Fallback to basic Source.pieces when there is no Source.tree. Fixes #21

setup.cfg

@@ -27,7 +27,7 @@ include_package_data = True
 tests_require = pytest; typeguard; pygments; littleutils
 
 [options.extras_require]
-tests = pytest; typeguard; pygments; littleutils
+tests = pytest; typeguard; pygments; littleutils; cython
 
 [coverage:run]
 relative_files = True

stack_data/core.py

@@ -83,7 +83,10 @@ def __init__(self, *args, **kwargs):
     @cached_property
     def pieces(self) -> List[range]:
         if not self.tree:
-            raise AttributeError("This file doesn't contain valid Python, so .pieces doesn't exist")
+            return [
+                range(i, i + 1)
+                for i in range(1, len(self.lines) + 1)
+            ]
         return list(self._clean_pieces())
 
     @cached_property
@@ -352,7 +355,7 @@ def render(
         If strip_leading_indent is true (the default) then leading spaces
         common to all lines in this frame will be excluded.
         """
-        if pygmented:
+        if pygmented and self.frame_info.scope:
             assert_(not markers, ValueError("Cannot use pygmented with markers"))
             start_line, lines = self.frame_info._pygmented_scope_lines
             result = lines[self.lineno - start_line]
@@ -569,10 +572,12 @@ def _frame_key(x):
     @cached_property
     def scope_pieces(self) -> List[range]:
         """
-        All the pieces (ranges of lines) contained in this object's .scope.
+        All the pieces (ranges of lines) contained in this object's .scope,
+        unless there is no .scope (because the source isn't valid Python syntax)
+        in which case it returns all the pieces in the source file, each containing one line.
         """
         if not self.scope:
-            return []
+            return self.source.pieces
 
         scope_start, scope_end = line_range(self.scope)
         return [
@@ -619,9 +624,6 @@ def executing_piece(self) -> range:
         """
         The piece (range of lines) containing the line currently being executed
         by the interpreter in this frame.
-
-        Raises an exception if .scope is None, which usually means the source code
-        for this frame is unavailable.
         """
         return only(
             piece
@@ -701,6 +703,7 @@ def lines(self) -> List[Union[Line, LineGap]]:
         for i, piece in enumerate(pieces):
             if (
                     i == 1
+                    and self.scope
                     and pieces[0] == self.scope_pieces[0]
                     and pieces[1] != self.scope_pieces[1]
             ):

tests/__init__.py

@@ -1,5 +1,9 @@
 import os
+
+import pyximport
 from typeguard.importhook import install_import_hook
 
+pyximport.install()
+
 if not os.environ.get("STACK_DATA_SLOW_TESTS"):
     install_import_hook(["stack_data"])

tests/golden_files/cython_example.txt

@@ -0,0 +1,11 @@
+Traceback (most recent call last):
+ File "cython_example.pyx", line 2, in tests.samples.cython_example.foo
+       1 | def foo():
+-->    2 |     bar()
+       3 | 
+ File "cython_example.pyx", line 5, in tests.samples.cython_example.bar
+       2 |     bar()
+       3 | 
+       4 | cdef bar():
+-->    5 |     raise ValueError("bar!")
+ValueError: bar!

tests/samples/cython_example.pyx

@@ -0,0 +1,5 @@
+def foo():
+    bar()
+
+cdef bar():
+    raise ValueError("bar!")

tests/test_core.py

@@ -534,7 +534,6 @@ def test_invalid_source():
     filename = str(samples_dir / "not_code.txt")
     source = Source.for_filename(filename)
     assert not source.tree
-    assert not hasattr(source, "pieces")
     assert not hasattr(source, "tokens_by_lineno")
 
 

tests/test_formatter.py

@@ -21,7 +21,7 @@ def format_variable_value(self, value) -> str:
 
 class MyFormatter(BaseFormatter):
     def format_frame(self, frame):
-        if not frame.filename.endswith(("formatter_example.py", "<string>")):
+        if not frame.filename.endswith(("formatter_example.py", "<string>", "cython_example.pyx")):
             return
         yield from super().format_frame(frame)
 
@@ -72,3 +72,11 @@ def check_example(name):
             f_string()
         except Exception:
             MyFormatter().print_exception()
+
+    from .samples import cython_example
+
+    with check_example("cython_example"):
+        try:
+            cython_example.foo()
+        except Exception:
+            MyFormatter().print_exception()