@distrohelena/linter

TypeScript-only Helena lint rules for modern ESLint flat config.

Repository: https://github.com/distrohelena/helena-linter

Install

npm install -D @distrohelena/linter eslint typescript @typescript-eslint/parser

Usage

import helenaLinter from "@distrohelena/linter";

export default [...helenaLinter.configs.recommended];

This enables the canonical Helena rule IDs:

• @distrohelena/linter/control-body-braces
• @distrohelena/linter/control-block-following-spacing
• @distrohelena/linter/declaration-leading-spacing
• @distrohelena/linter/declaration-spacing
• @distrohelena/linter/early-return
• @distrohelena/linter/exit-spacing
• @distrohelena/linter/if-else-if-chain
• @distrohelena/linter/if-leading-spacing
• @distrohelena/linter/if-following-spacing
• @distrohelena/linter/multiline-block-layout
• @distrohelena/linter/redundant-else-if

Per-Rule Imports

import controlBodyBracesRule from "@distrohelena/linter/control-body-braces";
import controlBlockFollowingSpacingRule from "@distrohelena/linter/control-block-following-spacing";
import declarationLeadingSpacingRule from "@distrohelena/linter/declaration-leading-spacing";
import declarationSpacingRule from "@distrohelena/linter/declaration-spacing";
import earlyReturnRule from "@distrohelena/linter/early-return";
import exitSpacingRule from "@distrohelena/linter/exit-spacing";
import ifElseIfChainRule from "@distrohelena/linter/if-else-if-chain";
import ifLeadingSpacingRule from "@distrohelena/linter/if-leading-spacing";
import ifFollowingSpacingRule from "@distrohelena/linter/if-following-spacing";
import multilineBlockLayoutRule from "@distrohelena/linter/multiline-block-layout";
import redundantElseIfRule from "@distrohelena/linter/redundant-else-if";

Included Rules

Examples below show the shape each rule expects, not every supported edge case.

@distrohelena/linter/control-body-braces

Requires braces for if, else, for, for...in, for...of, while, and do...while bodies.

Bad:

if (ready)
    run();

Good:

if (ready) {
    run();
}

@distrohelena/linter/control-block-following-spacing

Requires a blank line after a completed for, while, do, switch, or try statement before the next sibling statement.

Bad:

for (const item of items) {
    process(item);
}
finish();

Good:

for (const item of items) {
    process(item);
}

finish();

@distrohelena/linter/declaration-leading-spacing

Requires a blank line before a declaration statement when the previous sibling statement is not a declaration.

Bad:

logStart();
const result = compute();

Good:

logStart();

const result = compute();

@distrohelena/linter/declaration-spacing

Requires a blank line after a declaration statement before the next non-declaration sibling statement.

Bad:

const result = compute();
render(result);

Good:

const result = compute();

const total = computeTotal(result);

render(result);

@distrohelena/linter/early-return

Flags wrapped happy-path if blocks that should be rewritten as guard clauses.

Bad:

if (isValid(user)) {
    save(user);
    return true;
}

return false;

Good:

if (!isValid(user)) {
    return false;
}

save(user);
return true;

@distrohelena/linter/exit-spacing

Requires a blank line before return, throw, break, and continue statements.

Bad:

updateState();
return value;

Good:

updateState();

return value;

@distrohelena/linter/if-else-if-chain

Flags sibling if branches that should be written as else if.

Bad:

if (primary) {
    return "a";
}

if (secondary) {
    return "b";
}

Good:

if (primary) {
    return "a";
} else if (secondary) {
    return "b";
}

@distrohelena/linter/if-leading-spacing

Requires a blank line before an if statement when it has a previous sibling statement.

Bad:

prepare();
if (ready) {
    run();
}

Good:

prepare();

if (ready) {
    run();
}

@distrohelena/linter/if-following-spacing

Requires a blank line after a completed if or if / else if / else chain before the next sibling statement.

Bad:

if (ready) {
    run();
}
cleanup();

Good:

if (ready) {
    run();
}

cleanup();

@distrohelena/linter/multiline-block-layout

Requires non-empty code blocks to break across lines. Empty blocks may remain on one line, and object, collection, and anonymous initializer braces are excluded.

Bad:

if (ready) { run(); }

Good:

if (ready) {
    run();
}

@distrohelena/linter/redundant-else-if

Flags else if branches that are just the exact complement of the previous if, which should be plain else.

Bad:

if (value === null) {
    handleMissing();
} else if (value !== null) {
    handleValue(value);
}

Good:

if (value === null) {
    handleMissing();
} else {
    handleValue(value);
}

Scope

• TypeScript only
• ESLint flat config only
• No legacy .eslintrc support

Local Verification

npm test -- --runInBand
npm run build
npm run lint
npm run lint:smoke