feat(#76): bound primary-route fetches and local-first driver summary

Add shared apiFetch timeouts/abort/typed errors with in-flight dedupe, a
RouteState UI for loading/empty/timeout/error+retry, and wire it through
Weekend (Data Health), Championship, Driver Profile, Briefing, Live, and
Race Hub. Driver summary is local-first with bounded optional OpenF1
enrichment so a hung remote call cannot block the profile.

Spike note: parseSourceMode defaults to openf1; driver summary now treats
omitted ?source= as auto so local season data is preferred.

Co-authored-by: Cursor <cursoragent@cursor.com>
This commit is contained in:
2026-07-12 18:00:37 -04:00
parent e8a1f15f8b
commit b3d1730324
29 changed files with 1636 additions and 241 deletions

267
frontend/src/lib/fetch.ts Normal file
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/** Bounded fetch helpers for primary-route resilience. */
export const DEFAULT_FETCH_TIMEOUT_MS = 15_000
export type ApiErrorKind = 'http' | 'timeout' | 'abort' | 'network'
export class ApiError extends Error {
readonly kind: ApiErrorKind
readonly status?: number
readonly stale: boolean
readonly userMessage: string
constructor(
kind: ApiErrorKind,
message: string,
opts?: { status?: number; stale?: boolean; userMessage?: string },
) {
super(message)
this.name = 'ApiError'
this.kind = kind
this.status = opts?.status
this.stale = opts?.stale ?? false
this.userMessage = opts?.userMessage ?? defaultUserMessage(kind, opts?.stale)
}
}
function defaultUserMessage(kind: ApiErrorKind, stale?: boolean): string {
if (stale) {
return 'Showing cached data because a fresh update did not arrive. Retry to refresh.'
}
switch (kind) {
case 'timeout':
return 'This request took too long. Check your connection, then retry.'
case 'abort':
return 'This request was cancelled. Retry when you are ready.'
case 'network':
return 'Could not reach box-box. Check your connection, then retry.'
case 'http':
default:
return 'Something went wrong loading this view. Retry to try again.'
}
}
export function isApiError(err: unknown): err is ApiError {
return err instanceof ApiError
}
export function isTimeoutError(err: unknown): boolean {
return isApiError(err) && err.kind === 'timeout'
}
export function userFacingError(err: unknown): string {
if (isApiError(err)) return err.userMessage
if (err instanceof Error && err.message) {
// Never surface raw "API 500: Internal Server Error" style strings.
if (/^API\s+\d+/i.test(err.message) || /status\s+\d+/i.test(err.message)) {
return defaultUserMessage('http')
}
return err.message
}
return defaultUserMessage('http')
}
export interface ApiFetchOptions {
timeoutMs?: number
signal?: AbortSignal
/** When set, concurrent identical in-flight requests share one promise. */
dedupeKey?: string
method?: string
headers?: HeadersInit
body?: BodyInit | null
}
interface InflightEntry {
/** Shared underlying fetch — not tied to any single caller's AbortSignal. */
promise: Promise<unknown>
/** Aborts the shared request only when the last subscriber cancels. */
controller: AbortController
subscribers: number
}
const inflight = new Map<string, InflightEntry>()
function abortError(): ApiError {
return new ApiError('abort', 'Request aborted', {
userMessage: defaultUserMessage('abort'),
})
}
function combineAbortSignals(signals: AbortSignal[]): AbortSignal {
const controller = new AbortController()
const onAbort = () => {
const reason = signals.find((s) => s.aborted)?.reason
if (!controller.signal.aborted) {
controller.abort(reason)
}
}
for (const signal of signals) {
if (signal.aborted) {
onAbort()
break
}
signal.addEventListener('abort', onAbort, { once: true })
}
return controller.signal
}
async function parseErrorBody(res: Response): Promise<{ error?: string; stale?: boolean }> {
try {
const data = (await res.json()) as { error?: string; stale?: boolean }
return data ?? {}
} catch {
return {}
}
}
async function rawApiFetch<T>(url: string, options: ApiFetchOptions = {}): Promise<T> {
const timeoutMs = options.timeoutMs ?? DEFAULT_FETCH_TIMEOUT_MS
const timeoutController = new AbortController()
const timer = setTimeout(() => {
timeoutController.abort(new DOMException('Request timed out', 'TimeoutError'))
}, timeoutMs)
const signals = [timeoutController.signal]
if (options.signal) signals.push(options.signal)
const signal = combineAbortSignals(signals)
try {
let res: Response
try {
res = await fetch(url, {
method: options.method,
headers: options.headers,
body: options.body,
signal,
})
} catch (err) {
if (timeoutController.signal.aborted && !options.signal?.aborted) {
throw new ApiError('timeout', 'Request timed out', {
userMessage: defaultUserMessage('timeout'),
})
}
if (options.signal?.aborted || (err instanceof DOMException && err.name === 'AbortError')) {
throw abortError()
}
throw new ApiError('network', err instanceof Error ? err.message : 'Network error', {
userMessage: defaultUserMessage('network'),
})
}
if (!res.ok) {
const body = await parseErrorBody(res)
throw new ApiError('http', body.error || `HTTP ${res.status}`, {
status: res.status,
stale: Boolean(body.stale),
userMessage: body.stale
? defaultUserMessage('http', true)
: defaultUserMessage('http'),
})
}
return (await res.json()) as T
} finally {
clearTimeout(timer)
}
}
/**
* Attach a caller to a shared in-flight request.
* One caller's abort rejects only that caller; the shared fetch continues
* while other subscribers remain, and is cancelled only when the last one leaves.
*/
function subscribeToInflight<T>(
key: string,
entry: InflightEntry,
callerSignal?: AbortSignal,
): Promise<T> {
if (callerSignal?.aborted) {
return Promise.reject(abortError())
}
entry.subscribers += 1
return new Promise<T>((resolve, reject) => {
let settled = false
const leave = () => {
entry.subscribers -= 1
if (entry.subscribers <= 0) {
if (!entry.controller.signal.aborted) {
entry.controller.abort()
}
if (inflight.get(key) === entry) {
inflight.delete(key)
}
}
}
const onCallerAbort = () => {
if (settled) return
settled = true
leave()
reject(abortError())
}
if (callerSignal) {
callerSignal.addEventListener('abort', onCallerAbort, { once: true })
}
entry.promise.then(
(value) => {
if (settled) return
settled = true
callerSignal?.removeEventListener('abort', onCallerAbort)
resolve(value as T)
},
(err) => {
if (settled) return
settled = true
callerSignal?.removeEventListener('abort', onCallerAbort)
reject(err)
},
)
})
}
/**
* Fetch JSON with a bounded timeout, abort propagation, typed errors,
* and optional in-flight deduplication (same key shares one underlying request).
*
* Deduped requests are subscriber-safe: aborting one consumer does not cancel
* or poison other consumers that still hold the same key (React Strict Mode remounts).
*/
export function apiFetch<T>(url: string, options: ApiFetchOptions = {}): Promise<T> {
const key = options.dedupeKey
if (!key) {
return rawApiFetch<T>(url, options)
}
if (options.signal?.aborted) {
return Promise.reject(abortError())
}
let entry = inflight.get(key)
if (!entry) {
const controller = new AbortController()
// Shared fetch only listens to the ref-counted controller + timeout —
// never to any single caller's AbortSignal.
const promise = rawApiFetch<T>(url, {
...options,
signal: controller.signal,
}).finally(() => {
if (inflight.get(key)?.promise === promise) {
inflight.delete(key)
}
})
entry = { promise, controller, subscribers: 0 }
inflight.set(key, entry)
}
return subscribeToInflight<T>(key, entry, options.signal)
}
/** Test helper — clears the in-flight dedupe map. */
export function clearApiFetchInflight(): void {
inflight.clear()
}