A reproducible test log records each test so precisely that another person can repeat it and get the same result. It also records what you changed after a failure, so the log tells the story of your own improvements.
This lesson is part of web development without assessed-project substitution. It goes further than a general work log, which records decisions and help, by fixing the exact inputs and results of each test.
What must a reproducible step contain?
Four things: the starting state, the exact input, the ordered actions and the expected result. Missing any one makes the test open to guessing.
| Element | Weak | Reproducible |
|---|---|---|
| Starting state | (none) | “Fresh page load, all boxes empty” |
| Input | “a bad mark” | “Mark box: 105” |
| Actions | “try it” | “Click Check once” |
| Expected | “error” | “Message: Mark must be 0 to 100” |
Worked example: one fault, before and after
A fictional mark checker accepts a mark from 0 to 100 and shows “Pass” from 50.
| ID | Steps | Input | Expected | Actual | Result |
|---|---|---|---|---|---|
| T1 | Load page, type in Mark box, click Check | 72 | Pass | Pass | Pass |
| T2 | Load page, type in Mark box, click Check | 50 | Pass | Fail shown | Fail |
| T3 | Load page, type in Mark box, click Check | 105 | Error message | Pass | Fail |
T2 fails because the condition says mark > 50 where it needs mark >= 50. T3 fails because nothing checks the upper limit.
After the student edits the code, the log continues.
| ID | Change made | Re-test actual | Result |
|---|---|---|---|
| T2 | Changed > to >= |
Pass | Pass |
| T3 | Added a check for marks above 100 | Error message | Pass |
| T1 | (re-run, no change) | Pass | Pass |
T1 is re-run even though it already passed, to show the changes broke nothing. The table lets a reader see the full sequence: fail, change, pass.
The mistake: “tested, works”
A typical weak log reads: “Tested the checker with some marks. Works.” It gives no inputs, no steps, no expected results and no record of a failure.
Nobody can repeat it, and you cannot learn from it either. A week later you will not remember which marks you tried.
How do I check that my log is reproducible?
Hand your log to a classmate who has not seen the page and ask them to run T2. If they cannot produce the same result from your words alone, the step needs more detail.
Also check that the log contains only your own tests and changes. The change column should say what you did, in your words, so it reflects your own reasoning.
Check yourself
Turn this into a reproducible step: “Checked the name box with something weird.”
Answer
One version:
- T7. Start: page loaded with all boxes empty.
- Steps: type 12345 in the Name box, click Submit once.
- Expected: message ‘Name must contain letters only’.
- Actual and Result: filled in after you run the test.
It fixes the starting state, exact input, actions and expected result. Nothing is left to guess.
What to study next
Put everything together with the cluster practice set. If you want a teacher to review your test log with you, see online one-to-one Computer Science tuition.