monorepo/cargo-workspace@v1

Workspace-aware overlay for Cargo workspaces. Layered on top of monorepo@v1 (which covers polyglot package-dir conventions) and rust@v1 (which covers Rust source hygiene). Adopt with:

extends:
  - alint://bundled/monorepo@v1
  - alint://bundled/rust@v1
  - alint://bundled/monorepo/cargo-workspace@v1

Gated by facts.is_cargo_workspace — the root Cargo.toml must declare a [workspace] table. Outside an actual workspace (e.g. a single-crate repo, or a polyglot tree whose Rust portion isn't a workspace), the rules silently no-op so the ruleset is safe to extend unconditionally.

v0.9.18 SCOPE NOTE — non-canonical workspace layouts:

The per-member rules below use select: "crates/*" — the canonical Cargo workspace convention used by rust-lang/rust, alint itself, and most published workspaces. Workspaces with non-canonical layouts (deno's ext/* + libs/* + runtime/ + cli/; clap's clap_builder, clap_derive, etc.) will see the bundled per-member checks silently no-op against their tree.

Non-canonical adopters should redefine the per-member rules in their .alint.yml with the correct select: glob (rule IDs reused at the user level OVERRIDE the bundled definition while keeping the rule active). For example, deno's config carries:

- id: cargo-workspace-member-has-readme
  kind: for_each_dir
  select: "{ext/*,libs/*,runtime,cli}"
  when_iter: 'iter.has_file("Cargo.toml")'
  require: [{ kind: file_exists, paths: "{path}/README.md" }]

(for_each_dir.select: accepts a single glob; brace expansion handles multi-pattern intent.)

The principled fix — a select_from: "$.workspace.members" refinement that derives the iteration set from the root Cargo.toml's [workspace] members array — ships in v0.10 alongside the toml_path_array_iter rule-kind design. Tracking: v0.10 design candidate "*_path_array_iter".

What it checks

3 rules. Each links to its section below, which explains the check and shows its definition.

Rule	Reports
cargo-workspace-members-declared `error`	Cargo workspace must declare `members = [...]` under `[workspace]`.
cargo-workspace-member-has-readme `warning`	Cargo workspace members should have a README.md so the crate's purpose is discoverable from the directory tree.
cargo-workspace-member-declares-name `warning`	Workspace member's Cargo.toml must declare `[package]` with a `name` field.

All 3 rules run only when facts.is_cargo_workspace holds, so the ruleset stays quiet in repositories it doesn't apply to.

Rules

`cargo-workspace-members-declared`

The workspace root must declare its members. A [workspace] table without members = [...] is broken — Cargo rejects it. Catching this here keeps the failure local to alint output.

kind: toml_path_matches
level: error
when: facts.is_cargo_workspace
policy: https://doc.rust-lang.org/cargo/reference/workspaces.html

Cargo workspace must declare members = [...] under [workspace]. Without it, cargo build fails to resolve the package graph.

- id: cargo-workspace-members-declared
  when: facts.is_cargo_workspace
  kind: toml_path_matches
  paths: Cargo.toml
  path: "$.workspace.members[*]"
  matches: ".+"
  level: error
  message: >-
    Cargo workspace must declare `members = [...]` under
    `[workspace]`. Without it, `cargo build` fails to resolve
    the package graph.
  policy_url: "https://doc.rust-lang.org/cargo/reference/workspaces.html"

`cargo-workspace-member-has-readme`

Every actual workspace member (a crates/* directory that has a Cargo.toml of its own) needs a README. Pre-v0.5.2, this would have fired on crates/notes/ even if it wasn't a real package — when_iter: scopes the iteration to just the package dirs.

kind: for_each_dir
level: warning
when: facts.is_cargo_workspace

Cargo workspace members should have a README.md so the crate's purpose is discoverable from the directory tree.

- id: cargo-workspace-member-has-readme
  when: facts.is_cargo_workspace
  kind: for_each_dir
  select: "crates/*"
  when_iter: 'iter.has_file("Cargo.toml")'
  require:
    - kind: file_exists
      paths: "{path}/README.md"
  level: warning
  message: >-
    Cargo workspace members should have a README.md so the
    crate's purpose is discoverable from the directory tree.

`cargo-workspace-member-declares-name`

Each member's Cargo.toml should declare its package name and edition — the two fields most commonly missing from hand-rolled members.

kind: for_each_dir
level: warning
when: facts.is_cargo_workspace

Workspace member's Cargo.toml must declare [package] with a name field.

- id: cargo-workspace-member-declares-name
  when: facts.is_cargo_workspace
  kind: for_each_dir
  select: "crates/*"
  when_iter: 'iter.has_file("Cargo.toml")'
  require:
    - kind: toml_path_matches
      paths: "{path}/Cargo.toml"
      path: "$.package.name"
      matches: '^[A-Za-z][A-Za-z0-9_-]*$'
  level: warning
  message: >-
    Workspace member's Cargo.toml must declare
    `[package]` with a `name` field.

Facts

The when: clauses above read these facts. Each is resolved once per run; alint facts prints what they resolved to in your repository.

facts:
  - id: is_cargo_workspace
    file_content_matches:
      paths: Cargo.toml
      pattern: '(?m)^\[workspace\]'

Customize

Every rule here can be overridden by id from your own .alint.yml: change its level, or set level: off to drop it. An id that doesn't exist is an error at config load, so a typo can't silently pass.

extends:
  - alint://bundled/monorepo/cargo-workspace@v1
rules:
  - id: cargo-workspace-members-declared
    level: off
  - id: cargo-workspace-member-has-readme
    level: error

To take only part of the ruleset, filter it where you extend it with only: or except::

extends:
  - url: alint://bundled/monorepo/cargo-workspace@v1
    except: [cargo-workspace-members-declared]

Bundled rulesets covers versioning and how rulesets combine.

Source

The full ruleset definition, comments included, is committed at crates/alint-dsl/rulesets/v1/monorepo/cargo-workspace.yml in the alint repo.