End-to-end testing with Cypress series: 03 Real-world tests

In this video, learn about the kinds of end-to-end tests that are most valuable to write with Cypress. After watching this video, you will know which scenarios to test in your application and how to structure end-to-end tests to improve test suite performance.

You will learn:

• what real-world, happy path tests are
• what unhappy path tests are
• why end-to-end tests should cover realistic, happy path scenarios and align with business requirements
• how testing every scenario in your application can hurt test suite performance and maintainability

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00:00

(happy music)

00:03

Welcome back to Test Double's intro course

00:06

on End-to-end Testing with Cypress.

00:09

In the last video, you installed Cypress,

00:12

initialized a test suite, and wrote your first test.

00:16

Before diving deeper into testing with Cypress,

00:19

you will learn more about the kinds of tests

00:21

that are valuable to write with Cypress.

00:23

In this video, you will:

00:25

learn what real-world, happy path tests are,

00:29

learn what unhappy path tests are,

00:31

learn the importance of writing business-valuable tests,

00:35

and learn how the number of end-to-end tests

00:38

impacts test suite speed and maintenance.

00:41

Let's get started.

00:43

So, what is a real-world happy path test?

00:46

Let's explore each of those concepts.

00:49

In the context of end-to-end testing,

00:51

real-world test is a phrase I use to describe a test

00:55

that mimics the flow a real user

00:57

would take with an application.

00:59

For example, on a web app for booking flights,

01:03

a real-world test could be searching

01:05

for round trip tickets given travel dates,

01:08

selecting a flight from the available options,

01:11

choosing airplane seats,

01:13

providing traveler information, and confirming the booking.

01:17

Those are all steps a real user would take,

01:20

so you would include all of those steps in a single test.

01:24

That may sound counterintuitive if you're more familiar

01:27

with unit tests where you typically handle

01:29

multiple test cases, each with a single assertion.

01:33

End-to-end tests are sometimes known as feature tests

01:36

because they usually run through a feature

01:38

that is driven by business requirements.

01:41

In other words, end-to-end tests should ideally align

01:44

with business requirements to verify a software team

01:47

is building what is being asked for.

01:50

Another reason for putting so many steps

01:52

in one test is speed.

01:54

Remember, from the first video, that, typically,

01:57

end-to-end tests are slow because they involve

01:59

the full software stack and drive a real browser.

02:03

If you break up an end-to-end test

02:05

into multiple smaller tests, you multiply the high cost

02:09

of data setup, running through the whole stack,

02:12

and driving the browser for each test.

02:15

Returning back to our beginning definition,

02:17

these tests are usually also happy path tests.

02:21

A happy path test is a real-world test

02:24

that mimics the ideal or best case user scenario.

02:28

Our previous flight booking example is a happy path test.

02:32

The user in the test successfully books a flight

02:35

with no issues during any of the steps.

02:38

An example of an unhappy path

02:40

would test that one or more of the steps fail

02:43

and would ensure that an appropriate error message

02:46

or recovery path is presented to the user.

02:49

Although it's valuable to know your application

02:51

handles exceptions appropriately,

02:54

if you try to test all failure scenarios

02:57

you will drastically slow down

02:58

what is already a slow test suite.

03:01

Also, recall that end-to-end tests are harder to debug

03:04

because there are more points in the stack

03:06

that could cause your test to fail unexpectedly.

03:09

The more end-to-end tests you have,

03:12

the harder it will be to maintain them

03:13

if you encounter unexpected failures

03:16

because you're spending time debugging tests.

03:19

We will revisit this in a later video,

03:21

but there are some ways to reduce the cost of speed

03:24

and debugging in order to test expected failure scenarios

03:28

if your team finds those tests valuable.

03:30

Given all those reasons, Test Double generally recommends

03:34

limiting end-to-end tests to the most business-valuable,

03:37

realistic, happy path scenarios in your application.

03:41

Let's recap what you learned in this video.

03:44

You learned what real-world happy path tests are,

03:48

what unhappy path tests are,

03:50

the importance of writing business-valuable tests,

03:54

and how the number of end-to-end tests

03:56

impacts test suite speed and maintenance.

03:59

In the next video, you will write a real-world

04:01

happy path test for the yams application

04:04

as well as learn new commands

04:06

and selectors for interacting with forms.

04:08

(happy music)

« Start at the beginning

‹ End-to-end testing with Cypress series: 02 Getting Started

End-to-end testing with Cypress series: 04 Happy path tests ›