Nonblocking plugin install status projection

SKILL: Nonblocking Plugin Install Status Projection

Domain: extensions-mcp
Trigger: Use when marketplace reconciliation emits progress events but the main UI must remain responsive with up-to-date status rows. Source Pattern: Distilled from reviewed extension lifecycle and source-reconciliation patterns.

Core Method

Before the async reconciliation runs, seed AppState with pending rows for every diffed marketplace. Pass a shared updater into the reconciler’s onProgress hook that maps each event type (installing, installed, failed) to the corresponding AppState entry by marketplace name, keeping the rest of the state untouched. When an event includes an error, annotate that marketplace row so the UI can reveal diagnostics while still letting other installers continue running.

Key Rules

• Always update AppState immutably via setAppState(prev => ({ ...prev, plugins: { ...prev.plugins, installationStatus: { ... }}})) to avoid clobbering unrelated UI state.
• Use a central helper like updateMarketplaceStatus so each event only updates the matching marketplaces entry (by name) and nothing else.
• Include event-specific metadata (status, optional error) in the row so the UI can show spinners, success checks, or failure hints.
• Keep this projection logic outside the main reconciling flow so the long-running reconcileMarketplaces call never awaits UI updates; it merely fires events.

Example Application

If your agent tracks multiple plugin sources, apply this skill to emit nonblocking status rows for each install progress report so the user can monitor clones without stalling the command loop.

Anti-Patterns (What NOT to do)

• Do not mutate the AppState array in place or replace installationStatus wholesale; that would drop other concurrent progress rows.
• Do not ignore the error payload on failures, or the UI will never explain why a marketplace install failed.
• Avoid waiting for the entire reconciliation to finish before updating statuses; the whole point is incremental feedback.