add the ability to convert parsed exceptions back into strings, as well as split out testing for the parsed exception

boltons/tbutils.py

@@ -682,6 +682,22 @@ class ParsedException(object):
         return ('%s(%r, %r, frames=%r)'
                 % (cn, self.exc_type, self.exc_msg, self.frames))
 
+    def to_string(self):
+        lines = [u'Traceback (most recent call last):']
+
+        for frame in self.frames:
+            lines.append(u'  File "%s", line %s, in %s' % (frame['filepath'],
+                                                           frame['lineno'],
+                                                           frame['funcname']))
+            source_line = frame.get('source_line')
+            if source_line:
+                lines.append(u'    %s' % (source_line,))
+        if self.exc_msg:
+            lines.append(u'%s: %s' % (self.exc_type, self.exc_msg))
+        else:
+            lines.append(u'%s' % (self.exc_type,))
+        return u'\n'.join(lines)
+
     @classmethod
     def from_string(cls, tb_str):
         """Parse a traceback and exception from the text *tb_str*. This text

tests/test_tbutils.py

@@ -9,30 +9,12 @@ except:
 
 from boltons.tbutils import (TracebackInfo,
                              ExceptionInfo,
-                             ParsedException,
                              print_exception,
                              fix_print_exception,
                              ContextualCallpoint,
                              ContextualExceptionInfo)
 
 
-def test_parsed_exc():
-    FAKE_TB_STR = u"""
-Traceback (most recent call last):
-  File "example.py", line 2, in <module>
-    plarp
-NameError: name 'plarp' is not defined
-"""
-    parsed_tb = ParsedException.from_string(FAKE_TB_STR)
-    print(parsed_tb)
-    assert parsed_tb.exc_type == 'NameError'
-    assert parsed_tb.exc_msg == "name 'plarp' is not defined"
-    assert parsed_tb.frames == [{'source_line': u'plarp',
-                                 'filepath': u'example.py',
-                                 'lineno': u'2',
-                                 'funcname': u'<module>'}]
-
-
 
 def test_exception_info():
     # test ExceptionInfo and TracebackInfo and hooks, via StringIOs

tests/test_tbutils_parsed_exc.py

@@ -0,0 +1,53 @@
+
+from boltons.tbutils import ParsedException
+
+
+def test_parsed_exc_basic():
+    _tb_str = u"""\
+Traceback (most recent call last):
+  File "example.py", line 2, in <module>
+    plarp
+NameError: name 'plarp' is not defined"""
+
+    parsed_tb = ParsedException.from_string(_tb_str)
+    print(parsed_tb)
+    assert parsed_tb.exc_type == 'NameError'
+    assert parsed_tb.exc_msg == "name 'plarp' is not defined"
+    assert parsed_tb.frames == [{'source_line': u'plarp',
+                                 'filepath': u'example.py',
+                                 'lineno': u'2',
+                                 'funcname': u'<module>'}]
+
+    assert parsed_tb.to_string() == _tb_str
+
+
+def test_parsed_exc_nosrcline():
+    """just making sure that everything can be parsed even if there is
+    a line without source and also if the exception has no message"""
+
+    _tb_str = u"""\
+Traceback (most recent call last):
+  File "/home/mahmoud/virtualenvs/chert/bin/chert", line 9, in <module>
+    load_entry_point('chert==0.2.1.dev0', 'console_scripts', 'chert')()
+  File "/home/mahmoud/projects/chert/chert/core.py", line 1281, in main
+    ch.process()
+  File "/home/mahmoud/projects/chert/chert/core.py", line 741, in process
+    self.load()
+  File "<boltons.FunctionBuilder-0>", line 2, in load
+  File "/home/mahmoud/projects/lithoxyl/lithoxyl/logger.py", line 291, in logged_func
+    return func_to_log(*a, **kw)
+  File "/home/mahmoud/projects/chert/chert/core.py", line 775, in load
+    raise RuntimeError
+RuntimeError"""
+
+    parsed_tb = ParsedException.from_string(_tb_str)
+
+    assert parsed_tb.exc_type == 'RuntimeError'
+    assert parsed_tb.exc_msg == ''
+
+    assert len(parsed_tb.frames) == 6
+    assert parsed_tb.frames[3] == {'source_line': u'',
+                                   'filepath': u'<boltons.FunctionBuilder-0>',
+                                   'lineno': u'2',
+                                   'funcname': u'load'}
+    assert parsed_tb.to_string() == _tb_str