Error reports with context

Errors that the code catches

In a catch block, the context of the operation is current (rule C3). Read the context and add it to the report:

try {
    await traced("save", () => saveDocument(draft));
} catch (error) {
    report(error, { trace : traceStorage.getStore() });
}

The catch block above is outside traced(), so it gets the outer context. Put the try statement inside the function of traced() to get the trace of the action.

Errors that the code does not catch

A window.onerror handler or an unhandledrejection listener gets its registration context (rule C13), because the browser dispatches the event. The registration context is usually the root context. Thus, record the context in the error object before the error leaves the operation:

const CONTEXT = Symbol("context");

export function traced<R>(action : string, fn : () => Promise<R>) : Promise<R> {
    return traceStorage.run({ traceId : crypto.randomUUID(), action }, async () => {
        try {
            return await fn();
        } catch (error) {
            if (typeof error === "object" && error !== null) {
                Object.defineProperty(error, CONTEXT, { value : traceStorage.getStore() });
            }
            throw error;
        }
    });
}

window.addEventListener("unhandledrejection", (event) => {
    const reason : unknown = event.reason;
    const trace = typeof reason === "object" && reason !== null ? (reason as Record<symbol, unknown>)[CONTEXT] : undefined;
    report(reason, { trace });
});