Add feature to enable debugging on uncaught exceptions.

kdart · thomasballinger · commit b37d832f454e · 2015-04-13T15:05:47.000-04:00
Also add pretty-printng option.
The debugger is selected by an environment variable.
diff --git a/bpython/args.py b/bpython/args.py
@@ -74,6 +74,10 @@ def parse(args, extras=None, ignore_stdin=False):
                       help=_("Don't flush the output to stdout."))
     parser.add_option('--version', '-V', action='store_true',
                       help=_('Print version and exit.'))
+    parser.add_option('--pretty', '-p', action='store_true',
+                      help=_('Pretty print output.'))
+    parser.add_option('--debugger', '-D', action='store_true',
+                      help=_('Enter a debugger on exceptions.'))
 
     if extras is not None:
         extras_group = OptionGroup(parser, extras[0], extras[1])
diff --git a/bpython/cli.py b/bpython/cli.py
@@ -49,6 +49,7 @@
 import re
 import time
 import functools
+from pprint import pprint
 
 import struct
 if platform.system() != 'Windows':
@@ -160,6 +161,7 @@ def __init__(self, interface):
         self.encoding = getpreferredencoding()
         self.interface = interface
         self.buffer = list()
+        self.errors = "strict"
 
     def __iter__(self):
         return iter(self.readlines())
@@ -957,6 +959,13 @@ def p_key(self, key):
             self.write2file()
             return ''
 
+        elif key in key_dispatch[config.debug_key]:
+            if sys.excepthook is not debugger_hook:
+                sys.excepthook = debugger_hook
+            else:
+                sys.excepthook = sys.__excepthook__
+            return ''
+
         elif key in key_dispatch[config.pastebin_key]:
             self.pastebin()
             return ''
@@ -1696,7 +1705,8 @@ def init_wins(scr, config):
         (_('Save'), config.save_key),
         (_('Pastebin'), config.pastebin_key),
         (_('Pager'), config.last_output_key),
-        (_('Show Source'), config.show_source_key)
+        (_('Show Source'), config.show_source_key),
+        (_('Auto Debug'), config.debug_key),
     )
 
     message = '  '.join('<%s> %s' % (key, command) for command, key in commands
@@ -1944,17 +1954,59 @@ def main_curses(scr, args, config, interactive=True, locals_=None,
     return (exit_value, clirepl.getstdout())
 
 
+def prettydisplayhook(obj):
+    pprint(obj)
+
+
+def debugger_hook(exc, value, tb):
+
+    if exc in (SyntaxError, IndentationError, KeyboardInterrupt):
+        sys.__excepthook__(exc, value, tb)
+        return
+
+    global stdscr
+    from bpython import debugger
+
+    orig_stdin = sys.stdin
+    orig_stdout = sys.stdout
+    orig_stderr = sys.stderr
+
+    sys.stdin = sys.__stdin__
+    sys.stderr = sys.__stderr__
+    sys.stdout = sys.__stdout__
+
+    stdscr.keypad(0)
+    curses.echo()
+    curses.nocbreak()
+    curses.endwin()
+    try:
+        debugger.post_mortem(tb, exc, value)
+    finally:
+        sys.stdin = orig_stdin
+        sys.stdout = orig_stdout
+        sys.stderr = orig_stderr
+        curses.cbreak()
+        curses.noecho()
+        stdscr.keypad(1)
+        if stdscr is None:
+            stdscr = curses.initscr()
+
+
 def main(args=None, locals_=None, banner=None):
     translations.init()
 
-
     config, options, exec_args = bpython.args.parse(args)
 
     # Save stdin, stdout and stderr for later restoration
     orig_stdin = sys.stdin
     orig_stdout = sys.stdout
     orig_stderr = sys.stderr
 
+    if options.debugger:
+        sys.excepthook = debugger_hook
+    if options.pretty:
+        sys.displayhook = prettydisplayhook
+
     try:
         (exit_value, output) = curses_wrapper(
             main_curses, exec_args, config, options.interactive, locals_,
diff --git a/bpython/config.py b/bpython/config.py
@@ -122,7 +122,8 @@ def loadini(struct, configfile):
             'transpose_chars': 'C-t',
             'undo': 'C-r',
             'up_one_line': 'C-p',
-            'yank_from_buffer': 'C-y'
+            'yank_from_buffer': 'C-y',
+            'debug': 'F12',
         },
         'cli': {
             'suggestion_width': 0.8,
@@ -211,6 +212,7 @@ def get_key_no_doublebind(command):
     struct.edit_current_block_key = get_key_no_doublebind('edit_current_block')
     struct.external_editor_key = get_key_no_doublebind('external_editor')
     struct.help_key = get_key_no_doublebind('help')
+    struct.debug_key = get_key_no_doublebind('debug')
 
     struct.pastebin_confirm = config.getboolean('general', 'pastebin_confirm')
     struct.pastebin_url = config.get('general', 'pastebin_url')
diff --git a/bpython/debugger.py b/bpython/debugger.py
@@ -0,0 +1,36 @@
+#!/usr/bin/python2.7
+# -*- coding: utf-8 -*-
+# vim:ts=4:sw=4:softtabstop=4:smarttab:expandtab
+
+"""
+Debugger factory. Set PYTHON_DEBUGGER to a module path that has a post_mortem
+function in it. Defaults to pdb. This allows alternate debuggers to be used,
+such as pycopia.debugger. :)
+"""
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+from __future__ import division
+
+
+import os
+import sys
+
+
+post_mortem = None
+
+def _get_debugger():
+    global post_mortem
+    modname = os.environ.get("PYTHON_DEBUGGER", "pdb")
+    __import__(modname)
+    mod = sys.modules[modname]
+    pm = getattr(mod, "post_mortem")
+    if pm.__code__.co_argcount > 2:
+        post_mortem = pm
+    else:
+        def _post_mortem(t, ex, exval):
+            return pm(t)
+        post_mortem = _post_mortem
+
+_get_debugger()
+
diff --git a/bpython/repl.py b/bpython/repl.py
@@ -159,9 +159,15 @@ def showtraceback(self):
                 l.insert(0, "Traceback (most recent call last):\n")
             l[len(l):] = traceback.format_exception_only(t, v)
         finally:
-            tblist = tb = None
+            tblist = None
+        # If someone has set sys.excepthook, we let that take precedence
+        # over self.write
+        if sys.excepthook is sys.__excepthook__:
+            tb = None
+            self.writetb(l)
+        else:
+            sys.excepthook(t, v, tb)
 
-        self.writetb(l)
 
     def writetb(self, lines):
         """This outputs the traceback and should be overridden for anything
