Add testing for exceptions

tests/test_chinese.py

@@ -16,7 +16,8 @@ from pysnooper import pycompat
 from pysnooper.variables import needs_parentheses
 from .utils import (assert_output, assert_sample_output, VariableEntry,
                     CallEntry, LineEntry, ReturnEntry, OpcodeEntry,
-                    ReturnValueEntry, ExceptionEntry, SourcePathEntry,
+                    ReturnValueEntry, ExceptionEntry, ExceptionValueEntry,
+                    SourcePathEntry, CallEndedByExceptionEntry,
                     ElapsedTimeEntry)
 from . import mini_toolbox
 

tests/test_multiple_files/test_multiple_files.py

@@ -15,7 +15,8 @@ import pysnooper
 from pysnooper.variables import needs_parentheses
 from ..utils import (assert_output, assert_sample_output, VariableEntry,
                     CallEntry, LineEntry, ReturnEntry, OpcodeEntry,
-                    ReturnValueEntry, ExceptionEntry, SourcePathEntry,
+                    ReturnValueEntry, ExceptionEntry, ExceptionValueEntry,
+                    SourcePathEntry, CallEndedByExceptionEntry,
                     ElapsedTimeEntry)
 from .. import mini_toolbox
 from .multiple_files import foo

tests/test_not_implemented.py

@@ -17,7 +17,9 @@ from pysnooper.variables import needs_parentheses
 from pysnooper import pycompat
 from .utils import (assert_output, assert_sample_output, VariableEntry,
                     CallEntry, LineEntry, ReturnEntry, OpcodeEntry,
-                    ReturnValueEntry, ExceptionEntry, SourcePathEntry)
+                    ReturnValueEntry, ExceptionEntry, ExceptionValueEntry,
+                    SourcePathEntry, CallEndedByExceptionEntry,
+                    ElapsedTimeEntry)
 from . import mini_toolbox
 
 

tests/test_pysnooper.py

@@ -16,7 +16,8 @@ import pysnooper
 from pysnooper.variables import needs_parentheses
 from .utils import (assert_output, assert_sample_output, VariableEntry,
                     CallEntry, LineEntry, ReturnEntry, OpcodeEntry,
-                    ReturnValueEntry, ExceptionEntry, SourcePathEntry,
+                    ReturnValueEntry, ExceptionEntry, ExceptionValueEntry,
+                    SourcePathEntry, CallEndedByExceptionEntry,
                     ElapsedTimeEntry)
 from . import mini_toolbox
 
@@ -1864,3 +1865,34 @@ def test_normalize_thread_info():
 
     with pytest.raises(NotImplementedError):
         add()
+
+
+def test_exception():
+    string_io = io.StringIO()
+    @pysnooper.snoop(string_io)
+    def f():
+        x = 8
+        raise MemoryError
+
+    with pytest.raises(MemoryError):
+        f()
+
+    output = string_io.getvalue()
+    assert_output(
+        output,
+        (
+            SourcePathEntry(),
+            CallEntry(),
+            LineEntry(),
+            VariableEntry(),
+            LineEntry(),
+            ExceptionEntry(),
+            ExceptionValueEntry('MemoryError'),
+            CallEndedByExceptionEntry(),
+            ElapsedTimeEntry(),
+        )
+    )
+
+
+
+

tests/utils.py

@@ -101,6 +101,19 @@ class ElapsedTimeEntry(_BaseEntry):
 
 
 
+class CallEndedByExceptionEntry(_BaseEntry):
+    # Todo: Looking at this class, we could rework the hierarchy.
+    def __init__(self, prefix=''):
+        _BaseEntry.__init__(self, prefix=prefix)
+
+    def check(self, s):
+        return re.match(
+            r'''(?P<indent>(?: {4})*)Call ended by exception''',
+            s
+        )
+
+
+
 class VariableEntry(_BaseValueEntry):
     def __init__(self, name=None, value=None, stage=None, prefix='',
                  name_regex=None, value_regex=None):
@@ -165,7 +178,7 @@ class VariableEntry(_BaseValueEntry):
             return stage == self.stage
 
 
-class ReturnValueEntry(_BaseValueEntry):
+class _BaseSimpleValueEntry(_BaseValueEntry):
     def __init__(self, value=None, value_regex=None, prefix=''):
         _BaseValueEntry.__init__(self, prefix=prefix)
         if value is not None:
@@ -175,10 +188,6 @@ class ReturnValueEntry(_BaseValueEntry):
         self.value_regex = (None if value_regex is None else
                             re.compile(value_regex))
 
-    _preamble_pattern = re.compile(
-        r"""^Return value$"""
-    )
-
     def _check_preamble(self, preamble):
         return bool(self._preamble_pattern.match(preamble))
 
@@ -193,6 +202,16 @@ class ReturnValueEntry(_BaseValueEntry):
         else:
             return True
 
+class ReturnValueEntry(_BaseSimpleValueEntry):
+    _preamble_pattern = re.compile(
+        r"""^Return value$"""
+    )
+
+class ExceptionValueEntry(_BaseSimpleValueEntry):
+    _preamble_pattern = re.compile(
+        r"""^Exception$"""
+    )
+
 class SourcePathEntry(_BaseValueEntry):
     def __init__(self, source_path=None, source_path_regex=None, prefix=''):
         _BaseValueEntry.__init__(self, prefix=prefix)
@@ -315,6 +334,8 @@ def verify_normalize(lines, prefix):
 
 def assert_output(output, expected_entries, prefix=None, normalize=False):
     lines = tuple(filter(None, output.split('\n')))
+    if expected_entries and not lines:
+        raise OutputFailure("Output is empty")
 
     if prefix is not None:
         for line in lines: