Improved debugging

1 files changed, 17 insertions, 0 deletions

diff --git a/coverage/debug.py b/coverage/debug.py
index d63a9070..fd27c731 100644
--- a/coverage/debug.py
+++ b/coverage/debug.py
@@ -31,6 +31,8 @@ _TEST_NAME_FILE = ""    # "/tmp/covtest.txt"
 class DebugControl(object):
     """Control and output for debugging."""
 
+    show_repr_attr = False      # For SimpleRepr
+
     def __init__(self, options, output):
         """Configure the options and output file for debugging."""
         self.options = list(options) + FORCED_DEBUG
@@ -71,6 +73,10 @@ class DebugControl(object):
         `msg` is the line to write. A newline will be appended.
 
         """
+        if self.should('self'):
+            caller_self = inspect.stack()[1][0].f_locals.get('self')
+            if caller_self is not None:
+                msg = "[self: {!r}] {}".format(caller_self, msg)
         self.output.write(msg+"\n")
         if self.should('callers'):
             dump_stack_frames(out=self.output, skip=1)
@@ -167,6 +173,17 @@ def add_pid_and_tid(text):
     return text
 
 
+class SimpleRepr(object):
+    """A mixin implementing a simple __repr__."""
+    def __repr__(self):
+        show_attrs = ((k, v) for k, v in self.__dict__.items() if getattr(v, "show_repr_attr", True))
+        return "<{klass} @0x{id:x} {attrs}>".format(
+            klass=self.__class__.__name__,
+            id=id(self),
+            attrs=" ".join("{}={!r}".format(k, v) for k, v in show_attrs),
+            )
+
+
 def filter_text(text, filters):
     """Run `text` through a series of filters.