id: mod-declaration-visibility-order
language: rust
severity: error
message: "`$VIS mod $M;` is declared directly after a module with narrower visibility"
note: Declare modules widest visibility first, `pub`, then `pub(crate)` and `pub(super)`, then private, with a blank line between groups so that rustfmt keeps them apart.
utils:
  # `#[macro_use]` has to stay textually first, so such a declaration never counts
  # as a predecessor.
  after-macro-use:
    follows:
      kind: attribute_item
      regex: macro_use
      stopBy: neighbor
  restricted-predecessor:
    all:
      - pattern: pub mod $N;
      - has:
          kind: visibility_modifier
          regex: '^pub\('
          stopBy: neighbor
      - not:
          matches: after-macro-use
  private-predecessor:
    all:
      - pattern: mod $N;
      - not:
          matches: after-macro-use
  # Comments and attributes sit between declarations without separating them.
  between-declarations:
    any:
      - kind: line_comment
      - kind: block_comment
      - kind: attribute_item
rule:
  any:
    - all:
        - pattern: pub mod $M;
        - has:
            kind: visibility_modifier
            pattern: $VIS
            regex: "^pub$"
            stopBy: neighbor
        - follows:
            any:
              - matches: restricted-predecessor
              - matches: private-predecessor
            stopBy:
              not:
                matches: between-declarations
    - all:
        - pattern: pub mod $M;
        - has:
            kind: visibility_modifier
            pattern: $VIS
            regex: '^pub\('
            stopBy: neighbor
        - follows:
            matches: private-predecessor
            stopBy:
              not:
                matches: between-declarations