Simplify detail formatting and 100% coverage.

3 files changed, 35 insertions, 13 deletions

diff --git a/src/zope/configuration/config.py b/src/zope/configuration/config.py
index 643ff2c..6ce6d06 100644
--- a/src/zope/configuration/config.py
+++ b/src/zope/configuration/config.py
@@ -727,7 +727,7 @@ class ConfigurationMachine(ConfigurationAdapterRegistry, ConfigurationContext):
             [('f', (1,), {}), ('f', (2,), {})]
 
         If the action raises an error, we convert it to a
-        ConfigurationExecutionError.
+        `ConfigurationExecutionError`.
 
             >>> from zope.configuration.config import ConfigurationExecutionError
             >>> output = []
@@ -750,6 +750,24 @@ class ConfigurationMachine(ConfigurationAdapterRegistry, ConfigurationContext):
 
             >>> output
             [('f', (1,), {}), ('f', (2,), {})]
+
+        If the exception was already a `ConfigurationError`, it is raised
+        as-is with the action's ``info`` added.
+
+            >>> def bad():
+            ...     raise ConfigurationError("I'm bad")
+            >>> context.actions = [
+            ...   (1, f, (1,)),
+            ...   (1, f, (11,), {}, ('x', )),
+            ...   (2, f, (2,)),
+            ...   (3, bad, (), {}, (), 'oops')
+            ...   ]
+            >>> context.execute_actions()
+            Traceback (most recent call last):
+            ...
+            zope.configuration.exceptions.ConfigurationError: I'm bad
+                oops
+
         """
         pass_through_exceptions = self.pass_through_exceptions
         if testing:
@@ -765,7 +783,7 @@ class ConfigurationMachine(ConfigurationAdapterRegistry, ConfigurationContext):
                 try:
                     callable(*args, **kw)
                 except ConfigurationError as ex:
-                    ex.append_details(info)
+                    ex.add_details(info)
                     raise
                 except pass_through_exceptions:
                     raise
@@ -1660,7 +1678,7 @@ def toargs(context, schema, data):
             try:
                 args[str(name)] = field.fromUnicode(s)
             except ValidationError as v:
-                reraise(ConfigurationError("Invalid value for %r: %r" % (n, v)).append_details(v),
+                reraise(ConfigurationError("Invalid value for %r: %r" % (n, v)).add_details(v),
                         None, sys.exc_info()[2])
         elif field.required:
             # if the default is valid, we can use that:
diff --git a/src/zope/configuration/exceptions.py b/src/zope/configuration/exceptions.py
index 1262035..abac17a 100644
--- a/src/zope/configuration/exceptions.py
+++ b/src/zope/configuration/exceptions.py
@@ -26,9 +26,11 @@ class ConfigurationError(Exception):
 
     # A list of strings or things that can be converted to strings,
     # added by append_details as we walk back up the call/include stack.
+    # We will print them in reverse order so that the most recent detail is
+    # last.
     _details = ()
 
-    def append_details(self, info):
+    def add_details(self, info):
         if isinstance(info, BaseException):
             info = traceback.format_exception_only(type(info), info)
             # Trim trailing newline
@@ -38,17 +40,19 @@ class ConfigurationError(Exception):
             self._details += (info,)
         return self
 
+    def _with_details(self, opening, detail_formatter):
+        lines = ['    ' + detail_formatter(detail) for detail in self._details]
+        lines.append(opening)
+        lines.reverse()
+        return '\n'.join(lines)
+
     def __str__(self):
         s = super(ConfigurationError, self).__str__()
-        for i in self._details:
-            s += '\n    ' + str(i)
-        return s
+        return self._with_details(s, str)
 
     def __repr__(self):
         s = super(ConfigurationError, self).__repr__()
-        for i in self._details:
-            s += '\n    ' + repr(i)
-        return s
+        return self._with_details(s, repr)
 
 
 class ConfigurationWrapperError(ConfigurationError):
@@ -57,7 +61,7 @@ class ConfigurationWrapperError(ConfigurationError):
 
     def __init__(self, info, exception):
         super(ConfigurationWrapperError, self).__init__(repr(info) if self.USE_INFO_REPR else info)
-        self.append_details(exception)
+        self.add_details(exception)
 
         # This stuff is undocumented and not used but we store
         # for backwards compatibility
diff --git a/src/zope/configuration/xmlconfig.py b/src/zope/configuration/xmlconfig.py
index b12b091..4fc0d0d 100644
--- a/src/zope/configuration/xmlconfig.py
+++ b/src/zope/configuration/xmlconfig.py
@@ -228,7 +228,7 @@ class ConfigurationHandler(ContentHandler):
         if self.testing:
             raise
         if isinstance(ex, ConfigurationError):
-            ex.append_details(repr(info))
+            ex.add_details(repr(info))
             raise
 
         exc = ZopeXMLConfigurationError(info, ex)
@@ -406,7 +406,7 @@ def processxmlfile(file, context, testing=False):
     try:
         parser.parse(src)
     except SAXParseException:
-        reraise(ZopeSAXParseException(src, sys.exc_info()[1]),
+        reraise(ZopeSAXParseException(file, sys.exc_info()[1]),
                 None, sys.exc_info()[2])