solidjs-v2-reviewer

name	solidjs-v2-reviewer
description	Review SolidJS 2.0 code for React-isms, Solid 1.x-isms, and reactivity bugs. Use when reviewing diffs, PRs, or files in a project that depends on solid-js 2.x / @solidjs/web — including self-review after generating Solid 2.0 code.

Review Solid 2.0 code

Hunt the two prior-knowledge bug classes — React reflexes and Solid 1.x reflexes — plus 2.0-specific reactivity mistakes. Severity guide: 🔴 broken behavior, 🟡 dev-mode diagnostic / lost reactivity, 🔵 style drift.

Confirm the project is actually v2 first (solid-js major 2 in package.json / @solidjs/web in deps). Reviewing a 1.x project against this list produces garbage findings.

Pass 1 — greppable smells

Run these over the changed files; each hit needs a fix or a justification.

Solid 1.x-isms

Grep	Verdict	Fix
from ['"]solid-js/(web|store|h|html|universal)	🔴 module not found	@solidjs/web, store APIs from solid-js, @solidjs/h…
createResource|useTransition|startTransition	🔴 removed	async memo + <Loading>; built-in transitions / isPending
\bbatch\s*\(	🔴 removed	delete wrapper; flush() only for sync read-after-write
createComputed|createMutable|modifyMutable|createDeferred	🔴 removed	memo / split effect / createSignal(fn); createStore drafts
\bon\s*\( as effect dep helper, onMount|onError|catchError	🔴 removed	split effect compute; onSettled; <Errored> / effect error
<Suspense|<SuspenseList|<ErrorBoundary|<Index\b	🔴 removed	<Loading> / <Reveal> / <Errored> / <For keyed={false}>
mergeProps|splitProps|unwrap\s*\(|createSelector	🔴 removed	merge / omit / snapshot / createProjection
\.Provider\b	🔴 removed	<Ctx value={...}> — context is the provider
classList=	🔴 removed	class={{...}} / class={[...]}
use:[a-zA-Z]|attr:|bool:|on:[a-z]|oncapture: in JSX	🔴 removed	ref factories; standard attributes; onClick + ref for native opts
produce\s*\( in setters	🟡 redundant	drafts are the default
setStore\s*\(\s*["'] (path-style first arg)	🔴 wrong API	draft setter or storePath(...)
/\*@once\*/	🟡 ignored marker	reactive read / defaultValue / untrack
\.loading\b|\.error\b on async values	🔴 no such props	isPending(() => x()) / <Errored>

React-isms

Grep / pattern	Verdict	Fix
function \w+\(\s*\{ (destructured props)	🟡 reactivity dead + warns	props.x access
useState|useEffect|useMemo|useRef|useCallback	🔴 wrong framework	Solid primitives
<X value={count} /> passing an accessor where a value is expected	🔴 child gets a function	value={count()} — collapse at the JSX boundary
key= prop on list items	🟡 no-op	<For keyed={...}> modes
className|`${...}`/.join(" ") class building	🔵 reflex	class array/object form
deps-array thinking: effect re-created per "render"	🟡 model error	components run once; compute phase = deps

2.0-specific

Pattern	Verdict	Fix
Single-callback createEffect(fn)	🔴 throws	split (compute, apply)
createEffect(fn, 0) / createMemo(fn, 0) initial values	🔴 wrong arg	options object; prev default parameter
Setter then immediate read of same signal/DOM	🔴 stale read	flush() or restructure
Signal/store write inside memo/compute/component body	🔴 throws in dev	derive, or move write to handler/action
actionFn() invoked inside memo/compute/component body	🔴 dev error (ACTION_CALLED_IN_OWNED_SCOPE, beta.17); may livelock in prod	invoke from handler/effect callback/onSettled
ownedWrite: true on app state	🟡 escape-hatch abuse	derive instead; ownedWrite is for internal flags
Top-level const x = props.x / store read in component body	🟡 warns, stale	read in JSX/memo; untrack if deliberate
onCleanup inside onSettled/createTrackedEffect	🔴 throws	return cleanup
Cleanup returned from onSettled fired out of band (event handler/tracked effect/nested onSettled)	🔴 dev error (beta.16), dropped in prod	call the setup helper from the component body (owned scope)
Primitives created inside onSettled/tracked effect	🔴 throws	create in component body
Store proxy passed compute→apply, read in apply	🟡 warns, won't re-run	extract plain values / deep(store) in compute
Async read with no <Loading> ancestor	🟡 root mount deferred	add boundary where fallback UI is wanted
async function* memo over a socket/emitter/observable with no up-front onCleanup	🔴 leaks on dispose/re-run	onCleanup (before the first await/yield) that cancels the source; try/finally/.return() can't unwind a parked generator
refresh() called inside a computation	🔴 throws	call from handlers/actions
isRefreshing( call (or imported from solid-js)	🔴 removed in beta.15	gone from solid-js exports; detect a refresh re-run by key comparison, or use isPending/<Loading>
<For> callback shape vs keying mode mismatch (item() on keyed, i() on keyed={false})	🔴 type/runtime error	check the mode table
Dynamic boolean keyed={cond()} with function children	🟡 ambiguous shape	literal mode or key function
useX-with-throw context wrapper hooks	🔵 dead boilerplate	direct useContext (throws by itself)
camelCase DOM attributes (tabIndex, readOnly)	🟡 wrong attribute	lowercase; handlers stay camelCase
merge(..., maybeUndefined) assuming skip semantics	🔴 silently overrides	filter keys or restructure defaults

Pass 2 — judgement checks (not greppable)

• Derive vs write-back: any effect whose apply phase sets reactive state is suspect — usually a memo/projection in disguise.
• Boundary ownership: isPending reads placed under the Loading boundary that owns the data read? Pending indicators outside can never fire.
• Mutation shape: server writes wrapped in action() with optimistic state and a final refresh()? Ad-hoc async handlers flipping flags are the 1.x smell in new clothes.
• Action call site: an action may be defined in a component, but is it invoked only from an imperative scope? A component-body/computation call is a transaction-starting write and throws in beta.17 dev mode.
• Optimistic spinner off isPending: a "Saving…" indicator driven by isPending on data the same action just wrote optimistically can never show — an active optimistic write masks isPending store-wide (beta.16). The flag belongs in the data (co-written pending: true or a separate createOptimistic(false)).
• Granularity: selection/derived caches notifying whole collections → createProjection. Fixed-slot lists diffed with <For> → <Repeat>.
• Ownership: module-scope effects/roots intentional? Detached lifetime must be explicit (runWithOwner(null, ...)).
• Composable naming: a createX/useX prefix should match lifecycle, not React habit — createX makes a fresh instance owned by the caller, useX is a shared singleton or accesses an already-created thing (useContext). useX is not wrong by itself (singletons are legit); flag only a per-call instance named useX, or every composable defaulting to useX out of reflex.
• Layout lane: DOM-geometry reads (getBoundingClientRect/offset*) belong in a createRenderEffect (render lane), not in a ref callback (node may be pre-insert/pre-layout there). Beware the inverse "fix" too: moving a layout measure out of createRenderEffect into createEffect/a ref on the false theory that render effects read a disconnected node — they don't; the trigger is flush-scheduled and runs after insertion.
• Tests: flush() after writes; createRoot wrappers; resolve() for async settling.

Reporting

Report findings ordered by severity with file:line, the broken expectation (one line), and the concrete 2.0 fix. Note clean areas that were checked. For deep API verification during review, the solidjs-v2 skill's references cover signatures; installed typings in node_modules are final word — the betas churn the public API freely (e.g. isRefreshing was a public solid-js export from beta.0 through beta.14, then removed in beta.15).