Module 1 · What testing actually is Lesson 2 of 15
The test case worth writing
A test case is a condition, an input and an expected outcome that somebody else can execute identically. If two testers get different results from your case, it is not a test case yet.
The concept
A test case is one check with an expected result: an id, a short title, the precondition, the steps, the expected outcome and the actual outcome once you run it. It exists so somebody else can run the same check next month and get the same verdict.
Write the ones that carry risk first — money, login, data loss, anything a customer would call about — and keep the coverage visible in a sheet or a tool so nobody has to guess what has been checked. A test case that cannot fail is not a test case: "verify the page loads" passes even when the page is wrong.
id,title,steps,data,expected,priority
TC-01,Login valid,open /login; enter email; enter pwd; click sign in,valid user,dashboard shown,High
TC-02,Login wrong pwd,same steps,bad pwd,error message shown,High
TC-03,Empty email,leave email blank,blank email,validation error,Medium
TC-04,Password 7 chars,enter a 7-char pwd,short pwd,validation error,MediumCommon mistakes
The mistakes are vague expectations ("should work properly") and steps that depend on your own data ("login as the user I created"). Name the account, the record and the value, or the case is not repeatable and will be run once and abandoned.
Worked example
For an age field accepting 18 to 60: 17 must be rejected, 18 accepted, 60 accepted, 61 rejected, empty rejected, "abc" rejected. Six cases, written before any tool is opened — that list IS the skill.
Your practice task
Write a full test-case sheet for a signup form: at least fifteen cases including boundaries and one that would only fail if somebody used the wrong operator.
Do this before moving on. Reading a solution teaches the shape of it; typing it teaches you.
Key takeaway
A test case is one check with an expected result: an id, a short title, the precondition, the steps, the expected outcome and the actual outcome once you run it.
Keep your place in this course
A free account saves which lessons you have finished and unlocks the certificate. The lesson itself stays free to read.
Create free account or sign inCourse complete
You finished every lesson.
Your certificate is ready, and the projects you built are the proof to attach to an application.
Almost there
15 lessons left of 15
Finish every lesson to unlock the certificate. Each one ends in a practice task — do them and the final project brief writes itself.