Remove builtin exceptions brackets

Author: dflook

docs/source/transforms/remove_exception_brackets.rst

@@ -1,12 +1,12 @@
-Remove Exception Brackets
-=========================
+Remove Builtin Exception Brackets
+=================================
 
 This transform removes parentheses when raising builtin exceptions with no arguments.
 
 The raise statement automatically instantiates exceptions with no arguments, so the parentheses are unnecessary.
 
-This transform is enabled by default. Disable by passing the ``remove_exception_brackets=False`` argument to the :func:`python_minifier.minify` function,
-or passing ``--no-remove-exception-brackets`` to the pyminify command.
+This transform is enabled by default. Disable by passing the ``remove_builtin_exception_brackets=False`` argument to the :func:`python_minifier.minify` function,
+or passing ``--no-remove-builtin-exception-brackets`` to the pyminify command.
 
 Example
 -------

src/python_minifier/__init__.py

@@ -69,7 +69,7 @@ def minify(
     remove_asserts=False,
     remove_debug=False,
     remove_explicit_return_none=True,
-    remove_exception_brackets=True,
+    remove_builtin_exception_brackets=True
 ):
     """
     Minify a python module
@@ -101,7 +101,7 @@ def minify(
     :param bool remove_asserts: If assert statements should be removed
     :param bool remove_debug: If conditional statements that test '__debug__ is True' should be removed
     :param bool remove_explicit_return_none: If explicit return None statements should be replaced with a bare return
-    :param bool remove_exception_brackets: If brackets should be removed when raising exceptions with no arguments
+    :param bool remove_builtin_exception_brackets: If brackets should be removed when raising exceptions with no arguments
 
     :rtype: str
 
@@ -153,7 +153,7 @@ def minify(
     bind_names(module)
     resolve_names(module)
 
-    if remove_exception_brackets:
+    if remove_builtin_exception_brackets:
         remove_no_arg_exception_call(module)
 
     if module.tainted:

src/python_minifier/__init__.pyi

@@ -23,8 +23,8 @@ def minify(
     preserve_shebang: bool = ...,
     remove_asserts: bool = ...,
     remove_debug: bool = ...,
-    remove_explicit_return_none: bool = ...
-    remove_exception_brackets: bool = ...,
+    remove_explicit_return_none: bool = ...,
+    remove_builtin_exception_brackets: bool = ...
 ) -> Text: ...
 
 def unparse(module: ast.Module) -> Text: ...

src/python_minifier/__main__.py

@@ -185,9 +185,9 @@ def parse_args():
         dest='remove_explicit_return_none',
     )
     minification_options.add_argument(
-        '--no-remove-exception-brackets',
+        '--no-remove-builtin-exception-brackets',
         action='store_false',
-        help='Disable removing brackets when raising exceptions with no arguments',
+        help='Disable removing brackets when raising builtin exceptions with no arguments',
         dest='remove_exception_brackets',
     )
 
@@ -308,7 +308,7 @@ def do_minify(source, filename, minification_args):
         remove_asserts=minification_args.remove_asserts,
         remove_debug=minification_args.remove_debug,
         remove_explicit_return_none=minification_args.remove_explicit_return_none,
-        remove_exception_brackets=minification_args.remove_exception_brackets
+        remove_builtin_exception_brackets=minification_args.remove_exception_brackets
     )
 
 

src/python_minifier/transforms/remove_exception_brackets.py

@@ -120,3 +120,5 @@ def remove_no_arg_exception_call(module):
         if isinstance(binding, BuiltinBinding) and binding.name in builtin_exceptions:
             # We can remove any calls to builtin exceptions
             _remove_empty_call(binding)
+
+    return module

test/test_remove_exception_brackets.py

@@ -0,0 +1,109 @@
+import ast
+import sys
+
+import pytest
+
+from python_minifier.rename import add_namespace, bind_names, resolve_names
+from python_minifier.ast_compare import compare_ast
+from python_minifier.transforms.remove_exception_brackets import remove_no_arg_exception_call
+
+
+def remove_brackets(source):
+    module = ast.parse(source, 'remove_brackets')
+
+    add_namespace(module)
+    bind_names(module)
+    resolve_names(module)
+    return remove_no_arg_exception_call(module)
+
+
+def test_exception_brackets():
+    """This is a buitin so remove the brackets"""
+    source = 'def a(): raise Exception()'
+    expected = 'def a(): raise Exception'
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_zero_division_error_brackets():
+    """This is a buitin so remove the brackets"""
+    source = 'def a(): raise ZeroDivisionError()'
+    expected = 'def a(): raise ZeroDivisionError'
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_builtin_with_arg():
+    """This has an arg so dont' remove the brackets"""
+    source = 'def a(): raise Exception(1)'
+    expected = 'def a(): raise Exception(1)'
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_one_division_error_brackets():
+    """This is not a builtin so don't remove the brackets even though it's not defined in the module"""
+    source = 'def a(): raise OneDivisionError()'
+    expected = source
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_redefined():
+    """This is usually a builtin, but don't remove brackets if it's been redefined"""
+    source = '''
+def a():
+    raise ZeroDivisionError()
+def b():
+    ZeroDivisionError = blag
+    raise ZeroDivisionError()
+'''
+    expected = '''
+def a():
+    raise ZeroDivisionError
+def b():
+    ZeroDivisionError = blag
+    raise ZeroDivisionError()
+'''
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_raise_from():
+    """This is a builtin so remove the brackets"""
+    if sys.version_info < (3, 0):
+        pytest.skip('raise from not supported in this version of python')
+    source = 'def a(): raise Exception() from Exception()'
+    expected = 'def a(): raise Exception from Exception'
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_raise_from_only():
+    """This is a builtin so remove the brackets"""
+    if sys.version_info < (3, 0):
+        pytest.skip('raise from not supported in this version of python')
+
+    source = 'def a(): raise Hello() from Exception()'
+    expected = 'def a(): raise Hello() from Exception'
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)
+
+def test_raise_from_arg():
+    """This is a builtin so remove the brackets"""
+    if sys.version_info < (3, 0):
+        pytest.skip('raise from not supported in this version of python')
+
+    source = 'def a(): raise Hello() from Exception(1)'
+    expected = 'def a(): raise Hello() from Exception(1)'
+
+    expected_ast = ast.parse(expected)
+    actual_ast = remove_brackets(source)
+    compare_ast(expected_ast, actual_ast)