pi-lens/rules/tree-sitter-queries/python/send-file-mimetype.yml

Real-time code feedback for pi — LSP, linters, formatters, type-checking, structural analysis & booboo

# Send File Mimetype
# Detects send_file without mimetype or download_name
id: send-file-mimetype
name: send_file Should Specify Mimetype or Download Name
severity: error
category: reliability
defect_class: correctness
inline_tier: blocking
language: python

message: "send_file should specify 'mimetype' or 'download_name' when used with file-like objects"

description: |
  Flask's send_file without mimetype or download_name can cause
  security issues and incorrect browser handling. Always specify
  at least one when sending files.

  ✅ FIX: Add mimetype or download_name parameter

  ```python
  send_file(file_obj, mimetype='text/plain')  # GOOD
  send_file(file_obj, download_name='report.pdf')  # GOOD
  ```

query: |
  (call
    function: (identifier) @FUNC (#eq? @FUNC "send_file")
    arguments: (argument_list
      (_) @FIRST_ARG
      (keyword_argument)? @KW))

metavars:
  - FUNC
  - FIRST_ARG
  - KW

post_filter: missing_mimetype_and_download_name

tags:
  - reliability
  - python
  - flask
  - security

examples:
  bad: |
    send_file(file_obj)  # BAD - missing mimetype and download_name

  good: |
    send_file(file_obj, mimetype='application/pdf')  # GOOD
    send_file(file_obj, download_name='report.pdf')  # GOOD

has_fix: false