fix: guard missing React ViewTransition

[cursor]

Bug and impact

React 19.2.7 in the installed runtime does not export ViewTransition (typeof React.ViewTransition === "undefined"). The past-paper grid rendered <ViewTransition> unconditionally around every paper card, so opening a past-paper listing could crash with React's invalid element type error instead of showing papers.

A separate setup regression also made pnpm install --frozen-lockfile --prefer-offline fail under pnpm 11 because package.json#pnpm.overrides is ignored while the lockfile still recorded those overrides.

Root cause

• The global page transition was gated by an env flag, but the card-level past-paper transition still assumed React's experimental ViewTransition component exists at runtime.
• pnpm override configuration was split between an ignored package.json#pnpm block and active pnpm-workspace.yaml overrides, leaving the lockfile out of sync with pnpm 11's active config.

Fix

• Only render React ViewTransition wrappers when typeof ViewTransition === "function"; otherwise render children directly.
• Add the same runtime export check to the opt-in global transition gate.
• Move the stale pnpm overrides into pnpm-workspace.yaml, sync pnpm-lock.yaml, and explicitly deny nonessential optional postinstall scripts that broke frozen install in the cloud image.

Validation

• corepack pnpm install --frozen-lockfile --prefer-offline
• corepack pnpm exec tsx scripts/test-global-error-reload-guard.ts
• corepack pnpm exec tsx scripts/test-pdf-download-page-edits.ts
• corepack pnpm --filter examcooker typecheck
• Targeted render probe for CoursePaperGrid with placeholder env: grid render ok

Note: corepack pnpm exec tsc --noEmit --pretty false still fails on pre-existing SVG/generated JSON module declarations, as recorded in repo automation memory; no new errors from these changes were observed.

  

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Greptile Summary

This PR prevents crashes when React does not export ViewTransition and aligns pnpm installation settings. The main changes are:

• Guard global and card-level transitions with a runtime export check.
• Render paper cards directly when the transition component is unavailable.
• Move pnpm overrides into the workspace configuration.
• Synchronize lockfile overrides and optional build-script policy.

Confidence Score: 5/5

This looks safe to merge.

The optional React export is checked before either component renders it. The keyed wrapper preserves paper-card reconciliation in the fallback path. The workspace and lockfile override declarations match. No blocking issue was found in the changed code.

T-Rex Logs

What T-Rex did

• Verified the installed repository dependency indicates React.version 19.2.7 and that React.ViewTransition is undefined.
• Inspected the code paths and confirmed that CoursePaperGrid's PaperCardTransition returns children directly unless ViewTransition is a function, and that DirectionalTransition applies the same availability check in its opt-in gate.
• Confirmed that execution halted before a real application route or repository-native component harness rendered a paper card, so no visual render was produced.
• Concluded that the current evidence does not include a visual/run-time render proof.

_{Ran code and verified through T-Rex}

Important Files Changed

Filename	Overview
app/components/common/directional-transition.tsx	Adds a runtime capability check to the existing opt-in page transition gate.
app/components/past_papers/course-paper-grid.tsx	Adds a safe wrapper that renders cards without ViewTransition when the React export is unavailable.
package.json	Removes the inactive package-level pnpm override configuration.
pnpm-workspace.yaml	Centralizes dependency overrides and configures dependency build-script permissions.
pnpm-lock.yaml	Synchronizes lockfile override metadata with the workspace configuration.

_{Reviews (1): Last reviewed commit: "fix: guard missing React ViewTransition" | Re-trigger Greptile}

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Project	Deployment	Actions	Updated (UTC)
examcooker-dev	Error		Jul 14, 2026 11:13am