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Playwright · 13 Per-Item Storage Isolation
Series contents · Technology map
Stage: Persistent Data and File Round Trips · External example · preview instructions · Storage ID: playwright-step-13
Goals and learning outcomes
- Learning outcome: explain the role of Identifier. Input cases: note A and note B.
- Deliverable: mapping table of input and restored values for each item. Explain the rationale for handling Round trip, linking it to the code.
Prerequisites
Prepare the experiment results for Validation failure and Negative path from Unit 12, “Invalid Files and Preservation”.
Key concepts and explanations
Identifier
Notes are associated with learning unit IDs. Storing by title or array position may mix items.
Round trip
Visit another item and return to check isolation. Testing only one item misses this check.
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-13.spec.ts in a separate practice project, enter different notes in two learning units and alternate between them. Refer to the existing Unit 1·14·28 examples only as starting points.
- Input conditions: note A and note B. Baseline: A→B. Run under the baseline conditions, then record observations and errors in notes/day-13.md.
- Variable: navigation; changed value: A→B→A. Run again through the same input path. Deliverable to save: mapping table of input and restored values for each item. Hypothesis to check: Display each note only in its own unit. Compare it with the actual results, and record whether they agree and why they differ.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| navigation | A→B | A→B→A | Display each note only in its own unit. |
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: mapping table of input and restored values for each item. 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: Identifier and Round trip. For unexpected items, at least 1 cause or reason they remain unresolved is recorded.
Self-check
- Which processing stage does Identifier affect in this exercise? Input cases: note A and note B.
- Variable: navigation. Hypothesis to check: Display each note only in its own unit. Did the actual results agree with the hypothesis? Explain the evidence in terms of Round trip.
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: Invalid Files and Preservation · Next: Saving, Downloading, and Restoring