mcp-server-semgrep/semgrep-rules/python/lang/maintainability/improper-list-concat.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
  - id: improper-list-concat
    languages:
      - python
    message: >-
      This expression will evaluate to be ONLY value the of the `else` clause if the
      condition `$EXPRESSION`
      is false. If you meant to do list concatenation, put parentheses around the entire
      concatenation expression, like
      this: `['a', 'b', 'c'] + (['d'] if x else ['e'])`. If this is the intended behavior,
      the expression may be confusing to
      others, and you may wish to add parentheses for readability.
    metadata:
      category: maintainability
      technology:
        - python
    pattern: "[...] + [...] if $EXPRESSION else [...]"
    severity: INFO