PYTHON-1316 Remove Database.eval and database.SystemJS

Author: ShaneHarvey

doc/changelog.rst

@@ -15,6 +15,7 @@ Breaking Changes in 4.0
 .......................
 
 - Removed support for Python 2.7, 3.4, and 3.5. Python 3.6+ is now required.
+- Removed :meth:`~pymongo.database.Database.eval` and :class:`~pymongo.database.SystemJS`.
 - Removed :mod:`~pymongo.thread_util`.
 
 Notable improvements

doc/migrate-to-pymongo4.rst

@@ -7,7 +7,8 @@ PyMongo 4 Migration Guide
 
   from pymongo import MongoClient, ReadPreference
   client = MongoClient()
-  collection = client.my_database.my_collection
+  database = client.my_database
+  collection = database.my_collection
 
 PyMongo 4.0 brings a number of improvements as well as some backward breaking
 changes. This guide provides a roadmap for migrating an existing application
@@ -49,5 +50,26 @@ Warnings can also be changed to errors::
 .. note:: Not all deprecated features raise :exc:`DeprecationWarning` when
   used. See `Removed features with no migration path`_.
 
+Database
+--------
+
+The "eval" method and SystemJS class are removed
+................................................
+
+Removed :meth:`~pymongo.database.Database.eval` and
+:class:`~pymongo.database.SystemJS`. The eval command was deprecated in
+MongoDB 3.0 and removed in MongoDB 4.2.
+
+Code like this::
+
+  >>> result = database.eval('function (x) {return x;}', 3)
+
+can be changed to this with MongoDB <= 4.0:
+
+.. doctest::
+
+  >>> from bson.code import Code
+  >>> result = database.command('eval', Code('function (x) {return x;}'), args=[3]).get('retval')
+
 Removed features with no migration path
 ---------------------------------------

pymongo/database.py

@@ -145,14 +145,6 @@ def method_overwritten(instance, method):
             if method_overwritten(manipulator, "transform_outgoing"):
                 self.__outgoing_manipulators.insert(0, manipulator)
 
-    @property
-    def system_js(self):
-        """**DEPRECATED**: :class:`SystemJS` helper for this :class:`Database`.
-
-        See the documentation for :class:`SystemJS` for more details.
-        """
-        return SystemJS(self)
-
     @property
     def client(self):
         """The client instance for this :class:`Database`."""
@@ -1547,77 +1539,3 @@ def dereference(self, dbref, session=None, **kwargs):
                                                                self.__name))
         return self[dbref.collection].find_one(
             {"_id": dbref.id}, session=session, **kwargs)
-
-    def eval(self, code, *args):
-        """**DEPRECATED**: Evaluate a JavaScript expression in MongoDB.
-
-        :Parameters:
-          - `code`: string representation of JavaScript code to be
-            evaluated
-          - `args` (optional): additional positional arguments are
-            passed to the `code` being evaluated
-
-        .. warning:: the eval command is deprecated in MongoDB 3.0 and
-          will be removed in a future server version.
-        """
-        warnings.warn("Database.eval() is deprecated",
-                      DeprecationWarning, stacklevel=2)
-
-        if not isinstance(code, Code):
-            code = Code(code)
-
-        result = self.command("$eval", code, args=args)
-        return result.get("retval", None)
-
-    def __call__(self, *args, **kwargs):
-        """This is only here so that some API misusages are easier to debug.
-        """
-        raise TypeError("'Database' object is not callable. If you meant to "
-                        "call the '%s' method on a '%s' object it is "
-                        "failing because no such method exists." % (
-                            self.__name, self.__client.__class__.__name__))
-
-
-class SystemJS(object):
-    """**DEPRECATED**: Helper class for dealing with stored JavaScript.
-    """
-
-    def __init__(self, database):
-        """**DEPRECATED**: Get a system js helper for the database `database`.
-
-        SystemJS will be removed in PyMongo 4.0.
-        """
-        warnings.warn("SystemJS is deprecated",
-                      DeprecationWarning, stacklevel=2)
-
-        if not database.write_concern.acknowledged:
-            database = database.client.get_database(
-                database.name, write_concern=DEFAULT_WRITE_CONCERN)
-        # can't just assign it since we've overridden __setattr__
-        object.__setattr__(self, "_db", database)
-
-    def __setattr__(self, name, code):
-        self._db.system.js.replace_one(
-            {"_id": name}, {"_id": name, "value": Code(code)}, True)
-
-    def __setitem__(self, name, code):
-        self.__setattr__(name, code)
-
-    def __delattr__(self, name):
-        self._db.system.js.delete_one({"_id": name})
-
-    def __delitem__(self, name):
-        self.__delattr__(name)
-
-    def __getattr__(self, name):
-        return lambda *args: self._db.eval(Code("function() { "
-                                                "return this[name].apply("
-                                                "this, arguments); }",
-                                                scope={'name': name}), *args)
-
-    def __getitem__(self, name):
-        return self.__getattr__(name)
-
-    def list(self):
-        """Get a list of the names of the functions stored in this database."""
-        return [x["_id"] for x in self._db.system.js.find(projection=["_id"])]

test/test_database.py

@@ -806,35 +806,6 @@ def test_deref_kwargs(self):
                          db.dereference(DBRef("test", 4),
                                         projection={"_id": False}))
 
-    @client_context.require_no_auth
-    @client_context.require_version_max(4, 1, 0)
-    def test_eval(self):
-        db = self.client.pymongo_test
-        db.test.drop()
-
-        with ignore_deprecations():
-            self.assertRaises(TypeError, db.eval, None)
-            self.assertRaises(TypeError, db.eval, 5)
-            self.assertRaises(TypeError, db.eval, [])
-
-            self.assertEqual(3, db.eval("function (x) {return x;}", 3))
-            self.assertEqual(3, db.eval(u"function (x) {return x;}", 3))
-
-            self.assertEqual(None,
-                             db.eval("function (x) {db.test.save({y:x});}", 5))
-            self.assertEqual(db.test.find_one()["y"], 5)
-
-            self.assertEqual(5, db.eval("function (x, y) {return x + y;}", 2, 3))
-            self.assertEqual(5, db.eval("function () {return 5;}"))
-            self.assertEqual(5, db.eval("2 + 3;"))
-
-            self.assertEqual(5, db.eval(Code("2 + 3;")))
-            self.assertRaises(OperationFailure, db.eval, Code("return i;"))
-            self.assertEqual(2, db.eval(Code("return i;", {"i": 2})))
-            self.assertEqual(5, db.eval(Code("i + 3;", {"i": 2})))
-
-            self.assertRaises(OperationFailure, db.eval, "5 ++ 5;")
-
     # TODO some of these tests belong in the collection level testing.
     def test_insert_find_one(self):
         db = self.client.pymongo_test