ESLint

@slipher/eslint-plugin is a type-aware ESLint plugin for Seyfert. Every rule resolves symbols through the TypeScript type checker, so it only fires on Seyfert's own Command, Declare, Options, … — never a same-named symbol from elsewhere — and catches mistakes that would otherwise surface as a runtime crash or a Discord 400, as you write.

Installation

The rules are type-aware, so they run on top of typescript-eslint. TypeScript is already part of a Seyfert project, so you only need to add the plugin, ESLint, and the typescript-eslint tooling:

Dependencies...

pnpm add -D @slipher/eslint-plugin eslint typescript-eslint

Configuration

Wire the typescript-eslint parser with type information, then spread the plugin's recommended config into your flat config:

eslint.config.mjs

import tseslint from 'typescript-eslint';
import { configs as seyfert } from '@slipher/eslint-plugin';

export default tseslint.config(
  { languageOptions: { parserOptions: { projectService: true } } },
  ...seyfert.recommended,
);

projectService: true is what gives the rules their type information — without it, the type-aware rules can't run.

Import the named `configs` export

@slipher/eslint-plugin is a CommonJS package. Use the named configs export as shown above — a default import (import seyfert from '@slipher/eslint-plugin') yields the module namespace under ESM interop, not the configs object.

What it catches

configs.recommended turns on these rules as errors:

Rule	Catches
`require-declare`	a command class without `@Declare`
`no-deep-imports`	a `seyfert/lib/...` deep import when the symbol is root-exported (auto-fixable)
`options-use-builders`	a raw object in `@Options({ ... })` instead of a `createXOption` builder
`no-hanging-middleware`	a `createMiddleware` path that never calls `next()` / `stop()`
`decorator-target`	`@Group` on a `SubCommand`, or `@Groups` / `@GroupsT` / `@AutoLoad` on a `Command`
`required-options-order`	a required option declared after an optional one (Discord `400`)
`declare-description`	an empty, or over-100-character, command description
`context-menu-declare`	a `ContextMenuCommand` `@Declare` missing `type`, or carrying a `description`
`autocomplete-respond`	`.reply()` on an autocomplete interaction — it throws; use `.respond()`
`decorator-on-command`	`@Declare` / `@Options` / `@Middlewares` / `@Locales` / `@LocalesT` on a non-command class
`config-default-export`	a `config.bot()` / `config.http()` that isn't the file's `export default`
`i18n-resolve-with-get`	a `ctx.t` locale proxy used as a string without `.get()`
`group-exists`	a subcommand's `@Group('x')` whose group isn't declared on the parent command
`no-method-destructure`	a Seyfert method pulled off its object (`const { editOrReply } = ctx`) — detaching it drops `this` and throws at runtime

Opt-in rules

prefer-typed-group is a best-practice nudge rather than a correctness error, so it isn't in recommended. Turn it on to steer @Group('x') toward the type-validated @Group(groups, 'x') overload:

eslint.config.mjs

export default tseslint.config(
  { languageOptions: { parserOptions: { projectService: true } } },
  ...seyfert.recommended,
  {
    rules: {
      'seyfert/prefer-typed-group': 'warn',
    },
  },
);

Un-awaited responses

By design the plugin has no Seyfert-specific rule for a forgotten await. Enable typescript-eslint's no-floating-promises so an un-awaited ctx.write(...) or ctx.editOrReply(...) is flagged:

eslint.config.mjs

export default tseslint.config(
  { languageOptions: { parserOptions: { projectService: true } } },
  ...seyfert.recommended,
  {
    rules: {
      '@typescript-eslint/no-floating-promises': 'error',
    },
  },
);