@mslmio/eslint-config

Shareable ESLint flat config plus a small plugin of house rules — the kind of convention teams write down and then enforce with nothing.

pnpm add -D @mslmio/eslint-config eslint

Use it

// A backend service or a non-UI library - installs no Tailwind/React tooling.
import { lib, typeChecked } from "@mslmio/eslint-config";
export default [...lib, typeChecked(import.meta.dirname)];

// Anything rendering Tailwind. Needs @shadcn/lint (and eslint-plugin-react-hooks
// for uiLib) installed alongside - both are OPTIONAL peers.
import { uiLib } from "@mslmio/eslint-config/ui";
export default [...uiLib];

Two entry points on purpose. A backend service has no Tailwind and no React, so keeping the UI half behind /ui means the root entry resolves neither @shadcn/lint nor eslint-plugin-react-hooks, nor oxc-parser's native binaries.

| Preset | For | Adds | |---|---|---| | house | anything TS/JS | no-property-shorthand, curly: all, us-spelling, no-express-json-spaces, no-invisible-characters | | lib | a published library | house + no-lib-process-env, no-module-scope-init | | ui | anything rendering Tailwind | house + require-leading-with-text-size, prefer-copy-icon, prefer-table-facets, no-viewport-height | | uiLib | a published UI library | lib + ui |

Rules

| Rule | What it says | |---|---| | no-upward-import | A package may not import a tier above it, or a sibling leaf. Off until configured — see below | | no-property-shorthand | Always { key: key }; exempts destructuring and imports | | no-lib-process-env | A library never reads process.env — configuration is passed in | | no-module-scope-init | No client/config built at module scope; build lazily and memoize | | no-express-json-spaces | Express's json spaces indents but drops the trailing newline | | prefer-copy-icon | lucide Copy, not Clipboard | | us-spelling | US spelling in comments, string and template literals, and JSX text; identifiers are not checked | | require-leading-with-text-size | An arbitrary Tailwind text size must state its own line height | | prefer-table-facets | A kind: "select" filter lists the values its rows hold (facets), never a literal options list | | no-invisible-characters | No bidi control character anywhere, strings and comments included (Trojan Source), and no zero-width space, joiner or direction mark outside text: write one as an escape | | no-viewport-height | A height is never vh, lvh or *-screen, the viewport with the browser's toolbars hidden, which a bottom toolbar then covers: svh floors a page, dvh sizes a full-height surface or caps a box |

us-spelling fixes comments and JSX text, and only reports strings and templates, since one can be a wire value. It skips regex literals — a pattern matching scraped text has to accept both spellings — and takes allow for proper names that keep their own: ["mslmio/us-spelling", "error", { allow: ["Macquarie Data Centres"] }]. Only the phrase itself, matched case included, is exempt: a British word beside it in the same comment or string still reports.

no-lib-process-env exempts main.* by default: a runnable entry point living in a library directory IS the service. Override with { entryPoints: [...] }.

Every rule that explains itself takes an optional docsUrl, appended to the message so you can point at your own write-up: ["mslmio/no-lib-process-env", "error", { docsUrl: "https://..." }].

no-upward-import

A workspace layered into ordered tiers plus any number of leaves. A tier may import the tiers below it; a leaf may import every tier but no other leaf. Nothing reaches up.

["mslmio/no-upward-import", "error", {
    tiers: ["base", "platform"],   // ordered, lowest first
    exempt: ["tools"],             // outside the layering entirely
    typeDirs: ["svc", "lib", "web"],
    docsUrl: "https://example.com/layering",
}]

It is a no-op until tiers is set, which is the default. The leaves are discovered from the workspace root — the directory holding every tier as a child — rather than listed: any other child containing one of typeDirs is a leaf. So adding a leaf needs no config change, and no package has to hold a list of its siblings.

A file's namespace is its top-level directory under that root, so neither the path the workspace is checked out at nor the package's own name changes the verdict. Outside a workspace there is no root, and a scoped package's scope is its namespace.

License

MIT