DEV Community: Daphné Hervé

[Postman] The variables

Daphné Hervé — Sat, 23 Mar 2024 11:22:47 +0000

From advanced to expert 
For developers and testers.  
         ---------          
Some great tutorials to get all the tips of Postman :

Number 2 : Let's continue the tutorials with the variables.
In the previous tutorial we written some javascript in the test section to get data from the console. Postman offer a storage feature for this data.

That means :

we can use getter and setter inside postman
we can reuse data for a request chain for e2e tests and automation
We can secure bearer token as secret using the variables

For this tutorial we will use the free API of national french repository of adresses (--> documentation - FR)

Create a new request and type this call :

https://api-adresse.data.gouv.fr/search/?q=8+rue+port

Feel free to enter the adresse of your choice ;)

Click the send button to submit the request and enjoy the 5 results.

Alright, it's time to play with variables !

Firstly we will iterate on the results to get each adresse name :

let adresses = pm.response.json()
adresses.features.forEach(adresse => console.log(adresse.properties.label))

Submit the call and enjoy the results in the dev console :

Each adresse label is properly retrieved.
Secondly, we will store the results in a collection variable.

let adresses = pm.response.json()
// Setter
pm.collectionVariables.set("adresse_label_variable", adresses.features[0].properties.label);

Super nice ! And we add a getter :

// Getter
let firstAdresse = pm.collectionVariables.get("adresse_label_variable");
console.log('stored_variable', firstAdresse);

Should be like this :

Well done ! We used setter and getter to store the first result and reuse it in a console.log

Good to know : collectionVariables is not the only way to store data.

CollectionVariable = Manage data into the collection only
EnvironmentVariables = You can reuse data from one collection to another
GlobalVariables = Use it everywhere.

(Official Postman Documentation)

You can find the environment on the right corner at the top :

To see all your collectionVariables go there :

To see the other variable types see here :

In the next tutorial we will learn to use the
environmentVariables and how to store secret data

See all the official postman documentation here

Hope it helps !
Daphné Hervé (API, monitoring and QA automation lover)

[Postman] The dev console

Daphné Hervé — Sat, 23 Mar 2024 11:22:15 +0000

From advanced to expert 
For developers and testers.  
         ---------          
Some great tutorials to get all Postman tips :

Number 1 : we begin the tutorials with the dev console.
The console is very useful when you are coding your front or for testing purpose.

Breaking news - we will write some javascript inside !

For this tutorial we will need the dev console itself just here :

In the left corner on the bottom.

And the test tab in the request part, just here :

Create a get request to the free pokemon api without any parameters just this call :

https://pokeapi.co/api/v2/pokemon

Should be like that :

Press the send button for submitting our request !
Alright, so far everything ok !

Let's take a deeper look to our main subject by clicking the console button on the bottom

All the call informations are properly retrieved.
And so what ?

Wait a minute, I mentioned some javascript, let's go !
Go to the test tab and write some js :

let pokemons = pm.response.json().results
pokemons.forEach(pokemon => console.log(pokemon.name))

Should seems like that :

Click on the send button to see the result in the console !
Awww wow ! We have it ! A wonderful pokemon list !

We achieve our first goal : Use the postman console for debugging or testing.

Additional tips : you can clear the console on the right corner on bottom of postman.

Next steps :

Learning to use variables to do something with the pokemon list or any data you get.
Manage your environnement and keep your infos secret
Go further in the javascript methods
Learn to use the mock server
Go deeper with the automation ... and several very useful things !

Hope it helps !
Daphné Hervé (API, monitoring and QA automation lover)

Test less and cover more with combinations using Pairwise and Pict

Daphné Hervé — Mon, 11 Mar 2024 04:35:07 +0000

Go straight to the point ! 
Test less and cover more, 
sounds good !

When ? You have a lot of data or different behaviors to test.

Who ? For developers and testers who want to reduce their number of tests cases.

How does it work ?

"Pairwise testing is an effective test case generation technique that is based on the observation that most faults are caused by interactions of at most two factors. Pairwise-generated test suites cover all combinations of two therefore are much smaller than exhaustive ones yet still very effective in finding defects"
(Pairwise.org)

In this post we will use PICT to generate efficient combinations of data at entry point of your test cases. Pict is an open source CLI tool developed by Microsoft.

Form your own opinion by using this great online console : https://pairwise.yuuniworks.com/

How to use ?
Download the Pict.exe and open a terminal.
It's an .exe, so you need to be on the same folder or to indicate the right path to the Pict.exe.

Pict my_file_to_combine.txt

💡 Tips : render the results in an external file instead of in the command line interface using a return function :

Pict my_file_to_combine.txt > results.csv

📝 Pict is also available with a container image. Go to the README to have more infos : README on github

Imagine a database with CRUD authorizations combined with user rights. You need to test if the action of the user properly depends on the right authorization.

Some usual exemples :

reader can only see the user-infos-table
contributor can create into the user-infos-table
admin can also update the localization-table
admin is authorized to delete / localization-table ... etc etc.

Without the Pairwise method, we would need to do several iterations for this test to cover all the possibilities.

Let's try the Pairwise method ! Such of entries...

#############################################################
# User's access to your database
#############################################################

userTypes: reader, admin, contributor, editor

accessTypes: view, create, read, update, delete

database name: user-infos, localization

... give the followings results :

userTypes   accessTypes   database name
admin       read          localization
admin       delete        user-infos
contributor create        user-infos
admin       view          localization
editor      create        localization
reader      delete        localization
editor      view          user-infos
contributor update        localization
editor      read          user-infos
editor      delete        localization
editor      update        user-infos
contributor view          localization
admin       create        localization
contributor read          localization
admin       update        user-infos
reader      view          localization
contributor delete        localization

Seems like a .csv file. The first row is the header with all the entries we mentioned.

Without the Pairwise method, in the following case we would need to do at least 32 iterations for this test to cover all the possibilities.

With the Pairwise generation method we get 17 results. Amazing !

Now we can add some additional restrictions :

if [userTypes] = "reader" then ([accessTypes] = "view");

#############################################################
# User's access to your database 
#############################################################

userTypes: reader, admin, contributor, editor

accessTypes: view, create, read, update, delete

database name: user-infos, localization

if [userTypes] = "reader" then ([accessTypes] = "view");

And the results are ...

userTypes   accessTypes   database name
admin       read          localization
admin       delete        user-infos
contributor create        user-infos
admin       view          localization
editor      create        localization
editor      view          user-infos
contributor update        localization
editor      read          user-infos
editor      delete        localization
editor      update        user-infos
contributor view          localization
admin       create        localization
contributor read          localization
admin       update        user-infos
reader      view          localization
contributor delete        localization

More details here about the Pairwise combination method : Pairwise.org

You can find some useful examples of restriction in the official documentation

The time you win with this Pairwise method is precious to any other test action ! Think about exploratory testing !

Hope it helps !
Daphné Hervé (API, monitoring and QA automation lover)

[Postman] Set random numbers in your test name

Daphné Hervé — Mon, 11 Mar 2024 04:26:39 +0000

Love sharing my best postman recipes, today a precious advice

To set dynamically a variable in your test name.

pm.test(["TEST - " + pm.variables.replaceIn('{{$randomInt}}')], function () {
    pm.response.to.have.status(200);
});

You will get random value in the the name on the TSF report.

Appreciate the result :

There is a lot of very useful value with the Faker library :
$timestamp or $randomAlphaNumeric

Take a look here for more details about all the ramdom value that you can use : Official documentation about this topic

Hope it's help !
Daphné Hervé (API, monitoring and QA automation lover)