catfishing

A fishing game discord bot for the Ninajirachi server that uses cats instead of fish

Prerequisites

Install mise.

Project Structure

Layer	Tool
Runtime	Node.js ≥22.12, ESM
Language	TypeScript ~6.0
Bot framework	discord.js v14
Env var management	@t3-oss/env-core + zod
Logging	pino (pretty in dev, JSON in prod)
Dev runner	tsx
Bundler	rolldown
Linter	oxlint
Formatter	oxfmt
Tests	vitest
Toolchain manager	mise

File Structure

Path	Description
src/	All bot source code
src/commands/	Slash command implementations
src/events/	Discord event handlers
src/lib/	Shared game logic
src/util/	Infrastructure (env, logging, formatting)
.env.example	Template for required environment variables
mise.toml	Node.js version + pnpm toolchain config
tsconfig.json	TypeScript config
oxlint.config.ts	Linter rules
oxfmt.config.ts	Formatter config
rolldown.config.ts	Bundler config

Setup

mise install        # installs Node.js and pnpm
pnpm install        # installs dependencies
cp .env.example .env

Edit .env and fill in:

Variable	Description
DISCORD_TOKEN	Bot authentication token
APPLICATION_ID	Discord application ID
GUILD_ID	Server ID for the bot to register commands in

Development

pnpm dev

Runs the bot locally using tsx (no build step required). This uses watch mode, so any source code changes should trigger an automatic restart of the bot. Note that mise will auto-load .env.

Build

pnpm build

Bundles to dist/index.js via rolldown.

Other scripts

Command	Description
pnpm run lint	Lint with oxlint
pnpm run lint:fix	Auto-fix lint issues
pnpm run format	Apply formatting
pnpm run format:check	Check formatting
pnpm run typecheck	Type-check without emitting
pnpm run test	Run tests with vitest

Development Practices

Environment Variables

When using an environment variable, add it to util/env.ts and then import this module. This validates it at bot startup via zod, which will exit the bot with a clear error if any environment variables are malformed or missing.

Adding a Command

Create a new file in src/commands/ and export an object satisfying the Command interface.

export default {
  data: { name: "mycommand", description: "Does something." },
  async execute(interaction, ctx) {
    // your logic here
  },
} satisfies Command;

Then import and add it to cmdList in commands/index.ts. Commands are guild registered on bot startup, so they will be available in Discord immediately upon next bot run (or after the bot automatically restarts via watch mode if using pnpm dev).

If your command hits an unrecoverable error, throw an exception. The interaction handler catches it and sends an ephemeral error reply automatically.

Logging

The bot uses pino for logging. Import the shared logger from util/logger.ts, and scope it to your command with .child() so log output is easy to filter.

const log = ctx.logger.child({ command: "mycommand" });
log.info("doing a thing");
log.debug({ userId: interaction.user.id }, "user invoked command");

In development, the output is human-readable via pino-pretty. In production (when NODE_ENV=production is set) it emits JSON. You can override the log level at any time by setting LOG_LEVEL in your .env (e.g. LOG_LEVEL=debug).