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Playwright · 22 Fixtures and Setup Responsibility
Series contents · Technology map
Stage: Visual Regression and Execution Strategy · External example · preview instructions · Storage ID: playwright-step-22
Goals and learning outcomes
- Learning outcome: explain the role of Fixture. Input cases: a successful test and a failure partway through.
- Deliverable: setup and cleanup logs and remaining files. Explain the rationale for handling Teardown, linking it to the code.
Prerequisites
Prepare the experiment results for Execution evidence and Diagnosis from Unit 21, “Reading Traces”.
Key concepts and explanations
Fixture
A fixture combines repeated setup and cleanup. It must not create hidden global state.
Teardown
Remove temporary files and contexts according to the test lifetime. The cleanup path must run even after failure.
Practice setup
First check the execution scope guidance on the example screen. The following describes the environment needed to extend the assignment in a separate project. Write and run all tests in a separate Node project using @playwright/test and a dedicated local test origin. The existing playwright-01·02·03 previews only display test source; they do not run Playwright in the iframe. Write new test files yourself for the assignments and judge whether they pass only from actual runner output. Do not use a user profile or storage used for everyday work; preserve CSP and isolation.
The linked example is a starting point. It does not implement every task below. Complete work beyond its supported scope in a separate project.
Practice tasks
- In tests/day-22.spec.ts in a separate practice project, create a fixture that provides test notes and a temporary backup directory. Refer to the existing Unit 1·14·28 examples only as starting points.
- Input conditions: a successful test and a failure partway through. Baseline: normal. Run under the baseline conditions, then record observations and errors in notes/day-22.md.
- Variable: termination; changed value: assertion failure. Run again through the same input path. Deliverable to save: setup and cleanup logs and remaining files. Hypothesis to check: Clean up test resources even after failure. Compare it with the actual results, and record whether they agree and why they differ.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| termination | normal | assertion failure | Clean up test resources even after failure. |
Predictions in this table are not measured results. Change one condition at a time and record why the actual result differs.
Completion criteria
- Required deliverable: setup and cleanup logs and remaining files. Results are available for both the baseline and changed conditions, allowing comparison of 2 conditions; input values and the execution environment are recorded together.
- The explanation of differences between the two conditions connects both concepts: Fixture and Teardown. For unexpected items, at least 1 cause or reason they remain unresolved is recorded.
Self-check
- Which processing stage does Fixture affect in this exercise? Input cases: a successful test and a failure partway through.
- Variable: termination. Hypothesis to check: Clean up test resources even after failure. Did the actual results agree with the hypothesis? Explain the evidence in terms of Teardown.
Official references
- Playwright Installation and Execution
- Playwright Locators
- Playwright Assertions
- Playwright Downloads
- Playwright Visual comparisons
Linked example and execution scope
Example source · Runtime environments and limits
Runnable standalone Playwright spec and HTTP fixture; preview does not run tests.
Source code and records are not overwritten automatically. Resetting an existing example also preserves your notes.
Next learning
Previous: Reading Traces · Next: Parallel Execution and Collisions