Postman Beginner Tutorial 13 | Data Driven Testing | How to get data from CSV and JSON files

Summary

This tutorial by Raghav introduces data-driven testing with Postman, guiding viewers step-by-step to create API requests, parameterize them with data from CSV and JSON files, and execute data-driven API tests. It also covers referencing data in test scripts, validating JSON data, and running tests with Postman's collection runner, ensuring a comprehensive understanding of the process.

Takeaways

• 😀 The tutorial is about learning data-driven testing with Postman from scratch.
• 🔍 Raghav, the instructor, guides through the process of setting up data-driven API requests using Postman.
• 📝 The script covers how to get data from both CSV and JSON files for testing purposes.
• 💻 Postman can be accessed either through a browser or a desktop application.
• 📥 The process includes creating an API request, modifying it, and saving it in a collection for organization.
• 🔑 Variables are parameterized within the request to refer to data from external files.
• 📈 Raghav demonstrates how to create and use a CSV file with sample data for the API request.
• 📊 The tutorial also shows how to create and validate a JSON file for similar purposes.
• 🔄 Postman's Collection Runner is used to execute API requests with data from the files.
• 📋 The script explains how to refer to data from the files within test scripts using specific syntax.
• 🛠 The importance of validating JSON data for correctness is highlighted to avoid errors in testing.

Q & A

What is the main topic of the video?

The main topic of the video is how to perform data-driven testing with Postman, starting from scratch.

What are the data sources mentioned for data-driven testing in Postman?

The data sources mentioned for data-driven testing in Postman are CSV and JSON files.

How does one create an API request in Postman as shown in the video?

In the video, an API request is created by clicking the plus button in Postman, selecting an API from the 'req res dot in' website, copying the endpoint, and pasting the request body as JSON.

What is the purpose of saving the API request in a collection?

Saving the API request in a collection helps organize and manage the requests, making it easier to run multiple related requests together and maintain a clean structure.

How can you parameterize parts of the API request in Postman?

Parts of the API request can be parameterized by using double curly brackets and the variable name, such as '{{endpoint}}', '{{email}}', and '{{password}}'.

What tool can be used to create a CSV file on a Mac system?

On a Mac system, the Numbers application can be used to create a CSV file, which is similar to Excel.

How does the video demonstrate the use of a CSV file for data-driven testing?

The video demonstrates the use of a CSV file by showing how to create it in Numbers, fill it with data corresponding to the API request parameters, and then use it in the Postman collection runner.

What is the significance of the '201 Created' status code mentioned in the script?

The '201 Created' status code signifies that a new resource has been successfully created in response to the POST request in the API.

How can you verify the validity of JSON data before using it in Postman?

You can verify the validity of JSON data by using online JSON formatters or validators, which check the syntax and structure of the JSON file.

What is the difference between using data variables in Postman directly and using them in data files?

In Postman, using data variables directly involves referencing them with double curly brackets. However, when using data files, you must reference the data with 'data' followed by the variable name or header name in square brackets, such as 'data[email]'.

How can you run tests within the API request in Postman?

Tests can be run within the API request in Postman by writing test scripts in the 'Tests' tab of the request. These scripts can validate the response, such as checking if the status code is '201'.

What is the importance of clearing the console before running a new collection in Postman?

Clearing the console before running a new collection in Postman ensures that the output is clean and only displays the results of the latest run, making it easier to analyze and understand the results.

Outlines

00:00

🚀 Introduction to Data-Driven Testing with Postman

Raghav introduces the tutorial on data-driven testing with Postman, outlining the process of learning from scratch. The session includes extracting data from CSV and JSON files and executing API requests with this data. Raghav demonstrates how to create an API request in Postman, using a sample 'register user' POST request from a website, and explains how to modify the request method, URL, and body. He also shows how to save the request in a new or existing collection and how to parameterize the request using variables that will later be populated from data files.

05:00

📝 Creating and Using Data Files for API Testing

This paragraph explains how to create test data files in CSV format using a Mac application similar to Excel or by using a text editor on Windows. Raghav details the steps to input data corresponding to the variables used in Postman, such as endpoint, email, and password, and how to save the file with a '.csv' extension. He also describes how to run a collection in Postman with the data file selected, which automatically updates the iterations based on the number of data sets in the file. The importance of previewing data to ensure proper format and the steps to correct any discrepancies are also covered.

10:02

🔍 Validating and Using JSON Data Files in Postman

Raghav demonstrates how to create and validate JSON data files for use in Postman. He explains the process of manually creating a JSON file using a text editor and emphasizes the importance of validation using online tools like JSON formatters and validators. The tutorial includes a step-by-step guide on how to structure the JSON data with proper syntax and how to download or copy the validated JSON data into a file. Raghav then shows how to select this JSON file in Postman's collection runner and how it updates the iterations for data-driven testing.

15:02

📚 Referencing Data in Test Scripts and Pre-Request Scripts

The paragraph discusses how to reference data from data files within test scripts or pre-request scripts in Postman. Raghav clarifies the difference in syntax required for data references when using data files compared to variables within Postman. He provides an example of creating a test to verify the email in the response body and explains the correct syntax for accessing data from the data file during test execution. The summary includes a demonstration of running the collection with the test script and confirms that the test passes when the email from the data file matches the response.

20:02

🎓 Conclusion and Encouragement for Further Learning

In the concluding paragraph, Raghav wraps up the tutorial by summarizing the process of using data files for data-driven API testing in Postman. He encourages hands-on practice and invites questions from the audience, emphasizing the importance of continuous learning in the field. The paragraph serves as a final reminder of the value of the tutorial and an invitation for further engagement with the content.

Keywords

💡Data-driven testing

Data-driven testing is a method of software testing where test cases are designed to cover a wide range of input data to ensure the application behaves as expected with different inputs. In the video, Raghav teaches how to implement this approach using Postman, a popular API development tool, by getting data from CSV and JSON files to run API requests with different sets of data.

💡Postman

Postman is a collaboration platform for API development used by developers to build, test, and monitor APIs. In the script, Postman is the primary tool used to demonstrate how to create API requests, parameterize them with data from external files, and execute data-driven tests.

💡CSV file

A CSV file, or Comma-Separated Values file, is a simple file format used to store tabular data, such as a spreadsheet or database. In the video, Raghav explains how to create a CSV file, populate it with endpoint, email, and password data, and use it for data-driven API testing in Postman.

💡JSON file

JSON, or JavaScript Object Notation, is a lightweight data-interchange format that is easy for humans to read and write and for machines to parse and generate. The video script describes how to create a JSON file with data for endpoint, email, and password, and integrate it with Postman for data-driven testing.

💡API request

An API request is a message sent from a client to an API server with the purpose of accessing or modifying data. In the context of the video, Raghav shows the process of creating a 'register user' API request in Postman, which is then used for demonstrating data-driven testing.

💡Parameterization

Parameterization in the context of API testing refers to the process of replacing static values in API requests with variables that can be dynamically replaced with data from external sources. The script illustrates how to parameterize parts of an API request in Postman using data from CSV and JSON files.

💡Collection

In Postman, a collection is a group of related API requests that can be organized and run together. Raghav demonstrates saving an API request into a new collection named 'data driven demo' and later running this collection with data from a CSV file.

💡Test scripts

Test scripts in Postman are used to write test cases that can be executed after an API request is sent. The script mentions adding test scripts to verify the status code of the API response and to validate that the email received in the response matches the email sent in the request.

💡Environment variables

Environment variables in Postman are a way to manage different sets of data that can be applied to API requests. Although the script does not focus on environment variables, it mentions the possibility of using global or environment variables for parameterization, which can be an alternative to using data files.

💡Validation

Validation in the context of the video refers to the process of ensuring that the data in the CSV and JSON files is correctly formatted and that the files contain valid data for testing. Raghav shows how to validate JSON data using online tools and emphasizes the importance of this step before using the files in Postman.

💡Console

The console in Postman is a debugging tool that displays the output of API requests, including the request and response bodies. In the script, Raghav uses the console to demonstrate the results of running data-driven tests and to show how the data from the CSV and JSON files is used in the API requests.

Highlights

Introduction to data-driven testing with Postman.

Learning how to get data from a CSV file for testing.

Exploring how to get data from a JSON file for testing.

Running data-driven API requests in Postman.

Referencing values from data files in test scripts.

Creating an API request in Postman.

Using sample APIs from reqres.in for demonstration.

Copying the endpoint and request body for the API request.

Saving the API request in a new or existing collection.

Creating a folder within a collection for organization.

Running the API request to check the response.

Observing response changes with different endpoint inputs.

Parameterizing the API request using variables.

Creating a CSV file for test data using a spreadsheet application.

Ensuring case sensitivity and correct variable names in the CSV file.

Saving the CSV file and preparing it for use in Postman.

Running a collection with a CSV data file in Postman.

Previewing data from the CSV file within Postman.

Addressing issues with extra columns in the CSV file.

Adding tests to check the status code in Postman.

Running the collection with tests to validate the API response.

Using a JSON file as an alternative to a CSV file for data.

Creating a JSON file with valid JSON data using a text editor.

Validating JSON data using an online formatter and validator.

Running a collection with a JSON data file in Postman.

Referring to data from data files in scripts within Postman.

Conclusion and invitation for hands-on practice and questions.

Transcripts

hello and welcome i am raghav and today

we are going to learn step by step from

scratch how can we do data driven

testing with postman so this will be

very easy and very interesting we will

learn how do we get data from a csv file

we will also see how to get data from a

json file and then we will run our data

driven api requests i will also show you

how you can refer the values from the

data files in the test scripts so let's

get started i will discuss some useful

tips with you as well during the

sessions so here step number one is we

will create our api request first so i'm

going to my postman i have opened my

postman on the browser if you like you

can continue on the browser or if you

are using a postman on your desktop you

can use that

so here uh i'll take i'll create a new

api request so i'm going to click on

this plus button and i will create let

us say i take a

i go to this req res dot in website and

i will select a api request from here

it has a lot of sample apis you can use

any of your api requests so i have this

register user which is a post request i

will click on this

and

here is the

end point this is the request body this

is the response that we get and the

response body so to get the complete url

you can click on this url and you will

get the complete url here

so i'll copy this and first i will

change the method to post

this is the url and i will go to the

body section

and click on draw

and just copy this

body here and this is a json so i will

go here and say json

and this is done and that's it i will

save

and here

i can save it in a new collection or any

of the existing collections first let me

give it a name i will say this is

register user

and here

i will go to the

let us

go to the new collection folder you can

use any collection

and i will save it

so you can see this is saved here

and i can also create a new folder

inside this new collection i can say

add folder

and i will name this folder as

data driven demo

and i'll just put this api inside this

folder this is optional i'm just doing

this so that

we have a clean structure and you can

understand it easily you can keep this

api in any collection and now this is my

api request let us run and check it i

will

click on send once you have saved your

request you can run the request and yes

you can see we are getting the response

we are also getting

the response code 200 okay and

everything is fine now one thing i have

observed here is if i give

some

if i add something to this endpoint let

us say qa

and then i run this

in this case in the response

i get 201

the status quo 201 created and then i

also get the email and the password that

i have sent in the request so if i go

back to the request body this was the

email i sent and the same email i have

received let us say if i change this

email

and

password

and i

save and send it again

you can see i'm getting the same email

and password

so i can use this functionality to

actually check

that i am getting the same

values in the response so this will be

easy for validation so i can use this we

have created a api request now we will

create the variables and refer in the

request so here

i can

parameterize wherever i want to refer

the data from the data files so if you

like like if you want to you can create

variables like global variables or

environment variables and def then refer

them in the request

in this case because i want to refer

them directly from the data files i will

skip the step of creating the variables

i can just refer the variables directly

within this request so let us say i want

to uh get some data for the end point

here so let us say this

this part should come

from a variable

or from a data

file

and this i will name as let us say

endpoint so this is how i do it i give

double curly brackets and then give the

variable name

so this is now parameterized similarly

let us say the email i want to get it

from the data file so i will add a

variable here as well and this i will

call as email so within double curly

brackets you give the variable name and

the same goes for

let us say password as well and

here i will give the variable name as

password

so now these three variables or these

three

data endpoint email and password should

come from a data file like a csv or a

json file so for that we will create a

csv file or a json file and add these

values so that these can be referred

from there so let us do that now

we have to go to run collection and then

refer the data file so before doing that

before going to run collection let us

first create the

files the test data files so here uh

i'm on my mac system so i can go to

xlr numbers application to create a csv

file if you are on windows you can just

open an your

excel file

or excel worksheet

add the data

and save as

dot csv extension

or the other way is you can just

open any text editor or notepad on

windows and add data

in a csv format or comma

separated format

and then save with dot csv extension

let me show you

uh

i'm here on my mac so i will open

numbers which is a application similar

to excel

and here i can create a csv file so i'm

just opening a blank file here

so this is like excel

and here

let me just remove these extra

rows and columns

i will delete this as well

yeah this is fine so this is a excel

file so here i will give the same names

as the variable names i have given which

is endpoint

so this is endpoint let me increase this

so that you can see this properly

endpoint then we have email and make

sure this is should be case sensitive so

uh make sure that

you give the same name exactly how you

have given in the

postman variables and this is

password now here i will start giving

the value so this is the header

then we will have the data rows so let

us say

for the

end point

i will say

i'll give the end point here

then email

and

password

then

again the second

data set you can add any number of data

sets

i will say

i'll give some email

and give some password

and i will save this now

here for mac i have option i can go to

file and say export to csv

in case of windows you just have to save

it and then change the extension to csv

or save it as a csv file so i will save

it as a csv file and

i will call this as

testdata1.csv

and this will go on my documents folder

so this is done

now

i will go to run collection

so here

i will go to this collection click on

these three dots and say run collection

and here i am just going to

select

the api that i want to run which is

register user and here we have the

option to select the file and once i

select the file the iterations will get

updated automatically based on the

number of data sets we have in our file

so i'll click on select file and i will

go to my documents folder and this is my

csv file i will select the file and you

can see it has updated two iterations

because there were two data sets in my

csv file also if you observe

my csv file is added here and that data

file type is updated to text csv so

there are other options as well

application json or undetermined if it

is not able to find what format is it

but it has found it is a csv format so

it has used this and we also have this

very good feature that you can preview

your data so if i click on preview you

can see we are getting all our data and

this is what you should see in a proper

format you should see these headers

which should be same as the variables we

have given and your

data here in case you do not see this in

a proper format then you must change or

you you must check your csv file and

must update the values now one thing i

am seeing here is there is an extra

column so i will have to check this i'll

go to my file and i don't know if this

is

something missing or

i think it should be fine let me just

run and check this

so

here

i will

[Music]

click on run new collection

and let us see

if it is able to

use

our variables or data from the data file

so here

looks fine you can see it is saying 201

created 201 created so this looks fine

and here it does not shows us password

fail because we do not have any tests in

our

api so let me add some tests as well i

will go back to my api go to the test

section and i will just add a test to

check status code is

201 so i'm clicking here in the snippet

and it has added this snippet and i will

just

change to 1 200 to 201

and save it

i'll go back to the collection and i

will say run again

and this time it should also run the

tests so you can see the tests are

running and everything is passed and i

can also go to the console we have

learned this in the debugging session if

i go to this console here i will clear

and run again

and we can see all the output on the

console so it has done it has done two

times if i look at the first run you can

see it has taken this api endpoint from

our data file and if i check the request

body it has taken this email and

password from there

and then

if i see the response body this is how

the response looks like and then for the

second run

this is the second run this is the

end point taken and if i check the

request body this is the request party

email and password taken from that csv

file and this is our

response so this is working fine and we

are able to

run with a csv file let us also see how

we can use a json file

now if you want to create a json file

you can use any notepad or text editor

and add your json data and then save it

as a dot json format

so here

add json data in any

text or

notepad file

and save as

dot json extension now once you do that

you should also

verify that you have a valid json data

and for that we have a lot of

options and tools online so if i search

for

json

[Music]

beautifier or validator

i can

use any of the json formatter

so let me see

if i get some options here

yeah this one is fine let me go to this

one this is json formatter and validator

and this is the url so i can directly

create a json here and then i can

download it or i can copy it in my json

file so to create a json

so i'll give a curly bracket here

start

and stop and within this curly bracket i

will add my data so let us say

the first thing i want to add is the

endpoint

i'll say endpoint within quotes

and then the value of the endpoint

so i'll just copy the value so this is

what i want

i can also just copy from here as well

then i give a comma

and then

the second value

which is

email

and

i give the

value of the email

then comma

and then

the third data

which is password

and the value

i'll give the value of the password and

that's it now this is one set of data if

you want one more set then you give a

comma here

so i give a comma here and just

you can copy the same thing

that is

from the start of this curly bracket

and the end of this curly bracket the

same thing

and here i can change the values

okay

and that's it so this is a valid json

and

you can also click on process to

validate it is a valid json or not and

here i am going to

download it so i will click on download

json so it has got downloaded and there

are many other tools so uh if you just

search for json

formatter

or beautifier

can find a lot of options

so let me check

if you go to google and search for json

beautifier or json formatter you should

see all these options here

let us just wait

for this to give us some options

meanwhile we have got our json file

downloaded and this you can also do the

other way like first you create a json

file and then come here and just

validate that your json is correct so

this is very important to validate that

you have got a valid json and for now

i'll go back and use the json file in

the collection runner

so i'll go here let me clear the

console logs

and i will go back to my collection

and say

run collection

and

i'm just running this api and this time

i will select a

json file so i'm going to the downloads

folder

and this is my json file

and yes everything looks fine

uh if i you can see it has

it has

updated to iterations and this is the

file and it has selected application

json in the file type and we have got a

preview so if i click on preview so

everything looks fine here i can now

say run new collection

and here

everything is running fine it has run it

two times with two sets of data and the

tests are also pass if i look at the

console you can see here

this is my request body

and then

this is the first run this is the

response body and for the second run

this is my

request party here

and you can see everything is taken from

the

json file

so this is how we can

get data from a csv or a json file now

in case you want to

run this you want to refer data from any

of these data files in scripts like a

test script or a pre-request scripts in

that case you will have to use some

different format let me show you if i go

to my api

i will

clear the console

and go back to my

api and let us say i am going to the

tests and i will create

a test

i will call it as

verify email in the response

and here

i will say

response

body

dot hash

and now in case you are referring

this from any variable within postman we

can just give it like this

but this will not work

this will not

work in case of

getting the data from a data file for

that we will have to say

data

dot

email so it will get data from the data

file or the other way is

i can say data

and within square brackets

i will give the

variable name or the header name that is

email so this is how

we use

this if we have to refer data in the

scripts this is how we do this

and let me save this

and i'll run it again just to check this

works fine

so i'll run the collection i'll go to

run collection

and i'll select the

file

you can select csv or json file

and

i will now run and check

so you can see

this is all working fine and verify

email has also

passed if i check the

console output you can see

this is the request body and here the

email is raghav at

req dot in and then if i see the

response body here as well the email is

raghav req dot in and therefore this has

passed so this is how you can refer

data

in apis using data files and i hope this

was very useful for you please do some

hands-on if you have any questions you

can let me know and i will see you in

the next session thank you for watching

and never stop learning