About

AST Transformer integrated with py.test.

Useful for debug, refactoring, 'clean asserts' (see examples/replace_asserts)

Support options

Options	Description
--show-code	show generated code
--disable-transforms	disable all ast transformers

Install

pip install pytest-ast-transformer

Usage

• Write ast transformer

  # transformer.py
  import ast
  
  from pytest_ast_transformer.ast_transformer import PytestTransformer
  
  
  def my_assert(test_result, msg=''):
      print(f'my assert: {test_result} {msg}')
      assert test_result, msg
  
  
  class AssertTransformer(PytestTransformer):
      context = {
          'my_assert': my_assert
      }
  
      def visit_Assert(self, node: ast.Assert) -> ast.Expr:
          func_name = ast.Name(id='my_assert', ctx=ast.Load())
          call_func = ast.Call(func=func_name, args=[node.test, node.msg], keywords=[])
          expr = ast.Expr(value=call_func)
  
          return ast.fix_missing_locations(expr)

• Register new ast transformer

  # conftest.py
  from pytest_ast_transformer.ast_manager import ASTManager
  from tests.transformer import AssertTransformer
  
  
  def pytest_register_ast_transformer(ast_manager: ASTManager):
      ast_manager.add_transformer(AssertTransformer())