How we can use faker in Postman v 7.2

Ask the Experts and Postman Tips
1

Now postman support faker library in v 7.2

How we can use it any code example ?

I want to create some fake data in pre request script.

2

Hey @mehran.shafqat

You will find more information about it here, these are dynamic variables and would work in the same places that {{$randomInt}} can be used.

1 Like
3

well why this is not working in pre-req script

var x = “{{$randomInt}}”
console.log (x)

its not printing any random value

4

Taken from the dynamic variables section:

https://learning.getpostman.com/docs/postman/scripts/postman_sandbox

Note that dynamic variables cannot be used in the Sandbox. You can only use them in the {{…}} format in the request URL / headers / body.

{{$guid}}: Adds a v4 style guid
{{$timestamp}}: Adds the current timestamp
{{$randomInt}}: Adds a random integer between 0 and 1000

5

That’s expected behavior because in pre-request script the variables are not resolved.

There’s a workaround:

const {Property} = require('postman-collection');

let randomInt = Property.replaceSubstitutions("{{$randomInt}}");

console.log(randomInt)

We are planning to add an API for variable substitution in scripts.
Please follow the original GitHub feature request for more updates.

2 Likes
6

I’ve seen many of these new random variables available now in the API and I have used in the app but they are not “resolved” when the test is run via Newman.

7

Hey @alkamist-dgrandfield,

What version of Newman are you running this against?

8

Hi all,

a bit late to the party, but since I found a working solution, I wanted to share with you.

The faker.js file needs to be on a webserver accessible by postman.
So what I did is to create a public Bitbucket repo (guess github would work as well), and put all files and subdirectories from https://github.com/Marak/faker.js/tree/master/build/build into it.
I then viewed the faker.js file in RAW mode in Bitbucket and copied the URL, this is what I will be using as faker_js_url in the Postman pre-request-sccript.

And this is a snippet to be used in the pre-request-Script, of course you can easily save the generated values in an environment variable for later re-use:

pm.sendRequest(faker_js_url, (err, res) => {
const faker = res.text();
(new Function(faker))();
    var name = window.faker.name.findName();
    console.log (name);
});

(Inspired by Adding external libraries to postman)

What I´m currently struggling with, is setting the faker locale.
Any help with that is much appreciated.

9

Hello there Christian,

This is what worked for me to get the faker locale working in the test script:

window = {};
pm.sendRequest("https://cdnjs.cloudflare.com/ajax/libs/Faker/3.1.0/faker.min.js", (error, response) => {
var text = response.text();
(new Function(text))();

window.faker.locale = "de";
var name = window.faker.name.findName();

console.log(name);

pm.globals.set("name", name);
})
1 Like
10

Hi @dblom … How to set an Arabic Locale.

The below code is failing.

window = {};
pm.sendRequest("https://cdnjs.cloudflare.com/ajax/libs/Faker/3.1.0/faker.min.js", (error, response) => {
var text = response.text();
(new Function(text))();

window.faker.locale = "ar";
var name = window.faker.name.findName();

console.log(name);

pm.globals.set("name", name);
})
11

Hi,

can somebody please explain how to set locale to some country, to get random data (address, postal code, city…) just from that country?

I found this post Postman
but it seems to me it is perhaps outdated, because it won’t work with other countries (other than France).

I am trying to GET data in pre-request script and pass the values:

window = {};

pm.sendRequest(“https://cdnjs.cloudflare.com/ajax/libs/Faker/3.1.0/faker.min.js”, (error, response) => {
if (error || response.code !== 200) {
pm.expect.fail(‘Could not load external library’);
}

eval(response.text());

window.faker.locale="gb";
pm.variables.set("FirstName", window.faker.name.firstName());   
pm.variables.set("LastName",  window.faker.name.lastName());
pm.variables.set("line1", window.faker.address.streetName());
pm.variables.set("postal_code", window.faker.address.zipCode());
pm.variables.set("city", window.faker.address.city());
pm.variables.set("state", window.faker.address.state());
pm.variables.set("phoneNumber", window.faker.phone.phoneNumber());

});

Is there a way to use postman {{$random}}, but limit result to specific country or city?

EDIT: trick is to use locale codes as shown here in faker.js documentation https://fakerjs.dev/guide/localization.html