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Playwright · 05 Locator Scope
Series contents · Technology map
Stage: User Flows and Locators · External example · preview instructions · Storage ID: playwright-step-05
Goals and learning outcomes
- Learning outcome: explain the role of Narrowing scope. Input cases: three cards with the same button name.
- Deliverable: selected card ID and title. Explain the rationale for handling Strictness, linking it to the code.
Prerequisites
Prepare the experiment results for Label and Value assertion from Unit 4, “Label and Input”.
Key concepts and explanations
Narrowing scope
Finding a button within a list item distinguishes duplicate names. Do not depend on the first button on the entire page.
Strictness
An error caused by multiple matches reveals an ambiguous contract. Find the item’s meaning before hiding the issue with nth.
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-5.spec.ts in a separate practice project, filter the card locator by title, then click its internal button. Refer to the existing Unit 1·14·28 examples only as starting points.
- Input conditions: three cards with the same button name. Baseline: original order. Run under the baseline conditions, then record observations and errors in notes/day-5.md.
- Variable: list order; changed value: reverse order. Run again through the same input path. Deliverable to save: selected card ID and title. Hypothesis to check: Operate on the same card even when the order changes. Compare it with the actual results, and record whether they agree and why they differ.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| list order | original order | reverse order | Operate on the same card even when the order changes. |
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: selected card ID and title. 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: Narrowing scope and Strictness. For unexpected items, at least 1 cause or reason they remain unresolved is recorded.
Self-check
- Which processing stage does Narrowing scope affect in this exercise? Input cases: three cards with the same button name.
- Variable: list order. Hypothesis to check: Operate on the same card even when the order changes. Did the actual results agree with the hypothesis? Explain the evidence in terms of Strictness.
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.