Eamon Hyland's Preferences

Category	Preference
Package Manager	Bun for apps, pnpm for libraries
Language	TypeScript (strict mode, ESM only)
Linting & Formatting	Oxlint and Oxfmt
Testing	Bun for apps, Vitest for libraries
Git Hooks	simple-git-hooks + lint-staged
Bundler	Bun for apps, tsdown for libraries

Core Conventions

Server environment configuration

•Server configuration should be loaded from environment variables and validated with zod
•Default values should be set for dev environment
•Test defaults can be set in the test runner (e.g. bun test or vitest setup script)

Configuration should be defined in src/config.ts or src/server/config.ts (for fullstack apps)

// src/config.ts
import { z } from "zod";

const configSchema = z.object({
  PORT: z.coerce.number().default(3000),
  NODE_ENV: z.enum(["development", "production", "test"]).default("development"),
  DATABASE_URL: z.string().default("sqlite.db"),
});

const parsed = configSchema.safeParse(process.env);

if (!parsed.success) {
  console.error("❌ Invalid environment variables:", parsed.error.flatten().fieldErrors);
  process.exit(1);
}

export const config = parsed.data

// src/config.ts
import { z } from "zod";

const configSchema = z.object({
  PORT: z.coerce.number().default(3000),
  NODE_ENV: z.enum(["development", "production", "test"]).default("development"),
  DATABASE_URL: z.string().default("sqlite.db"),
});

const parsed = configSchema.safeParse(process.env);

if (!parsed.success) {
  console.error("❌ Invalid environment variables:", parsed.error.flatten().fieldErrors);
  process.exit(1);
}

export const config = parsed.data

// src/test/setup.ts
process.env.DATABASE_URL = ":memory:";

client -> server communication

•Prefer trpc with react query for fullstack projects (when the server and client are in the same package)
•Otherwise prefer graphql

TypeScript Config

json

{
  "compilerOptions": {
    "target": "ESNext",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true
  }
}

Package.json scripts

The following are my preferred set of package.json scripts. Not all scripts are relevant to all projects e.g. library packages will not have db scripts

jsonc

{
  "scripts": {
    "dev": "bun run --watch src/index.ts",
    
    "db:generate": "drizzle-kit generate",
    "db:migrate": "drizzle-kit migrate",
    "db:studio": "drizzle-kit studio",
    
    "typecheck": "tsc --noEmit",
    
    "format": "oxfmt src",
    "format:check": "oxfmt src --check",

    "lint": "oxlint --type-aware",
    "lint:fix": "oxlint --type-aware --fix --fix-suggestions --fix-dangerously",

    "fix": "bun format && bun lint:fix",

    "check": "concurrently 'bun:format' 'bun:lint:fix' 'bun:typecheck' 'bun:test' 'bun:test:e2e'",
    
    "test": "bun test",
    "test:e2e": "playwright test"
  }
}

Linting Setup

Use Oxlint and Oxfmt from OXC

json

// .oxlintrc.json
{
  "$schema": "./node_modules/oxlint/configuration_schema.json",
  "plugins": ["typescript"],
  "rules": {
    "typescript/no-floating-promises": "error",
    "typescript/no-unsafe-assignment": "warn"
  }
}

json

// .oxfmtrc.json
{
  "$schema": "./node_modules/oxfmt/configuration_schema.json",
  "trailingComma": "all",
  "printWidth": 80,
  "ignorePatterns": []
}

Fix linting errors & formatting errors with fix script, e.g. bun run fix or pnpm run fix.

Git Hooks

Use npm dependencies simple-git-hooks & lint-staged

json

{
  "simple-git-hooks": {
    "pre-commit": "pnpm i --frozen-lockfile --ignore-scripts --offline && pnpm lint-staged"
  },
  "lint-staged": { "*": "pnpm fix" },
  "scripts": { "prepare": "pnpm simple-git-hooks" }
}

Test Conventions

•Test files: foo.ts → foo.test.ts (same directory)
•Use describe/it API (not test)

References

Topic	Description	Reference
Deployment and CI/CD Setup	Buildkite pipelines, docker configuration	deployment