages into Your Scripts
Final Thoughts
Lodash doesn’t just simplify API testing, it removes friction entirely. Shorter scripts, clearer logic, fewer bugs. And since Requestly includes Lodash globally as _, you can use it instantly without any setup.