Steiger for Rust

A native, Node.js-free rewrite of feature-sliced/steiger: a project-architecture linter for Feature-Sliced Design.

The current implementation follows Steiger 0.6.0 and @feature-sliced/steiger-plugin 0.7.0. It contains the same 20 FSD rules, enables the same 17-rule recommended preset, keeps the familiar CLI flags, and uses Oxc to analyze JavaScript and TypeScript imports.

Quick start

npm install --save-dev steiger-rust
npx steiger ./src

The npm meta-package downloads only the native package for the current operating system and architecture. That platform package exposes steiger as the Rust executable itself: invoking the CLI does not start Node.js or a JavaScript launcher. npm is only used to install the package.

To build from source instead:

cargo install --path . --locked
steiger ./src

When no path is provided, Steiger selects ./src, then ./app, then the current folder.

steiger ./src --watch
steiger ./src --fix
steiger ./src --reporter json
steiger ./src --fail-on-warnings
steiger ./src --baseline ./fsd-errors.json
steiger --list-rules

The exit code is 1 when errors remain, or when warnings remain together with --fail-on-warnings. Invalid input or configuration returns 2.

Supported platforms

GitHub Releases and npm provide native binaries for:

| Operating system | Architectures | Runtime variant | | --- | --- | --- | | macOS | x64, arm64 | Darwin | | Linux | x64, arm64 | glibc and musl | | Windows | x64, arm64 | MSVC |

Other Rust targets can still be built from source when the dependencies support them.

Validate against existing FSD debt

For gradual migrations, --baseline accepts the checked-in fsd-errors.json format used by Terminal: a JSON object whose keys are rule names and whose values are arrays of paths. Paths are resolved relative to the baseline file.

steiger ./src --baseline ./fsd-errors.json
# --fsd-errors is an alias for --baseline

Known (rule, path) diagnostics are hidden. The command exits with 0 when no new diagnostics appear and 1 when the current result contains a pair absent from the baseline, making it suitable for pre-push hooks and CI. A reduction in existing diagnostics succeeds without rewriting the committed file.

Configuration

The native binary works without a configuration file. It searches the current folder and its parents for steiger.toml, .steiger.toml, steiger.config.toml, steiger.json, .steiger.json, or steiger.config.json.

Example steiger.toml:

global_ignores = ["**/__mocks__/**"]

[rules]
"fsd/no-processes" = "warn"

[[overrides]]
files = ["./src/shared/**"]

[overrides.rules]
"fsd/public-api" = "off"

[[overrides]]
files = ["./src/widgets/**"]
ignores = ["**/discount-offers/**"]

[overrides.rules]
"fsd/no-segmentless-slices" = "off"

JSON also accepts a Steiger-style flat array. Rules are built into the binary, so plugin objects are omitted:

[
  { "ignores": ["**/__mocks__/**"] },
  {
    "files": ["./src/shared/**"],
    "rules": { "fsd/public-api": "off" }
  }
]

Later matching overrides take precedence. A folder diagnostic receives the highest effective severity of the files below that folder, matching upstream Steiger's file-glob behavior.

JavaScript and TypeScript configuration files are intentionally not evaluated: doing that would make the native binary depend on Node.js. Use TOML or JSON, or pass a file explicitly with --config.

Language and module support

• JavaScript, JSX, TypeScript, TSX, MJS, CJS, MTS, and CTS through Oxc
• import, import(), and require() dependencies
• Vue and Svelte <script> blocks
• Astro frontmatter
• relative imports, directory indexes, TypeScript baseUrl/paths, extends, and project references through oxc_resolver
• .gitignore, .ignore, .git, node_modules, and Rust target exclusions

Rules

Run steiger --list-rules for the machine-readable list. The recommended preset includes:

• fsd/ambiguous-slice-names
• fsd/excessive-slicing
• fsd/forbidden-imports
• fsd/inconsistent-naming
• fsd/insignificant-slice
• fsd/no-layer-public-api
• fsd/no-public-api-sidestep
• fsd/no-reserved-folder-names
• fsd/no-segmentless-slices
• fsd/no-segments-on-sliced-layers
• fsd/no-ui-in-app
• fsd/public-api
• fsd/repetitive-naming
• fsd/segments-by-purpose
• fsd/shared-lib-grouping
• fsd/typo-in-layer-name
• fsd/no-processes

The upstream-compatible split rules fsd/no-cross-imports, fsd/no-higher-level-imports, and fsd/import-locality are available but disabled by default.

Development

cargo fmt --all -- --check
cargo clippy --all-targets --all-features -- -D warnings
cargo test --all-targets
cargo build --release

The npm packaging has a separate integration test. It installs local tarballs and verifies that .bin/steiger resolves directly to a native executable:

cargo build --release
node --test tests/npm_native_cli.mjs
node scripts/prepare-npm-release.mjs --check v0.1.0

See CONTRIBUTING.md for pull request guidance and RELEASING.md for the tag-based GitHub/npm release process.

License and upstream relationship

This project is an independent Rust implementation derived from the behavior and tests of the MIT-licensed upstream Steiger project.

Released under the MIT License.