kebab-case-filenames

Enforce consistent file naming conventions across source directories.

Rule details

Inconsistent file naming (mixing camelCase, PascalCase, snake_case, and kebab-case) makes files harder to find and causes case-sensitivity issues across operating systems. This rule validates every scoped file name against a regex pattern and suggests corrections.

Examples of incorrect code

src/
  helpers/
    pathUtils.ts        ← camelCase
    Git_Helper.ts       ← PascalCase + snake_case
    ADRWriter.ts        ← PascalCase

Examples of correct code

src/
  helpers/
    path-utils.ts
    git-helper.ts
    adr-writer.ts

Rule implementation

/// <reference path="../rules.d.ts" />
import { basename } from "node:path";

const KEBAB_CASE = /^[a-z][a-z0-9]*(-[a-z0-9]+)*\.(ts|tsx|js|jsx)$/;

export default {
  rules: {
    "kebab-case-filenames": {
      description: "Source files must use kebab-case naming",
      async check(ctx) {
        for (const file of ctx.scopedFiles) {
          const name = basename(file);

          // Skip test files and type declaration files
          if (name.endsWith(".test.ts") || name.endsWith(".d.ts")) continue;

          if (!KEBAB_CASE.test(name)) {
            ctx.report.violation({
              message: `File "${name}" does not follow kebab-case naming convention`,
              file,
              fix: `Rename to ${name.replace(/([a-z])([A-Z])/g, "$1-$2").toLowerCase()}`,
            });
          }
        }
      },
    },
  },
} satisfies RuleSet;

When to use it

When your team has standardized on a naming convention and wants to enforce it automatically. Adapt the regex for your convention:

// PascalCase (React components)
const PASCAL_CASE = /^[A-Z][a-zA-Z0-9]*\.(ts|tsx)$/;

// camelCase
const CAMEL_CASE = /^[a-z][a-zA-Z0-9]*\.(ts|tsx|js|jsx)$/;

// snake_case (Python-style)
const SNAKE_CASE = /^[a-z][a-z0-9]*(_[a-z0-9]+)*\.(ts|tsx|js|jsx)$/;

When not to use it

When your project intentionally mixes naming conventions (e.g., PascalCase for React components and kebab-case for utilities), or when migrating a legacy codebase where bulk renames are not feasible.