test with smaller call stack

Author: samuelcolvin

devtools/debug.py

@@ -1,5 +1,6 @@
 import ast
 import inspect
+import os
 import re
 import warnings
 from pathlib import Path
@@ -10,6 +11,10 @@
 CWD = Path('.').resolve()
 
 
+def env_true(var_name, alt='FALSE'):
+    return os.getenv(var_name, alt).upper() in {'1', 'TRUE'}
+
+
 class DebugArgument:
     __slots__ = 'value', 'name', 'extra'
 
@@ -64,14 +69,20 @@ def __repr__(self) -> str:
 
 class Debug:
     output_class = DebugOutput
-    # 50 lines should be enough to make sure we always get the entire function definition
-    frame_context_length = 50
     complex_nodes = (
         ast.Call, ast.Attribute,
         ast.IfExp, ast.BoolOp, ast.BinOp, ast.Compare,
         ast.DictComp, ast.ListComp, ast.SetComp, ast.GeneratorExp
     )
 
+    def __init__(self, *, warnings: Optional[bool]=None, frame_context_length: int=50):
+        if warnings is None:
+            self._warnings = env_true('PY_DEVTOOLS_WARNINGS', 'TRUE')
+        else:
+            self._warnings = warnings
+        # 50 lines should be enough to make sure we always get the entire function definition
+        self._frame_context_length = frame_context_length
+
     def __call__(self, *args, **kwargs):
         print(self._process(args, kwargs, r'debug *\('), flush=True)
 
@@ -80,7 +91,7 @@ def format(self, *args, **kwargs):
 
     def _process(self, args, kwargs, func_regex):
         curframe = inspect.currentframe()
-        frames = inspect.getouterframes(curframe, context=self.frame_context_length)
+        frames = inspect.getouterframes(curframe, context=self._frame_context_length)
         # BEWARE: this must be call by a method which in turn is called "directly" for the frame to be correct
         call_frame = frames[2]
 
@@ -102,7 +113,8 @@ def _process(self, args, kwargs, func_regex):
                 arguments = list(self._args_inspection_failed(args, kwargs))
         else:
             lineno = call_frame.lineno
-            warnings.warn('no code context for debug call, code inspection impossible', RuntimeWarning)
+            if self._warnings:
+                warnings.warn('no code context for debug call, code inspection impossible', RuntimeWarning)
             arguments = list(self._args_inspection_failed(args, kwargs))
 
         return self.output_class(
@@ -182,9 +194,15 @@ def _parse_code(self, call_frame, func_regex, filename) -> Tuple[Optional[ast.AS
                     break
 
             if not func_ast:
-                warnings.warn('error passing code:\n"{}"\nError: {}'.format(original_code, e1), SyntaxWarning)
+                if self._warnings:
+                    warnings.warn('error passing code:\n"{}"\nError: {}'.format(original_code, e1), SyntaxWarning)
                 return None, None, lineno
 
+        if not isinstance(func_ast, ast.Call):
+            if self._warnings:
+                warnings.warn('error passing code, found {} not Call'.format(func_ast.__class__), SyntaxWarning)
+            return None, None, lineno
+
         code_lines = [l for l in code.split('\n') if l]
         # this removes the trailing bracket from the lines of code meaning it doesn't appear in the
         # representation of the last argument

setup.cfg

@@ -8,7 +8,7 @@ filterwarnings =
 
 [flake8]
 max-line-length = 120
-max-complexity = 10
+max-complexity = 12
 
 [bdist_wheel]
 python-tag = py35,py36

tests/test_expr_render.py

@@ -3,7 +3,7 @@
 
 import pytest
 
-from devtools import debug
+from devtools import Debug, debug
 
 
 def foobar(a, b, c):
@@ -167,3 +167,22 @@ def test_syntax_warning():
     assert (
         'tests/test_expr_render.py:<line no> test_syntax_warning: 1 (int)'
     ) == s
+
+
+def test_no_syntax_warning():
+    # exceed the 4 extra lines which are normally checked
+    debug_ = Debug(warnings=False)
+    with pytest.warns(None) as warning_checker:
+        v = debug_.format(
+            abs(
+                abs(
+                    abs(
+                        abs(
+                            -1
+                        )
+                    )
+                )
+            )
+        )
+        assert 'test_no_syntax_warning: 1 (int)' in str(v)
+    assert len(warning_checker) == 0

tests/test_main.py

@@ -5,7 +5,7 @@
 
 import pytest
 
-from devtools import debug
+from devtools import Debug, debug
 
 
 def test_print(capsys):
@@ -63,6 +63,45 @@ def test_func(v):
     )
 
 
+def test_odd_path(mocker):
+    # all valid calls
+    mocked_relative_to = mocker.patch('pathlib.Path.relative_to')
+    mocked_relative_to.side_effect = ValueError()
+    v = debug.format('test')
+    assert re.search('/.*?/test_main.py:\d{2,} test_odd_path: "test" \(str\) len=4', str(v)), v
+
+
+def test_small_call_frame():
+    debug_ = Debug(warnings=False, frame_context_length=2)
+    v = debug_.format(
+        1,
+        2,
+        3,
+    )
+    assert re.sub(':\d{2,}', ':<line no>', str(v)) == (
+        'tests/test_main.py:<line no> test_small_call_frame\n'
+        '  1 (int)\n'
+        '  2 (int)\n'
+        '  3 (int)'
+    )
+
+
+def test_small_call_frame_warning():
+    debug_ = Debug(frame_context_length=2)
+    with pytest.warns(SyntaxWarning):
+        v = debug_.format(
+            1,
+            2,
+            3,
+        )
+    assert re.sub(':\d{2,}', ':<line no>', str(v)) == (
+        'tests/test_main.py:<line no> test_small_call_frame_warning\n'
+        '  1 (int)\n'
+        '  2 (int)\n'
+        '  3 (int)'
+    )
+
+
 @pytest.mark.skipif(sys.version_info < (3, 6), reason='kwarg order is not guaranteed for 3.5')
 def test_kwargs():
     a = 'variable'
@@ -122,6 +161,16 @@ def test_eval():
     assert str(v) == '<string>:1 <module>: 1 (int)'
 
 
+def test_warnings_disabled():
+    debug_ = Debug(warnings=False)
+    with pytest.warns(None) as warnings:
+        v1 = eval('debug_.format(1)')
+        assert str(v1) == '<string>:1 <module>: 1 (int)'
+        v2 = debug_.format(1)
+        assert 'test_warnings_disabled: 1 (int)' in str(v2)
+    assert len(warnings) == 0
+
+
 @pytest.mark.skipif(sys.version_info < (3, 6), reason='kwarg order is not guaranteed for 3.5')
 def test_eval_kwargs():
     with pytest.warns(RuntimeWarning):