Software Testing Tutorial #24 - Regression Testing in Agile Development

Summary

This tutorial explains regression testing within an agile development approach, particularly in a Scrum framework. It highlights the challenges of manual regression testing across multiple sprints as the number of test cases grows. The solution suggested is automating regression testing by identifying key test cases and building an automated regression suite throughout the development process. Tools like Selenium for UI automation or API-level automation tools are recommended to efficiently manage regression testing in agile projects, ensuring that previous functionalities remain intact as new features are introduced.

Takeaways

• 💡 Regression testing ensures that existing functionality continues to work after new code or features are added.
• ⚙️ In agile development, specifically Scrum, the project is divided into sprints, typically lasting 2-4 weeks.
• 📋 User stories, which represent the project requirements, are assigned to each sprint for development and testing.
• 🧪 Testers write test cases for each user story and test the functionality based on the acceptance criteria during the sprint.
• 🔄 Regression testing ensures that code changes or additions do not break previously working functionalities.
• 🚧 Manual regression testing becomes increasingly challenging with each sprint due to the growing number of test cases.
• 🤖 Automation is a key solution for handling regression testing in agile projects to save time and ensure accuracy.
• ✅ Test cases are prioritized and marked as regression candidates based on their importance and usage frequency.
• 🔧 Automated regression suites are built gradually, sprint by sprint, reducing the need for manual testing.
• 🛠️ Tools like Selenium and API-level testing tools can be used for automating both UI and API regression tests.

Q & A

What is regression testing, and how is it different from retesting?

Regression testing ensures that existing functionality continues to work after code changes, while retesting focuses on verifying if specific defects or issues have been fixed. Retesting is part of regression testing but they serve different purposes.

What is the main challenge of performing regression testing in an agile development approach?

The primary challenge is that with each sprint, the number of test cases grows, making manual regression testing increasingly time-consuming and unfeasible, especially with short development cycles like 2-week sprints in Scrum.

How are test cases organized in Scrum for each sprint?

Test cases are organized based on user stories, which define specific functionalities or requirements. Each user story has acceptance criteria and corresponding test cases, which are tested during the sprint to ensure functionality is as expected.

Why is manual regression testing difficult to manage in agile projects?

Manual regression testing becomes difficult in agile projects because, as more sprints are completed, the number of test cases that need to be re-executed continues to grow. This makes it unfeasible to manually test all cases without significantly increasing the team size.

How can automation help with regression testing in agile projects?

Automation helps by reducing the manual effort required to re-execute test cases. As each sprint progresses, test cases marked as critical for regression are automated, allowing them to be quickly executed in future sprints, saving time and resources.

What criteria should be used to select test cases for automation in regression testing?

Test cases should be selected for automation based on their importance, frequency of use, and impact on the project. It’s essential to prioritize which test cases are most critical, rather than automating all test cases, to build an efficient regression test suite.

What is the role of user stories in agile testing?

User stories in agile testing define the requirements and functionalities that need to be implemented. Each user story includes acceptance criteria, which are used to create corresponding test cases. These stories guide the development and testing processes in each sprint.

How does automation benefit the team in future sprints?

By automating test cases in each sprint, the team can run automated regression tests in future sprints without having to manually re-execute test cases. This increases efficiency and allows the team to focus on testing new functionalities rather than re-testing existing ones.

What tools are typically used for regression test automation?

Common tools used for regression test automation include Selenium for UI testing and various API testing tools. These tools allow teams to automate repetitive test cases and ensure that previously tested functionalities continue to work after code changes.

What is the importance of identifying regression test candidates during sprints?

Identifying regression test candidates during sprints ensures that only the most critical and relevant test cases are included in the regression suite. This prioritization is crucial for managing the increasing number of test cases over multiple sprints and avoiding unnecessary automation.

Outlines

00:00

👋 Introduction to Regression Testing in Agile Development

The first paragraph introduces the concept of regression testing in the context of agile development, specifically focusing on the Scrum framework. The speaker recalls previous lessons about regression testing and its distinction from retesting. The main focus is on understanding how regression testing fits into the fast-paced, iterative nature of agile projects, particularly in two-week sprints. The paragraph explains that agile teams work on 'user stories' and develop and test functionalities during these sprints, with the need to continuously ensure that previously working features remain functional as new code is integrated.

05:01

🔄 Regression Testing Across Multiple Sprints

The second paragraph dives deeper into how regression testing is performed in agile projects. It emphasizes the challenge of executing all test cases from previous sprints in addition to the current sprint’s functional testing. The speaker explains that as new stories and test cases are added in subsequent sprints, the regression suite keeps expanding, making manual regression testing increasingly difficult. As the project progresses, the number of test cases increases significantly, and manually executing all of them becomes unrealistic. The need for a sustainable testing strategy, like automating test cases, is introduced.

10:03

🤖 Importance of Test Automation in Agile Regression

This paragraph focuses on the solution to handling regression testing in agile projects—automation. It explains that automating test cases helps manage the growing number of regression tests across multiple sprints. The speaker suggests marking critical test cases as 'regression candidates' early in the project and automating them. This allows the team to run automated regression tests in future sprints, ensuring that the core functionalities continue to work without requiring manual re-execution of all test cases. The importance of prioritizing and selecting the most impactful test cases for automation is also highlighted, as not every test case needs to be part of the regression suite.

🏃‍♂️ Automating Regression Testing in Scrum

In this final paragraph, the speaker reiterates how automation plays a crucial role in agile regression testing, specifically within the Scrum framework. They discuss the process of building an automated regression test suite over multiple sprints by identifying regression candidates and automating them. Tools like Selenium for UI testing or API automation tools are mentioned as helpful for this process. The automated suite reduces manual testing efforts in future sprints, ensuring efficient and scalable regression testing. The conclusion highlights the benefit of this approach in achieving agile testing goals efficiently.

Keywords

💡Regression Testing

Regression testing is a type of software testing that ensures that existing functionalities of the application work as expected even after new code or features are added. It checks whether recent code changes have affected previously working parts of the software. In the video, the speaker explains how regression testing is crucial in Agile development to verify that new iterations haven't broken previous features.

💡Agile Development

Agile development is a software development methodology characterized by iterative development, where requirements and solutions evolve through collaboration. In this approach, work is typically done in short cycles called sprints. The video explains how regression testing fits into the Agile framework, particularly by ensuring the continuous integration of new functionalities without breaking old ones.

💡Sprint

A sprint is a time-boxed iteration, typically lasting two to four weeks, in which a specific set of features or tasks (user stories) are developed and tested in Agile projects. The video refers to sprints as the central unit of development cycles in Scrum, where regression testing needs to be performed across sprints to ensure functionality remains intact.

💡User Story

A user story is a simplified description of a feature from the perspective of the end user, used in Agile projects to capture requirements. Each story includes functionality and acceptance criteria that developers and testers work on. The video highlights how regression testing ensures that user stories implemented in earlier sprints continue to work as expected when new stories are introduced.

💡Scrum

Scrum is a popular framework for implementing Agile development, which organizes work into sprints. The video uses Scrum as an example of how regression testing is applied in iterative, short development cycles to make sure new updates don’t disrupt existing features. It explains that the Scrum methodology emphasizes short iterations and continuous testing.

💡Automation

Automation in software testing refers to using tools and scripts to automatically execute test cases, reducing manual effort. The video discusses how automation is essential in Agile development, particularly for regression testing, as manually re-executing all tests after each sprint becomes unfeasible due to the increasing number of test cases.

💡Test Cases

Test cases are specific conditions or scenarios used to verify whether a software application behaves as expected. In the video, test cases are written for each user story to ensure that the functionalities meet their acceptance criteria. Over time, selected test cases are marked as candidates for regression testing to be re-executed in future sprints.

💡Sprint Backlog

A sprint backlog is a list of user stories or tasks that the team commits to completing during a sprint. The video references the sprint backlog to explain how regression testing is conducted as new user stories are added in each sprint. It ensures that the backlog of completed tasks from previous sprints remains functional as new features are introduced.

💡Manual Testing

Manual testing is the process of manually executing test cases without the use of automated tools. The video describes how manual regression testing becomes impractical in Agile projects, as the number of test cases increases with each sprint. Automation is suggested as a solution to reduce the effort required for regression testing in future sprints.

💡Progression Testing

Progression testing focuses on verifying the new functionality or changes in the software, ensuring that the newly implemented features work correctly. In the video, progression testing is contrasted with regression testing, where progression ensures the current sprint's features work while regression ensures the previous functionalities remain unaffected.

Highlights

Introduction to regression testing in the agile development approach.

Clarification of the difference between regression testing and retesting.

Explanation of the Scrum framework, its two to four-week development cycle, and sprints.

Description of user stories in agile, including their role in defining functionalities and acceptance criteria.

Manual regression testing challenges in agile projects due to increasing test case volume with each sprint.

Identification of the need for regression testing to ensure existing functionality remains intact after new features are added.

Discussion of the impracticality of manually executing all test cases as the project progresses through multiple sprints.

Importance of prioritizing and selecting the most important test cases for regression testing.

Suggestion to automate regression test cases to reduce manual testing workload in future sprints.

Overview of how to build a regression test suite by identifying regression candidates during functional testing.

Emphasis on selecting and automating high-priority test cases for the regression test suite.

Explanation of how to use automation tools like Selenium for UI testing and API tools for backend automation.

Guidance on continuously building and expanding the automated regression test suite throughout the project.

Suggestion that automating test cases in each sprint reduces future regression testing efforts.

Conclusion: Tackling regression testing in agile by leveraging automation ensures efficient testing as the project scales.

Transcripts

hello everyone welcome again in this

software testing tutorial

we are going to learn regression testing

in

agile development approach so in the

previous tutorial we have understood

what is

regression testing and how it is you

know different

from retesting or you can say retesting

is sort of

part of regression testing but they are

not same so re-testing and regression

testing are different

and i explain i will explain it in the

next tutorial

now in continuation to what is

regression testing when do you do it

you know we also need to understand what

is regression testing in agile or how

you need to basically

uh you know approach regression testing

in agile development approach

so uh if we talk about the agile

development approach

uh say for example you are following

scrum so scrum

is two to four weeks development cycle

now in the two to four weeks development

cycle or iterations which are also known

as prints

so say for example your project follows

two weeks print so what you

will have in two weeks sprint is you

will have the sprint backlog and sprint

backlog is nothing but

the set of stories or the features that

you will be you know

implementing in those two weeks as a

team and

developing that and basically showcasing

or

demoing the working software

after the two weeks or the sprint gets

over right

so say for example if i say sprint one

is your first sprint which is basically

uh you know two weeks cycle okay so in

scrum you will be having you know

two weeks or whatever cadence that you

choose so

if your project has chosen two weeks

sprints then you will be following two

weeks prints until

the completion of the project so in the

two weeks

for example you have picked you know

four stories so story one

story two story three and story four and

stories are nothing but the requirements

in the agile project or scrum so these

stories are basically the

functionalities that will define that

will have the functionalities and the

uh or the requirement and the acceptance

criteria

which is defined in these stories and

these will be implemented in the sprint

right so developers will start working

using these requirements which are

nothing but the stories user stories and

they'll start

developing those user stories testers

will collaborate with developers bas and

they'll start

you know documenting or writing the test

cases and as soon as the functionalities

are available testers will start testing

the stories and ensure that the

acceptance criteria

that is met in these stories is as

expected

right so when we talk about regression

testing in agile

how it is it becomes challenging in

agile

if you cater for the manual regression

testing we'll understand that so say for

example this is the first print

and you have four stories and each story

has say for example this story has four

test cases this has five

this has you know seven and this has ten

test cases right

so these are the test cases that you

have written for these

four user stories to verify that the

functionality that is defined in these

user stories is as

expected right now this is the

number of test cases that you have

written and executed in sprint one

now once print one got over say for

example

here you have executed all of these you

know manually right so there will be

another next print which is sprint two

and in sprint two which is again

next two weeks cycle and in sprint two

you will get another

user requirements right so another user

story is based on the priority say for

example

five six seven eight right so four

stories again

or maybe you know like nine stories

depending on you know capacity

of the team and the size of the stories

so in the next print now you have

five more user stories to actually test

and you are documenting the test cases

for these user stories

okay so you have couple of test cases

written for

these user stories and now these are the

number of test cases that you have

written

for these user stories for sprint two so

you will be doing the progression

testing which is

functional testing of these user stories

in the second sprint

as well as because in the second sprint

the code that has been written in the

first print there will be new addition

to the code

that is written in sprint 1 from sprint

two as well then you need to ensure that

the existing functionality that was

working in sprint one

hasn't broken right so that is what a

regression testing

is to ensure that any existing

functionality of the application

that has already been working prior to

the new implementation

beat addition of the new functionality

which is which is in this case

you know addition of the new

functionality that are part of the user

stories

or if say for example there was a defect

that you raised in sprint one

and that got fixed so you re-executed

so any updates that happen you need to

re-execute

the existing functionality or a subset

of existing functionality

uh based on the addition uh whatever

updation has been done and ensure that

existing functionality

works so in this particular

case what you need to do is you need to

either pick all of these test cases that

you have picked in sprint 1

and re-execute in sprint 2 to ensure

that everything that was passed in

sprint 1

is still working right but that is

really really not feasible in agile

project if you are doing the manual

testing or even if you are doing the

automation testing

so what you do in agile projects um you

know the reason for that is why it is

not feasible so for example there is

another sprint

three okay so they'll be in like 10 15

20 sprints you know until you

release the software it depends how big

your project is

so in sprint three which is another two

weeks you will be having

some more stories right so 10 11

12 13 14 so like four

five more stories there will be you know

new test cases

and then here if you want to execute the

overall

test cases or regression test cases you

have to execute

these plus these and then plus the

functional test cases that you write in

sprint three so with each and every

upcoming sprint your number of test

cases

that need to be executed as part of the

regression suite

will keep increasing right and

that is not possible with the size of

team that you will be having you can't

keep adding new members or new addition

to your team

in each sprint so this is the biggest

challenge

in the agile testing approach right

now how you can tackle it is basically

through

automation right so the first thing is

to basically

if say for example in this particular

sprint

you have couple of test cases so you can

target

as part of the automation you automate

the regression test cases that you have

identified from this list

so in the sprint one as you do the

progression test cases or the test cases

that have been part of these

stories you also keep marking them which

of them are very important and

need to be part of the regression suite

so you

in the tool itself you mark those test

cases as a regression so that your

regression test suite gets

built as you progress with within the

sprint

along with that you need to say for

example out of these four test cases you

marked one as regression candidate

you mark two out of these five as

regression candidates

uh two out of these seven and then two

out of these ten

as a regression candidate you should not

try to include

all of the test cases that you have

tested as part of the functional testing

as

the regression test suite if you are

doing that then you are basically

you know not segregating what is really

important and what is less

important in the project and in a

project or in

the features uh everything can't be

important right so it has to be

prioritized based on the highest

priority or the highest usage

and the low usage and the low priority

so based on that you basically come up

with the test cases that will

form your regression test suite right

and these test suite you try to automate

as you progress along in the sprint in

the agile project

right so say for example now i have you

know seven test cases

uh in the next sprint uh i'll have a

team or i'll have

team members who will automate these

test cases so that

when we are in the next print we can

basically rather than executing these

test cases manually as part of the

regression testing we will

in sprint to run these test cases

with the automation tool so you can use

you know selenium or if you can you are

automating using the api tools

at the api level you can you do the api

test automation

and there are number of tools available

to do the ui automation

so you can use those tools to automate

and

you know once you are in sprint 2 you

have the automated suite ready

then when you go to the sprint 3 you

identify the regression candidates in

sprint 2

automate those and sprint 3 you are

having that

automated test suite built and ready

that is automated regression test suite

and that will

reduce the amount of effort that you

need to put

manually each and every sprint and will

help you to achieve

the regression target and regression

testing in the agile

project and scrum um agile scrum

basically so scrum

is uh the framework uh which is very

widely used

agile used agile development methodology

nowadays right

so this is how you can tackle regression

testing in

agile development approach so that's all

for this tutorial hope it was helpful

please do share and subscribe and thank

you very much for watching