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Playwright · 06 Retrying Assertions
Series contents · Technology map
Stage: User Flows and Locators · External example · preview instructions · Storage ID: playwright-step-06
Goals and learning outcomes
- Learning outcome: explain the role of Waiting for state. Input cases: fast and delayed responses.
- Deliverable: assertion success and failure messages. Explain the rationale for handling Failure explanation, linking it to the code.
Prerequisites
Prepare the experiment results for Narrowing scope and Strictness from Unit 5, “Locator Scope”.
Key concepts and explanations
Waiting for state
Assertions such as toBeVisible reevaluate the condition. Their waiting behavior differs from ordinary value comparisons.
Failure explanation
A clear expected state makes timeout diagnosis easier. An unconditionally long timeout does not solve the root cause.
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-6.spec.ts in a separate practice project, combine expect(dialog).toBeVisible and a title assertion after opening the document. Refer to the existing Unit 1·14·28 examples only as starting points.
- Input conditions: fast and delayed responses. Baseline: none. Run under the baseline conditions, then record observations and errors in notes/day-6.md.
- Variable: delay; changed value: controlled short delay. Run again through the same input path. Deliverable to save: assertion success and failure messages. Hypothesis to check: Wait for readiness without a fixed sleep. Compare it with the actual results, and record whether they agree and why they differ.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| delay | none | controlled short delay | Wait for readiness without a fixed sleep. |
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: assertion success and failure messages. 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: Waiting for state and Failure explanation. For unexpected items, at least 1 cause or reason they remain unresolved is recorded.
Self-check
- Which processing stage does Waiting for state affect in this exercise? Input cases: fast and delayed responses.
- Variable: delay. Hypothesis to check: Wait for readiness without a fixed sleep. Did the actual results agree with the hypothesis? Explain the evidence in terms of Failure explanation.
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: Locator Scope · Next: Diagnosing Failures in the First Flow