refactor: use EventType[] in code layer, string only at DB boundary

[shuhuiluo]

• Add DEFAULT_EVENT_TYPES_ARRAY and ALLOWED_EVENT_TYPES_SET constants
• Change SubscribeParams.eventTypes from string to EventType[]
• Update parseEventTypes() to return EventType[] directly
• Update formatEventTypes() to accept EventType[]
• Update isEventTypeMatch() to accept EventType[]
• Extract requiresInstallationFailure() helper to reduce duplication
• Update oauth types to use z.enum(ALLOWED_EVENT_TYPES)
• Convert to/from string only at database boundaries

🤖 Generated with Claude Code

Summary by CodeRabbit

• Refactor

  • Improved type safety and data handling for event subscriptions, yielding more consistent validation and processing.
  • Optimized event-type structures for faster, more reliable filtering.

• Bug Fixes

  • Fixed subscription matching so empty selections behave as match-all and validation is more efficient.

• UI

  • Consistent, properly escaped display of selected event types on OAuth success pages.

• Tests

  • Updated tests to reflect array-based event-type handling.

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

[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

This PR converts event-type handling from comma-separated strings to a typed EventType[] across the codebase. It adds DEFAULT_EVENT_TYPES_ARRAY and ALLOWED_EVENT_TYPES_SET to constants, updates parsing/formatting and validation to use typed arrays and Set lookups, and changes function signatures in handlers and services to accept/return EventType[]. Persistence still stores event types as comma-delimited strings with conversions at storage/retrieval boundaries. Tests and OAuth redirect schema/pages are adjusted to accept and render arrays.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

• Pay attention to conversion points where EventType[] ↔ comma-delimited string for DB persistence (subscription-service).
• Verify signature/API changes and exports in github-subscription-handler, polling-service, and related callers.
• Confirm isEventTypeMatch behavior and EVENT_TYPE_MAP lookups now iterate arrays correctly.
• Validate OAuth schema and redirect handling (types/oauth.ts, routes/oauth-callback.ts) and UI rendering changes in views/oauth-pages.ts.
• Run/update unit tests that were modified to ensure no behavioral regressions.

Possibly related PRs

• refactor: use EventType[] in code layer, string only at DB boundary #67 — Same code-level refactor migrating eventTypes from CSV strings to typed EventType[] across handlers, services, and types.
• feat: add selective event type subscriptions #21 — Refactors and types the selective event-type subscription feature touching handlers, constants, polling/filtering and subscription flows.
• feat: add runtime validation with Zod for GitHub events #23 — Modifies event-type matching/validation logic in polling-service.ts (same surface as this PR).

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately and concisely describes the main refactoring change: introducing EventType[] for type-safe event handling in application code while maintaining string representation only at database boundaries.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

---

📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 673df4d and 6cc3f68.

📒 Files selected for processing (8)

• src/constants.ts (2 hunks)
• src/handlers/github-subscription-handler.ts (6 hunks)
• src/routes/oauth-callback.ts (2 hunks)
• src/services/polling-service.ts (1 hunks)
• src/services/subscription-service.ts (15 hunks)
• src/types/oauth.ts (1 hunks)
• src/views/oauth-pages.ts (4 hunks)
• tests/unit/handlers/github-subscription-handler.test.ts (6 hunks)

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}