Handling Errors

With Seyfert, you can handle errors in an organized way and treat them differently depending on the type of error.

Error when executing a command

This is the most common error and occurs when an error is thrown in the run method.

import { Command, type CommandContext } from "seyfert";
 
export class HandlingErrors extends Command {
  async run(context: CommandContext) {
    throw new Error("Error, ehm, lol player detected");
  }
 
// : This responds with the previous error message: "Error, ehm, lol player detected"
  async onRunError(context: CommandContext, error: unknown) {
    context.client.logger.fatal(error);
    await context.editOrReply({
      content: error instanceof Error ? error.message : `Error: ${error}`
    });
  }
}

Error when validating options

This error is thrown when an option fails in the value method.

const options = {
  url: createStringOption({
    description: 'how to be a gamer',
    value(data, ok: OKFunction<URL>, fail) {
        if (isURL(data.value)) return ok(new URL(data.value));
 
// This will trigger the onOptionsError method
        fail('expected a valid URL');
    },
  })
};
 
@Options(options)
export class HandlingErrors extends Command {
    async onOptionsError(
        context: CommandContext,
        metadata: OnOptionsReturnObject
    ) {
// : url: expected a valid URL
    await context.editOrReply({
      content: Object.entries(metadata)
        .filter((_) => _[1].failed)
        .map((error) => `${error[0]}: ${error[1].value}`)
        .join("\n")
    });
  }
}

Stop a middleware with an error

When a middleware returns a stop, Seyfert generates this error and stops the progress of the command being handled.

import { createMiddleware } from "seyfert";
 
export default createMiddleware<void>(({ context, next, stop, pass }) => {
    if (!Devs.includes(context.author.id)) {
        return stop("User is not a developer");
    }
    next();
});

import { Command, Middlewares, type CommandContext } from "seyfert";
 
@Middlewares(["OnlyDev"])
export class HandlingErrors extends Command {
    async onMiddlewaresError(context: CommandContext, error: string) {
        await context.editOrReply({
// : User is not a developer
            content: error
        });
    }
}

Although Seyfert provides a way to handle errors, you can do it in the way that best suits your needs (we recommend the way we showed, lol).

Handling Errors

Error when executing a command

Error when validating options

Stop a middleware with an error

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