build(deps-dev): Bump @sveltejs/kit from 2.43.8 to 2.50.0 (#2716)

[KATO-Hiro]

close #2716

Summary by CodeRabbit

• Chores

  • Upgraded SvelteKit from v2.43.8 to v2.50.0.

• Documentation

  • Added a comprehensive upgrade plan with scope, compatibility notes, phased tasks, verification checklist, observed outcomes, and recommended next steps.

• Tests

  • Updated authentication test to use explicit typing and a UI-driven logout flow; re-ran build and integration checks.

• Known Issues

  • One logout-related test failure/timeout remains for follow-up.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

Walkthrough

SvelteKit devDependency bumped from v2.43.8 to v2.50.0, a new upgrade plan document was added, and a Playwright signin test was updated with typings and a rewritten logout UI flow. No application runtime code changes.

Changes

Cohort / File(s)	Summary
Documentation & Planning docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md	New upgrade plan added: target versions, status/priority, background, breaking-change analysis, features/improvements, phased tasks, verification checklist, install/build/test logs, one failing test noted, and recommended next steps.
Dependencies package.json	Bumped devDependency @sveltejs/kit from 2.43.8 to 2.50.0 (single-line change).
Tests tests/signin.test.ts	Added explicit Playwright Page typings for helpers and rewrote logout to a UI-driven flow (click user button → dropdown logout item → modal confirm). Minor comment/assertion wording edits.

Sequence Diagram(s)

(omitted)

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐰 I hopped through docs and tests today,
Upgraded kit to brighten the way.
I typed my helpers, clicked to sign out,
Logged the build, traced one failing route.
Whiskers twitch—next steps mapped out.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title clearly and specifically describes the main change: bumping @sveltejs/kit dependency version from 2.43.8 to 2.50.0, which matches the primary alteration in package.json.
Linked Issues check	✅ Passed	The PR addresses issue #2716 by upgrading @sveltejs/kit and investigating breaking changes, including fixing the logout flow in tests to accommodate form API specification changes.
Out of Scope Changes check	✅ Passed	The PR includes comprehensive documentation (plan.md) of the upgrade process and detailed test updates related to form API changes, all of which are necessary and directly related to the SvelteKit upgrade and investigation objectives.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md`:
- Line 284: Update the date in the verification checklist row that reads "pnpm
install（2025-01-18）" to "2026-01-18" so it matches the document header; locate
the table row containing "パッケージインストール" and replace the year 2025 with 2026 in
the timestamp.
- Around line 244-270: The logout E2E test fails because signin.test.ts cannot
find the navbar user link (getByRole('link', { name: 'guest' })) after the
SvelteKit upgrade; fix this by making the navbar render an accessible link with
the same role/name or by updating the test to match the new markup: inspect the
Navbar component to ensure the username is rendered as a semantic <a> (or
element with role="link") and its accessible name equals "guest" when signed in,
ensure any dropdown is programmatically visible (or expose the trigger) before
clicking in the logout test, and update signin.test.ts (the locator using
getByRole('link', { name: 'guest' })) only if the UI intentionally changed
(prefer fixing the component to preserve accessibility and existing test
behavior).

🧹 Nitpick comments (1)

docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md (1)

255-260: Add language specifiers to fenced code blocks.

Several code blocks containing command output are missing language specifiers. Consider adding text or plaintext to satisfy markdown linting rules.

Example fix for one block (apply similar pattern to others)

-```
+```text
 Test timeout of 30000ms exceeded.
 Error: locator.click: Test timeout of 30000ms exceeded.

Also applies to: 334-342, 346-355, 359-378

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md`:
- Around line 7-9: Update the document’s status so it accurately reflects the
unresolved failing logout E2E test: replace or qualify the current "ステータス: ✅
アップグレード完了（2026-01-18 実施）" with a status like "部分的完了（保留事項あり）" or "アップグレード実施 —
調査中のE2E失敗あり", and add a short note next to the failing "logout" test entry
indicating it's under investigation and blocking full completion; apply the same
change to the other occurrences called out (sections around the lines noted) so
all instances consistently reflect the unresolved test.

🧹 Nitpick comments (1)

docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md (1)

334-342: Specify languages for fenced code blocks.

Markdownlint flags these blocks because the fences have no language. Add bash or terminal to keep docs lint-clean.

Also applies to: 346-355, 359-378

[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md`:
- Around line 263-266: Replace the bold-only line "**調査完了 ✅**" with a proper
markdown heading to satisfy markdownlint MD036; e.g., change that line to a
heading such as "##### 調査完了 ✅" so the file
docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md uses
a heading token instead of bold-only text.
- Around line 423-431: The fenced code blocks in plan.md are missing language
identifiers (MD040) — update each triple-backtick fence shown (the block at the
example and the other blocks referenced around lines 435-441 and 448-459) to
include an appropriate language tag such as bash for shell output or text for
generic output (e.g., replace ``` with ```bash or ```text) so markdownlint MD040
is satisfied; ensure all similar fences in this document use consistent,
appropriate language tags.

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md`:
- Around line 464-466: Remove the outdated recommended action "logout テストの修正:
navbar ユーザーリンク取得の調査" from the "推奨アクション（次フェーズ）" list because the document already
marks that work complete (references show 実装完了 and 18/18 パス); update the section
to reflect current outstanding actions only and, if needed, replace with any
remaining real follow-ups or delete the empty list item so the document no
longer contradicts its status.

🧹 Nitpick comments (1)

docs/dev-notes/2026-01-18/bump-sveltejs-kit-from-v2.43.8-to-v2.50.0/plan.md (1)

265-265: Consider using a proper heading instead of bold text.

The markdownlint tool flags this line for using bold emphasis instead of a proper heading structure. While this is a minor formatting issue, using a heading (e.g., ##### 調査完了 ✅) would improve document structure and consistency.

Proposed fix

-**調査完了 ✅**
+##### 調査完了 ✅

[KATO-Hiro]

LGTM