@paciolan/code-standards

Paciolan's shared code standards in one package, consumed through three subpath exports:

| Subpath | What it is | | --- | --- | | @paciolan/code-standards/eslint/* | ESLint flat configs (ESLint 9 and 10) plus the pac custom-rules plugin | | @paciolan/code-standards/prettier | Org-wide Prettier settings | | @paciolan/code-standards/tsconfig/* | TypeScript config presets (roles × layers) |

One dependency, one version bump per repo.

npm install --save-dev @paciolan/code-standards eslint prettier typescript

Peer requirements: eslint ^9 or ^10, prettier ^3, typescript >=5 (only if you use the TypeScript-aware configs or tsconfig presets).

ESLint

Pick the entry matching the repo, re-export it from eslint.config.mjs, and delete the repo's hand-rolled rules. Entries are cumulative — each one includes everything below it in the table:

| Entry | Adds | Use for | | --- | --- | --- | | eslint/base | eslint recommended, Prettier-as-error | plain JS utilities | | eslint/typescript | typescript-eslint recommended, unused-import auto-removal, _-prefix conventions | headless TS libraries | | eslint/react | browser globals, react-hooks, import sorting | React components/libs | | eslint/react-query | @tanstack/query correctness rules | operator remote components | | eslint/node | node globals, security + n plugins, type-aware promise rules, no-console | node services (layered on typescript) | | eslint/nest | Nest-specific guards | NestJS services | | eslint/lambda | pac/no-direct-aws-sdk-v3-instance | AWS lambdas |

// eslint.config.mjs — operator remote component
import reactQuery from "@paciolan/code-standards/eslint/react-query";

export default reactQuery;

// eslint.config.mjs — node service / nest / lambda, adding repo-local tweaks
import node from "@paciolan/code-standards/eslint/node";

export default [
  ...node,
  { rules: { "@typescript-eslint/no-explicit-any": "off" } }
];

Notes:

• Type-aware rules (no-floating-promises, no-misused-promises, return-await in the node family) resolve your tsconfig.json via typescript-eslint's project service. Run ESLint from the repo root; if you don't, add { languageOptions: { parserOptions: { tsconfigRootDir: import.meta.dirname } } }.
• react-hooks is pinned to the classic pair (rules-of-hooks error, exhaustive-deps warn). The plugin's v6+ recommended preset bundles the React Compiler rule set; adopting those is a deliberate future change to this package.
• Unused code: unused imports are removed by --fix; unused vars/args/catch params warn unless named with a leading _.
• Repos that register additional plugins (e.g. eslint-plugin-react) do so in their own config entry appended after the shared array.

Custom rules (pac/ plugin)

Standalone usage:

import pacPlugin from "@paciolan/code-standards/eslint/plugin";

export default [
  {
    plugins: { pac: pacPlugin },
    rules: { "pac/no-direct-aws-sdk-v3-instance": "error" }
  }
];

pac/no-direct-aws-sdk-v3-instance

Disallows binding *Client names from @aws-sdk/client-* packages (both import and require destructuring), so lambdas and services reuse the shared singleton clients instead of constructing their own per call site. Enabled by the lambda entry; test files are exempt. Disable it inline in the one module that owns the singletons:

// eslint-disable-next-line pac/no-direct-aws-sdk-v3-instance
import { S3Client } from "@aws-sdk/client-s3";

Prettier

Point the prettier key of package.json at the shared config and delete .prettierrc:

{
  "prettier": "@paciolan/code-standards/prettier"
}

Settings: tabWidth: 2, trailingComma: "none" (matches the operator fleet and existing code; everything else is Prettier defaults). The ESLint configs enforce the same settings through prettier/prettier, so editors and CI can't drift.

TypeScript

Extend one role, then stack layers as needed (later entries win):

| Role | For | | --- | --- | | tsconfig/react-lib | browser React components/libs (typecheck-only; the bundler emits) | | tsconfig/node-service | node services compiled with tsc (NodeNext, no DOM lib) | | tsconfig/nest | NestJS services (CommonJS + legacy decorators) | | tsconfig/lambda | AWS lambdas (node-service alias, stable extension point) |

| Layer | Effect | | --- | --- | | tsconfig/strict | extra strictness: noUncheckedIndexedAccess, noImplicitReturns, noImplicitOverride | | tsconfig/jest | types: ["node", "jest"] | | tsconfig/vitest | types: ["node", "vitest/globals"] | | tsconfig/esmodule | NodeNext module semantics (flip a nest/service to ESM) | | tsconfig/commonjs | CommonJS module semantics |

// tsconfig.json — React component with vitest
{
  "extends": [
    "@paciolan/code-standards/tsconfig/react-lib",
    "@paciolan/code-standards/tsconfig/vitest"
  ],
  "include": ["src"]
}

// tsconfig.json — ESM NestJS service
{
  "extends": [
    "@paciolan/code-standards/tsconfig/nest",
    "@paciolan/code-standards/tsconfig/esmodule"
  ],
  "compilerOptions": { "baseUrl": "src/", "outDir": "dist/" },
  "include": ["./"]
}

Every role is strict: true. Heads-up: types replaces rather than merges across extends — a repo needing extra ambient types (e.g. @testing-library/jest-dom) sets the full types array itself.

Versioning and publishing

Releases are cut by semantic-release from conventional commits on master (fix: → patch, feat: → minor). A rule/config change that will produce new errors in consuming repos is a breaking change — release it as a major.

Attribution

The tsconfig preset structure (roles extended by layers) is adapted from the MIT-licensed @code-style/typescript-configs by Louis Orleans.