Splints (Simple Pattern Lints)

Language-Agnostic LSP implementation providing IDE linting with customisable formatting/messages based on user-defined regex patterns

Installation

pip install splints

Neovim

Add the following to your config

vim.lsp.config["splints"] = {
    cmd = { "splints" },
    filetypes = { "python" },
}
vim.lsp.enable("splints")

PyPI Package

Defining Rules

Add lint rules to a file named splints.yaml at the root of your repo. The location can be overridden by setting the environment variable SPLINTS_RULES

Required properties

• pattern (string): The regex expression used to find text matching this lint rule
• message (string): A description of the lint rule

Optional properties

• code (string): An optional identifier for the lint rule
• include_globs (list of strings): The lint rule will be active in files matching these globs. Defaults to ["*"]
• exclude_globs: (list of strings): The lint rule will be deactivated in files matching these globs - overrides include_globs. Defaults to []
• severity ("error", "warning", "info", "hint"): Changes how your LSP client formats the popup window
• tags ("deprecated", "unnecessary"): Changes how your LSP client formats the popup message text
• replacement_options (list of PatternReplacement objects - see below): The replacement options provided when your IDE requests a code action.

PatternReplacement properties

• description (string): Describe what the replacement will do. If no description is provided the description will be set to the replacement outcome.
• pattern (string): Matches text to replace from the characters matched by its parent lint rule pattern. Defaults to "(\n|.)*" (replaces all characters)
• replacement (string): A string or regex expression that describes the text replacement.
• imports (list of strings): A list of lines to add to the top of the file to import dependencies of the replacement.

Example Rule Definitions

Warn against type ignores

- pattern: '# type: ignore'
  message: 'Type ignores are only allowed in exceptional circumstances'

Disallow use of Any in Python files

- pattern: ': Any'
  message: 'Any should rarely be used as a type decorator. Use a more descriptive type'
  include_globs: ['*.py']

Disallow external use of private properties/methods

- pattern: '(?<!self)\._[^_]\w+'
  message: 'Do not reference private properties/methods directly'
  include_globs: ['*.py']
  severity: error

Prefer Javascript Spread Syntax

- pattern: '\w+\.concat\([\s\r\n]*\w+[\s\r\n]*\)'
  message: "concat should not be used. prefer spread notation ([...oldArr, ...newValues])"
  include_globs: ["*.js", "*.ts", "*.jsx", "*.tsx"]
  replacement_options:
  - description: Convert to spread notation
    pattern: "(\\w+|\\[.*])\\.concat\\([\\s\\r\\n]*(\\w+|\\[.*])[\\s\\r\\n]*\\)"
    replacement: "[...\\1, ...\\2]"

Text Replacement

Ensure zip() uses strict=True

- pattern: 'zip\((?!.*strict\s*=\s*True)[^)]*\)'
  message: 'zip must be used with strict=True'
  replacement_options:
  - description: Use strict=True
    pattern: 'zip\((.*)\)'
    replacement: 'zip(\1, strict=True)'

Text Replacement

Replace Enum with StrEnum/IntEnum

- pattern: 'class (\w+)\(Enum'
  message: 'Prefer StrEnum or IntEnum over Enum'
  replacement_options:
  - description: 'Use StrEnum'
    pattern: 'class (\w+)\(Enum'
    replacement: 'class \1(StrEnum'
    imports: [ from enum import StrEnum ]
  - description: 'Use IntEnum'
    pattern: 'class (\w+)\(Enum'
    replacement: 'class \1(IntEnum'
    imports: [ from enum import IntEnum ]

Text Replacement