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feat(core): surface mid-session transport failures via lastError (#1489)

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Closes #1323. Adds an `error`-event-driven `lastError` on useInspectorClient and a mid-session failure toast in App.tsx; the transport onerror is scoped to non-handshake (status !== connecting) so handshake failures stay on the connect() rejection path. Follow-up: #1490.
This commit is contained in:
Cliff Hall 2026-06-15 08:46:59 -04:00 • committed by GitHub
commit b4716a1405
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1 changed files with 398 additions and 7 deletions
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22
core/react/useInspectorClient.ts
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@ -22,6 +22,14 @@ export interface UseInspectorClientResult {
serverInfo?: Implementation;
instructions?: string;
protocolVersion?: string;
/**
* Message from the most recent mid-session transport failure (the client's
* `error` event — stdio crash, SSE drop, HTTP 5xx). Stays set until the next
* connection attempt (`status` → `"connecting"`) clears it, so consumers can
* render it without subscribing to the event directly. Handshake failures do
* NOT populate this — they reject the `connect()` promise instead.
*/
lastError?: string;
appRendererClient: AppRendererClient | null;
connect: () => Promise<void>;
disconnect: () => Promise<void>;
@ -58,6 +66,7 @@ export function useInspectorClient(
const [protocolVersion, setProtocolVersion] = useState<string | undefined>(
inspectorClient?.getProtocolVersion(),
);
const [lastError, setLastError] = useState<string | undefined>(undefined);
useEffect(() => {
if (!inspectorClient) {
@ -66,6 +75,7 @@ export function useInspectorClient(
setServerInfo(undefined);
setInstructions(undefined);
setProtocolVersion(undefined);
setLastError(undefined);
return;
}
@ -74,9 +84,18 @@ export function useInspectorClient(
setServerInfo(inspectorClient.getServerInfo());
setInstructions(inspectorClient.getInstructions());
setProtocolVersion(inspectorClient.getProtocolVersion());
setLastError(undefined);
const onStatusChange = (event: TypedEvent<"statusChange">) => {
setStatus(event.detail);
// A fresh connection attempt clears any stale error from the prior
// session so the UI doesn't keep showing why the last transport died.
if (event.detail === "connecting") {
setLastError(undefined);
}
};
const onError = (event: TypedEvent<"error">) => {
setLastError(event.detail.message);
};
const onCapabilitiesChange = (event: TypedEvent<"capabilitiesChange">) => {
setCapabilities(event.detail);
@ -94,6 +113,7 @@ export function useInspectorClient(
};
inspectorClient.addEventListener("statusChange", onStatusChange);
inspectorClient.addEventListener("error", onError);
inspectorClient.addEventListener(
"capabilitiesChange",
onCapabilitiesChange,
@ -110,6 +130,7 @@ export function useInspectorClient(
return () => {
inspectorClient.removeEventListener("statusChange", onStatusChange);
inspectorClient.removeEventListener("error", onError);
inspectorClient.removeEventListener(
"capabilitiesChange",
onCapabilitiesChange,
@ -152,6 +173,7 @@ export function useInspectorClient(
serverInfo,
instructions,
protocolVersion,
lastError,
appRendererClient: inspectorClient?.getAppRendererClient() ?? null,
connect,
disconnect,