Steiger

Universal file structure and project architecture linter.

It's pronounced "STY-kh-er" — like tiger with an S up front and the "ch" of loch for the G. ("Steiger" is Dutch for "scaffold".)

Note

The project is in beta and in active development. Some APIs may change.

Note

Version 0.5.0 introduced a new config file format. We have a codemod to automatically update your config, see the migration guide.

Features

• Built-in set of rules to validate adherence to Feature-Sliced Design
• Watch mode
• Rule configurability
• Language server
• Extensions for VS Code, other VS Code-based editors and JetBrains IDEs

Installation

npm i -D steiger

# If you want to check compliance to Feature-Sliced Design, also install this:
npm i -D @feature-sliced/steiger-plugin

Usage

npx steiger ./src

To run in watch mode, add -w/--watch to the command:

npx steiger ./src --watch

To report errors only and hide warnings, use --ignore-warnings. --ignore-warnings cannot be used together with --fail-on-warnings.

npx steiger ./src --ignore-warnings

Configuration

Steiger is zero-config! If you don't want to disable certain rules, you can safely skip this section.

Steiger is configurable via cosmiconfig. That means that you can create a steiger.config.ts or steiger.config.js file in the root of your project to configure the rules. Import { defineConfig } from "steiger" to get autocompletion.

The config file shape is highly inspired by ESLint's config file, so if you have configured ESLint before, you'll find it easy to configure Steiger.

Example

// ./steiger.config.js
import { defineConfig } from 'steiger'
import fsd from '@feature-sliced/steiger-plugin'

export default defineConfig([
  ...fsd.configs.recommended,
  {
    // disable the `public-api` rule for files in the Shared layer
    files: ['./src/shared/**'],
    rules: {
      'fsd/public-api': 'off',
    },
  },
])

Tip

If you want Steiger to ignore certain files, add an object like this to the config array:

defineConfig([, /* … */ { ignores: ['**/__mocks__/**'] }])

Comprehensive showcase of the config file syntax

  // ./steiger.config.ts
  import { defineConfig } from 'steiger'
  import fsd from '@feature-sliced/steiger-plugin'
  
  export default defineConfig([
    ...fsd.configs.recommended,
    {
      // ignore all mock files for all rules
      ignores: ['**/__mocks__/**'],
    },
    {
      files: ['./src/shared/**'],
      rules: {
        // disable public-api rule for files in /shared folder
        'fsd/public-api': 'off',
      },
    },
    {
      files: ['./src/widgets/**'],
      ignores: ['**/discount-offers/**'],
      rules: {
        // disable no-segmentless-slices rule for all widgets except /discount-offers
        'fsd/no-segmentless-slices': 'off',
      },
    },
  ])

You can see more examples here

Migration from 0.4.0

Version 0.5.0 introduced a new config file format. Follow the instructions to migrate your config file.

Rules

Currently, Steiger is not extendable with more rules, though that will change in the near future. The built-in rules check for the project's adherence to Feature-Sliced Design.

Rule	Description
fsd/ambiguous-slice-names	Forbid slice names that that match some segment’s name in the Shared layer.
fsd/excessive-slicing	Forbid having too many ungrouped slices or too many slices in a group.
fsd/forbidden-imports	Forbid imports from higher layers and cross-imports between slices on the same layer.
fsd/no-cross-imports	[disabled] Forbid cross-imports between slices on the same layer.
fsd/no-higher-level-imports	[disabled] Forbid imports from higher layers.
fsd/inconsistent-naming	Ensure that all entities are named consistently in terms of pluralization.
fsd/insignificant-slice	Detect slices that have just one reference or no references to them at all.
fsd/no-layer-public-api	Forbid index files on the layer level.
fsd/no-public-api-sidestep	Forbid going around the public API of a slice to import directly from an internal module in a slice.
fsd/no-reserved-folder-names	Forbid subfolders in segments that have the same name as other conventional segments.
fsd/no-segmentless-slices	Forbid slices that don't have any segments.
fsd/no-segments-on-sliced-layers	Forbid segments (like ui, lib, api ...) that appear directly in sliced layer folders (entities, features, ...)
fsd/no-ui-in-app	Forbid having the ui segment on the App layer.
fsd/public-api	Require slices (and segments on sliceless layers like Shared) to have a public API definition.
fsd/repetitive-naming	Ensure that all entities are named consistently in terms of pluralization.
fsd/segments-by-purpose	Discourage the use of segment names that group code by its essence, and instead encourage grouping by purpose
fsd/shared-lib-grouping	Forbid having too many ungrouped modules in shared/lib.
fsd/typo-in-layer-name	Ensure that all layers are named without any typos.
fsd/no-processes	Discourage the use of the deprecated Processes layer.
fsd/import-locality	[disabled] Require that imports from the same slice be relative and imports from one slice to another be absolute.
fsd/no-wildcard-exports	[disabled] Forbid wildcard re-exports (export * from) in public APIs.

Contribution

Feel free to report an issue or open a discussion. Ensure you read our Code of Conduct first though :)

To get started with the codebase, see our Contributing guide.

Legal info

Project licensed under MIT License. Here's what it means