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Playwright · 14 Saving, Downloading, and Restoring
Series contents · Technology map
Stage: Persistent Data and File Round Trips · Editable example · Storage ID: playwright-02
Goals and learning outcomes
- Learning outcome: explain the role of Round-trip contract. Input cases: empty notes, Korean text, and error files.
- Deliverable: notes after the round trip and error-preservation results. Explain the rationale for handling Isolation, linking it to the code.
Prerequisites
Prepare the experiment results for Identifier and Round trip from Unit 13, “Per-Item Storage Isolation”.
Key concepts and explanations
Round-trip contract
A backup file must be importable to reproduce the same data. Check file creation and storage restoration together.
Isolation
Do not target an origin used for everyday work. Separate files and storage for each test.
Practice setup
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-14.spec.ts in a separate practice project, use a dedicated Frontory test origin. Write the sequence: write notes → download v3 JSON for all 644 units → edit notes → import the same complete file → validation confirmation screen → click the “전체 교체하여 복원” button → reload.
- Input conditions: empty notes, Korean text, and error files. Baseline: valid backup. Run under the baseline conditions, then record observations and errors in notes/day-14.md.
- Variable: file; changed value: invalid JSON. Run again through the same input path. Deliverable to save: notes after the round trip and error-preservation results. Hypothesis to check: Restore a valid file and preserve existing values for an invalid file. Compare it with the actual results, and record whether they agree and why they differ.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| file | valid backup | invalid JSON | Restore a valid file and preserve existing values for an invalid file. |
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: notes after the round trip and error-preservation results. 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: Round-trip contract and Isolation. For unexpected items, at least 1 cause or reason they remain unresolved is recorded.
Self-check
- Which processing stage does Round-trip contract affect in this exercise? Input cases: empty notes, Korean text, and error files.
- Variable: file. Hypothesis to check: Restore a valid file and preserve existing values for an invalid file. Did the actual results agree with the hypothesis? Explain the evidence in terms of Isolation.
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
Source code and records are not overwritten automatically. Resetting an existing example also preserves your notes.
Next learning
Previous: Per-Item Storage Isolation · Next: Keyboard Navigation