editorconfig_conforms

Enforce selected formatting properties from the repository's own .editorconfig files without repeating those values in .alint.yml.

The rule discovers only .editorconfig files between each selected file and the lint root; a developer's parent-directory policy can never affect the result. It follows EditorConfig section order, nested-file precedence, root = true, unset, slash-relative globs, */**/?, literal character classes (including the specification's non-separator treatment of / inside a complete class), brace alternatives, and ascending numeric ranges. Policy files follow the EditorConfig grammar: UTF-8 with LF or CRLF separators, = property delimiters, and ignored non-root preamble pairs. Every finding points back to the declaration that supplied its effective policy. An unreadable or malformed policy file and an invalid value for a supported property are resource_read or resource_parse analysis failures rather than silent passes.

Supported properties are indent_style (plus numeric indent_size / tab_width), end_of_line (lf, crlf, or cr), charset (latin1, utf-8, utf-8-bom, utf-16be, or utf-16le), trim_trailing_whitespace, insert_final_newline, and positive-integer max_line_length (off disables it). Space indentation enforces numeric indent_size; tab indentation uses as many tabs as the effective tab width permits and allows only the remaining sub-tab-width spaces. Target-file text checks recognize LF, CRLF, and CR as physical line endings. A false trim_trailing_whitespace imposes no prohibition; insert_final_newline: false requires a non-empty file not to end in a line break. Unknown section properties remain available to other EditorConfig plugins and are ignored. Check-only: a policy-derived multi-operation repair needs the later transactional edit-plan surface.

Options

This rule takes no kind-specific options.

Plus the common paths, level, id, when, scope_filter, and expect_matches fields. This table is generated from the JSON Schema; option types and defaults are authoritative.

Example

Files that violate their EditorConfig policy are reported

The rule fires on this repository:

• .editorconfig✓
• bad.txt✗

  ✗ error editor-policy

  1:1 line 1 does not use EditorConfig space indentation related: EditorConfig `indent_style` policy: .editorconfig:4:1-4:21

  ✗ error editor-policy

  1:14 line 1 has trailing whitespace related: EditorConfig `trim_trailing_whitespace` policy: .editorconfig:6:1-6:32

  ✗ error editor-policy

  1:17 file does not end with a newline related: EditorConfig `insert_final_newline` policy: .editorconfig:7:1-7:28

.editorconfig

root = true

[*.txt]
indent_style = space
indent_size = 2
trim_trailing_whitespace = true
insert_final_newline = true

bad.txt

  bad trailing

With this .alint.yml:

version: 1
rules:
  - id: editor-policy
    kind: editorconfig_conforms
    paths: "**/*.txt"
    level: error

alint check reports:

--- bad.txt --------------------------------------------------------------------
  x  error    editor-policy
              1:1  line 1 does not use EditorConfig space indentation
              related: EditorConfig `indent_style` policy: .editorconfig:4:1-4:21
  x  error    editor-policy
              1:14  line 1 has trailing whitespace
              related: EditorConfig `trim_trailing_whitespace` policy: .editorconfig:6:1-6:32
  x  error    editor-policy
              1:17  file does not end with a newline
              related: EditorConfig `insert_final_newline` policy: .editorconfig:7:1-7:28

Summary (3 violations):
  x 3 errors
  0 passing * 1 failing

Nested EditorConfig sections merge and unset inherited policy

This repository is compliant:

• .editorconfig✓
• docs/
• docs/.editorconfig✓
• docs/guide.txt✓

.editorconfig

root = true

[*.txt]
indent_style = space
indent_size = 2
trim_trailing_whitespace = true
insert_final_newline = true

docs/.editorconfig

[*.txt]
trim_trailing_whitespace = unset

docs/guide.txt

  aligned trailing spaces

With this .alint.yml:

version: 1
rules:
  - id: editor-policy
    kind: editorconfig_conforms
    paths: "**/*.txt"
    level: error

alint check reports:

v All 1 rule(s) passed.