unique_by

No two files matching select may share the value of key (a path template; tokens {path}/{dir}/{basename}/{stem}/{ext}/{parent_name}). Catches basename collisions across subdirectories. With case_insensitive: true the key is folded to lowercase before grouping, so README.md and readme.md collide — the case-insensitive-filesystem hazard (Windows / macOS).

Options

Option	Type	Required	Default	Description
case_insensitive	boolean		false	Fold the key to lowercase before grouping, so keys that collide only under case-folding count as duplicates - the case-insensitive-filesystem hazard (Windows / macOS).
key	string		{basename}	Path-template producing a key per matched file. Default: {basename}.
select	string	yes		Glob selecting the files to deduplicate.

Plus the common level, id, and when fields. This rule analyses the whole repository, so it takes no paths or expect_matches. This table is generated from the JSON Schema; option types and defaults are authoritative.

Example

Two files colliding on the same stem

The rule fires on this repository:

• a/
• a/util.rs⚠

  ⚠ warning unique-rs-stems

  duplicate key "util" shared by 2 file(s): a/util.rs, b/util.rs related: shares this key: b/util.rs

• b/
• b/util.rs✓
• c/
• c/other.rs✓

a/util.rs

pub fn a() {}

b/util.rs

pub fn b() {}

c/other.rs

pub fn c() {}

With this .alint.yml:

version: 1
rules:
  - id: unique-rs-stems
    kind: unique_by
    select: "**/*.rs"
    key: "{stem}"
    level: warning

alint check reports:

--- a/util.rs ------------------------------------------------------------------
  !  warning  unique-rs-stems
              duplicate key "util" shared by 2 file(s): a/util.rs, b/util.rs
              related: shares this key: b/util.rs

Summary (1 violation):
  ! 1 warning
  0 passing * 1 failing

Every file has a distinct stem

This repository is compliant:

• src/
• src/alpha.rs✓
• src/beta.rs✓
• src/gamma.rs✓

With this .alint.yml:

version: 1
rules:
  - id: unique-rs-stems
    kind: unique_by
    select: "**/*.rs"
    key: "{stem}"
    level: warning

alint check reports:

v All 1 rule(s) passed.