random generator for mongo documents, test that to_dict o from_dict is identity. fix get_c_string to check for 0 bytes

bson.py

@@ -35,7 +35,15 @@ def _get_c_string(data):
     return (unicode(data[:end], "utf-8"), data[end + 1:])
 
 def _make_c_string(string):
-    return string.encode("utf-8") + "\x00"
+    string = string.encode("utf-8")
+    try:
+        string.index("\x00")
+        raise InvalidDocument("cannot encode string %r: contains '\\x00'" % string)
+    except InvalidDocument:
+        raise
+    except ValueError:
+        pass
+    return string + "\x00"
 
 def _validate_number(data):
     assert len(data) >= 8
@@ -47,9 +55,8 @@ def _validate_string(data):
     assert data[length - 1] == "\x00"
     return data[length:]
 
-_valid_object_name = re.compile("^.*$")
 def _validate_object(data):
-    return _validate_document(data, _valid_object_name)
+    return _validate_document(data, None)
 
 _valid_array_name = re.compile("^\d+$")
 def _validate_array(data):
@@ -120,19 +127,20 @@ def _validate_element_data(type, data):
     try:
         return _element_validator[type](data)
     except KeyError:
-        raise InvalidBSON()
+        raise InvalidBSON("unrecognized type: %s" % type)
 
 def _validate_element(data, valid_name):
     element_type = data[0]
     (element_name, data) = _get_c_string(data[1:])
-    assert valid_name.match(element_name)
+    if valid_name:
+        assert valid_name.match(element_name), "%r doesn't match %s" % (element_name, valid_name.pattern)
     return _validate_element_data(element_type, data)
 
 def _validate_elements(data, valid_name):
     while data:
         data = _validate_element(data, valid_name)
 
-def _validate_document(data, valid_name=_valid_object_name):
+def _validate_document(data, valid_name=None):
     try:
         obj_size = struct.unpack("<i", data[:4])[0]
     except struct.error:
@@ -364,5 +372,10 @@ class TestBSON(unittest.TestCase):
         helper({"an array": [1, True, 3.8, u"world"]})
         helper({"an object": {"test": u"something"}})
 
+        def from_then_to_dict(dict):
+            return dict == (BSON.from_dict(dict)).to_dict()
+
+        qcheck.check_unittest(self, from_then_to_dict, qcheck.gen_mongo_dict(3))
+
 if __name__ == "__main__":
     unittest.main()

test/qcheck.py

@@ -1,4 +1,6 @@
 import random
+import sys
+import traceback
 
 gen_target = 100
 examples = 5
@@ -6,14 +8,59 @@ examples = 5
 def gen_range(start, stop):
     return lambda: random.randint(start, stop)
 
-def char():
-    return chr(random.randint(0, 255))
+def gen_int():
+    return lambda: random.randint(-sys.maxint-1, sys.maxint)
+
+def gen_float():
+    return lambda: (random.random() - 0.5) * sys.maxint
+
+def gen_boolean():
+    return lambda: random.choice([True, False])
+
+def gen_printable_char():
+    return lambda: chr(random.randint(32, 126))
+
+def gen_printable_string(gen_length):
+    return lambda: "".join(gen_list(gen_printable_char(), gen_length)())
+
+def gen_char():
+    return lambda: chr(random.randint(0, 255))
 
 def gen_string(gen_length):
-    return lambda: "".join(gen_list(char, gen_length))
+    return lambda: "".join(gen_list(gen_char(), gen_length)())
 
-def gen_list(generator, length):
-    return [generator() for _ in range(length())]
+def gen_unichar():
+    return lambda: unichr(random.randint(1, 0xFFFF))
+
+def gen_unicode(gen_length):
+    return lambda: u"".join(gen_list(gen_unichar(), gen_length)())
+
+def gen_list(generator, gen_length):
+    return lambda: [generator() for _ in range(gen_length())]
+
+def gen_dict(gen_key, gen_value, gen_length):
+    def a_dict(gen_key, gen_value, length):
+        result = {}
+        for _ in range(length):
+            result[gen_key()] = gen_value()
+        return result
+    return lambda: a_dict(gen_key, gen_value, gen_length())
+
+def gen_mongo_value(depth):
+    choices = [gen_unicode(gen_range(0, 50)),
+               gen_int(),
+               gen_float(),
+               gen_boolean()]
+    if depth > 0:
+        choices.append(gen_mongo_list(depth))
+        choices.append(gen_mongo_dict(depth))
+    return lambda: random.choice(choices)()
+
+def gen_mongo_list(depth):
+    return gen_list(gen_mongo_value(depth - 1), gen_range(0, 10))
+
+def gen_mongo_dict(depth):
+    return gen_dict(gen_unicode(gen_range(0, 20)), gen_mongo_value(depth - 1), gen_range(0, 10))
 
 
 def isnt(predicate):
@@ -22,10 +69,13 @@ def isnt(predicate):
 
 def check(predicate, generator):
     counter_examples = []
-    for i in range(gen_target):
+    for _ in range(gen_target):
         case = generator()
-        if not predicate(case):
-            counter_examples.append(repr(case))
+        try:
+            if not predicate(case):
+                counter_examples.append(repr(case))
+        except:
+            counter_examples.append("%r : %s" % (case, traceback.format_exc()))
     return counter_examples
 
 def check_unittest(test, predicate, generator):