Inline error handlers

Register function handlers on host.http.error or g.error inside a route group.

Overloads

Overload	Signature
Function	.error(HttpErrorHandler)
Function + options	.error(HttpErrorHandlerOptions, HttpErrorHandler)

import { FlareError, FlareHost, FlareResponse } from "@flare-ts/core";
import { flareErrorCodes } from "@flare-ts/core/errors";
import { node } from "@flare-ts/core/node";

const UserErrors = flareErrorCodes({
  not_found: {
    UserNotFound: { expose: true, code: 1001 },
  },
});

const host = new FlareHost(node);

host.http.error((err, context) => {
  if (err instanceof FlareError && err.category === "not_found") {
    return new FlareResponse(404, {
      error: err.name,
      requestId: context.requestId,
    });
  }
});

host.http.get("/users/missing", () => {
  throw new FlareError(UserErrors.not_found.UserNotFound);
});

const app = host.build();
app.run();

Handler signature

(err, context, scope) => ResponseLike | void | Promise<...>

Argument	Type	Notes
err	FlareError | Error	The thrown value
context	HttpErrorContext	requestId, method, url, optional stage / target
scope	HandlerScope	inject map entries and scope.config

There is no ctx.state on error handlers. Pass data through FlareError.detail or an injected service.

HttpErrorHandlerOptions

Option	Purpose
inject	Named map { name: Token } for scope.name
name	Display name for the generated wrapper

import { FlareHost, FlareResponse, Logger } from "@flare-ts/core";
import { node } from "@flare-ts/core/node";

const host = new FlareHost(node);

host.http.error({ inject: { log: Logger } }, (err, context, scope) => {
  scope.log.error(err, "unhandled", { requestId: context.requestId });
  return new FlareResponse(500, { error: "Internal Server Error" });
});

const app = host.build();
app.run();

Related

• ErrorHandlerBase classes
• Register a custom handler