Merge pull request #45 from apiaryio/wvi/exceptions

Attempt to improve exception handling of ValueError

Author: w-vi

dredd_hooks/dredd.py

@@ -109,12 +109,18 @@ def handle(self):
                     self.wfile.write(msg.encode('utf-8'))
                 else:
                     self.wfile.write(msg)
-        except ValueError:
-            print("\nConnection closed\n", file=sys.stderr)
-        except Exception:
-            traceback.print_exc(file=sys.stderr)
-            sys.stderr.flush()
-            raise
+
+        except Exception as e:
+            if sys.version_info[0] > 2 and isinstance(e, json.JSONDecodeError):
+                print('Connection closed, could not parse JSON',
+                      file=sys.stderr)
+            elif str(e) == "No JSON object could be decoded":
+                print('Connection closed, could not parse JSON',
+                      file=sys.stderr)
+            else:
+                traceback.print_exc(file=sys.stderr)
+                sys.stderr.flush()
+                raise
 
 
 def add_named_hook(obj, hook, name):

test/test_dredd_hooks.py

@@ -26,7 +26,6 @@ def __init__(self):
 
     def writeline(self, msg):
         msg = msg + hooks.MESSAGE_DELIMITER
-        print("%d" % (sys.version_info[0]))
         if sys.version_info[0] > 2:
             self.wfile.write(msg.encode('utf-8'))
         else:

test/test_excepts_hook.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+from __future__ import print_function
+import unittest
+import sys
+import socket
+import os
+import json
+import threading
+import time
+import dredd_hooks as hooks
+if sys.version_info[0] > 2:
+    import io
+else:
+    import StringIO as io
+
+hooks_thr = None
+
+
+class Connection(object):
+
+    def __init__(self):
+        self.connection = socket.create_connection((hooks.HOST, hooks.PORT))
+        self.rfile = self.connection.makefile('rb', -1)  # buffered input
+        self.wfile = self.connection.makefile('wb', 0)  # unbuffered output
+
+    def writeline(self, msg):
+        msg = msg + hooks.MESSAGE_DELIMITER
+        if sys.version_info[0] > 2:
+            self.wfile.write(msg.encode('utf-8'))
+        else:
+            self.wfile.write(msg)
+
+    def readline(self):
+        if sys.version_info[0] > 2:
+            return self.rfile.readline().decode('utf-8').strip()
+        else:
+            return self.rfile.readline().strip()
+
+    def close(self):
+        self.rfile.close()
+        self.wfile.close()
+        self.connection.close()
+
+
+class TestValueError(unittest.TestCase):
+    """
+    Tests exception handling.
+    """
+    @classmethod
+    def setUpClass(cls):
+        cls.output = io.StringIO()
+        cls.saved_stderr = sys.stderr
+        sys.stderr = cls.output
+        cls.hooks_thr = threading.Thread(target=hooks.main,
+                                         args=([os.path.abspath(__file__)],))
+        cls.hooks_thr.start()
+        time.sleep(1)
+        cls.conn = Connection()
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.output.close()
+        sys.stderr = cls.saved_stderr
+        cls.conn.close()
+        hooks.shutdown()
+        cls.hooks_thr.join()
+
+    def setUp(self):
+        self.conn.writeline(json.dumps({"event": "beforeAll", "data": [{}]}))
+        try:
+            json.loads(self.conn.readline())
+        except Exception:
+            pass
+
+    def tearDown(self):
+        pass
+
+    def test_output(self):
+        out = self.output.getvalue()
+        self.assertNotEqual(out.find('ValueErrorRaised'), -1)
+
+
+class TestGenericException(unittest.TestCase):
+    """
+    Tests exception handling.
+    """
+    @classmethod
+    def setUpClass(cls):
+        cls.output = io.StringIO()
+        cls.saved_stderr = sys.stderr
+        sys.stderr = cls.output
+        cls.hooks_thr = threading.Thread(target=hooks.main,
+                                         args=([os.path.abspath(__file__)],))
+        cls.hooks_thr.start()
+        time.sleep(1)
+        cls.conn = Connection()
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.output.close()
+        sys.stderr = cls.saved_stderr
+        cls.conn.close()
+        hooks.shutdown()
+        cls.hooks_thr.join()
+
+    def setUp(self):
+        self.conn.writeline(json.dumps({"event": "afterAll", "data": [{}]}))
+        try:
+            json.loads(self.conn.readline())
+        except Exception:
+            pass
+
+    def tearDown(self):
+        pass
+
+    def test_output(self):
+        out = self.output.getvalue()
+        self.assertNotEqual(out.find("ExceptionRaised"), -1)
+
+
+@hooks.before_all
+def before_all_test(transactions):
+    raise ValueError("ValueErrorRaised")
+
+
+@hooks.after_all
+def after_all_test(transactions):
+    raise Exception("ExceptionRaised")
+
+
+if __name__ == '__main__':
+    try:
+        unittest.main()
+    except Exception as e:
+        exit(-1)

test/test_multi_hooks.py

@@ -26,7 +26,6 @@ def __init__(self):
 
     def writeline(self, msg):
         msg = msg + hooks.MESSAGE_DELIMITER
-        print("%d" % (sys.version_info[0]))
         if sys.version_info[0] > 2:
             self.wfile.write(msg.encode('utf-8'))
         else: