fix(inspector): registry query cycle deadlock, error surfacing, and back-navigation

[antfubot]

What & why

Fixes three issues with the web build's Registry Query (Instant) mode.

1. Registry query can silently deadlock on dependency cycles

Some specs (e.g. @nuxt/devtools@4.0.0-alpha.15) never resolved — the resolver froze partway through with the event loop idle and all network requests already completed.

Root cause: in resolveRegistryDependencies, a node's spec was only returned after await-ing its entire subtree expansion. A dependency cycle that revisits the same in-flight name@range therefore produced resolution promises awaiting each other forever.

Fix: decouple node identity from subtree expansion — a node resolves to its spec as soon as its version is picked, and expansion is deferred to a queue drained to a fixpoint by the driver. Cyclic edges back to an in-flight node now resolve immediately. @nuxt/devtools@4.0.0-alpha.15 resolves in a few seconds again.

2. A failed top-level query dropped users into an empty graph

When none of the requested top-level packages could be resolved, the resolver only recorded warnings and still returned a payload, so the app navigated into an empty grid with just a small toast. It now throws in that case, so the landing page shows its "Failed to Resolve Dependencies" error box instead.

3. Landing → inspector didn't create a history entry

Navigating from the landing into the graph used an implicit router.replace, so the browser Back button couldn't return to the landing. The landing now lives at / and pushes into /grid/depth, so Back works. (The landing renders outside <NuxtPage>, where useRoute() returns a stale snapshot — the reactive router.currentRoute is used instead.)

Tests

• New resolver unit tests for 2-/3-node same-range cycles and a self-referential dependency.
• New e2e tests: error-on-landing for an unresolvable query, and Back returns to the landing after a query.
• pnpm test, pnpm typecheck, pnpm lint, and the instant + webcontainer Playwright suites all pass.

This PR was created with the help of an agent.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/node-modules-inspector@200

npm i https://pkg.pr.new/node-modules-tools@200

commit: cc0e68c

[antfu]

isLanding and no errors maybe?

[antfubot]

Good call — guarded the push on isLanding.value && !error.value in cc0e68c so a failed query keeps the user on the landing. (It's inside the try after a successful resolve today, but the explicit !error.value makes the intent clear and is defensive against any non-throwing error path.)