feat(test): add captureScreenshot helper to test/screenshots.ts

[nicomiguelino]

Summary

• Adds captureScreenshot(browser, options) to src/test/screenshots.ts, where options: CaptureScreenshotOptions is { width, height, filenamePrefix, screenlyJsContent, setupMocks? }. Consolidates the browser/page setup, clock + screenly.js mocking, navigation, and screenshot capture boilerplate that's currently duplicated across Edge App e2e specs (rss-reader-app, Playground's simple-table-app, etc.).
  • Uses an options object rather than the positional-args signature originally proposed in feat: add runScreenshotTests helper to test/screenshots.ts #27, to avoid transposing adjacent same-typed string args (filenamePrefix, screenlyJsContent) at call sites — cheap to change pre-release, before any consumer depends on the exact shape.
  • setupMocks is optional (defaults to a no-op) for callers with nothing app-specific to mock.
• test() calls stay in the spec files (not wrapped by the helper) so Playwright still reports the correct source location.
• Updates the scripts/create-template/e2e/screenshots.spec.ts scaffold (used by create-scaffold.js to bootstrap new Edge Apps in this repo) to use the new helper.
• Documents captureScreenshot in README.md under a new "Screenshot Testing" subsection.
• Bumps the package version to 26.8.0, adopting Calendar Versioning (YY.M.PATCH) per docs(contributing): switch to Calendar Versioning #76 — this is the first release under the new scheme for August 2026.

DEPENDS ON #76 being merged first, since that PR documents the versioning scheme this release follows.

NOTE: existing Edge App repos (rss-reader-app, Playground, etc.) still contain the duplicated boilerplate this helper replaces. Those will be migrated manually in follow-up PRs, not as part of this change.

Closes #27

[Copilot]

Pull request overview

Introduces a reusable captureScreenshot(...) helper in the test utilities to centralize the common Playwright setup/mocking/navigation/screenshot steps used by Edge App screenshot specs, updates the e2e template scaffold to use it, and bumps the package version to the first Calendar Versioning release.

Changes:

• Add captureScreenshot helper to src/test/screenshots.ts for consistent screenshot test setup and capture.
• Update the scripts/create-template e2e screenshot spec scaffold to call the new helper.
• Bump package version to 26.8.0 (Calendar Versioning) and sync package-lock.json.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/test/screenshots.ts	Adds Playwright-shaped interfaces and the new captureScreenshot helper.
scripts/create-template/e2e/screenshots.spec.ts	Replaces duplicated boilerplate with captureScreenshot(...) usage in the scaffold.
package.json	Updates version to 26.8.0.
package-lock.json	Updates lockfile package versions to 26.8.0.

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[nicomiguelino]

Good catch — fixed in e0aa483 by wrapping the body in try/finally so context.close() always runs.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 4 changed files in this pull request and generated no new comments.

Suppressed comments (2)

Previously missed (2) — in code that hasn't changed since the last review.

src/test/screenshots.ts:38

• PlaywrightPage.route forces route handlers to return Promise<void>, but Playwright allows synchronous handlers too. This makes common page.route(..., route => { ... }) patterns fail type-checking for consumers of captureScreenshot.

  route(
    url: string,
    handler: (route: PlaywrightRoute) => Promise<void>,
  ): Promise<void>

src/test/screenshots.ts:248

• setupMocks is typed as (page: PlaywrightPage) => Promise<void>. With strict: true, callers cannot annotate the callback parameter as Playwright’s real Page type (it becomes too specific under strictFunctionTypes), which makes it hard to use the full Page API without casts. Consider making this callback bivariant so callers can type it as Page when they have Playwright types available.

  setupMocks: (page: PlaywrightPage) => Promise<void>,

[Copilot]

Pull request overview

Copilot reviewed 4 out of 5 changed files in this pull request and generated 2 comments.

Suppressed comments (1)

src/test/screenshots.ts:263

• captureScreenshot call sites with no app-specific mocks currently have to pass a no-op setupMocks. If setupMocks is made optional, default it in the destructuring to keep the implementation simple and avoid extra checks.

    filenamePrefix,
    screenlyJsContent,
    setupMocks,
  }: CaptureScreenshotOptions,
): Promise<void> {

[Copilot]

Pull request overview

Copilot reviewed 4 out of 5 changed files in this pull request and generated no new comments.

Suppressed comments (1)

Previously missed (1) — in code that hasn't changed since the last review.

src/test/screenshots.ts:263

• The PR description (and linked issue) describe captureScreenshot(browser, width, height, filenamePrefix, screenlyJsContent, setupMocks) as a positional-args API, but the implementation here uses an options object. Please align the public API story by either updating the PR description/docs to reflect the options shape, or adding a positional-args overload/wrapper for the described signature (so consumers can follow the docs verbatim).

export async function captureScreenshot(
  browser: PlaywrightBrowser,
  {
    width,
    height,
    filenamePrefix,
    screenlyJsContent,
    setupMocks = async () => {},
  }: CaptureScreenshotOptions,
): Promise<void> {