MOTOR-228 Run synchro test suite with Python 3.7

.evergreen/config.yml

@@ -773,11 +773,14 @@ axes:
            TOX_ENV: "py3-pymongo-master"
            # Use 3.6 for now until 3.7 is on all Evergreen distros.
            PYTHON_BINARY: "/opt/python/3.6/bin/python3"
-      - id: "synchro"
+      - id: "synchro27"
         variables:
-           TOX_ENV: "synchro"
-           # The synchro tests are configured for py27 in tox.ini.
+           TOX_ENV: "synchro27"
            PYTHON_BINARY: "/opt/python/2.7/bin/python"
+      - id: "synchro37"
+        variables:
+          TOX_ENV: "synchro37"
+          PYTHON_BINARY: "/opt/python/3.7/bin/python3"
 
   # Test Python only up to 3.6 on Mac, until our toolchain is updated.
   - id: tox-env-osx
@@ -853,7 +856,7 @@ buildvariants:
     # TODO: synchro needs PyMongo master's updated SSL test certs,
     # which may require Motor test suite changes.
     - os: "*"
-      tox-env: ["synchro"]
+      tox-env: ["synchro27", "synchro37"]
       ssl: "ssl"
   tasks:
      - ".latest"
@@ -883,7 +886,7 @@ buildvariants:
 
 - matrix_name: "enterprise-auth"
   display_name: "Enterprise Auth"
-  matrix_spec: {"tox-env": ["synchro"], ssl: "ssl"}
+  matrix_spec: {"tox-env": ["synchro27"], ssl: "ssl"}
   run_on:
      - ubuntu1604-test
   tasks:

.evergreen/run-tox.sh

@@ -24,7 +24,7 @@ if [ "$SSL" != "nossl" ]; then
     export CA_PEM="$DRIVERS_TOOLS/.evergreen/x509gen/ca.pem"
 fi
 
-if [ "$TOX_ENV" = "synchro" ]; then
+if [ "$TOX_ENV" = "synchro27" -o "$TOX_ENV" = "synchro37" ]; then
     SETUP_ARGS="-- --check-exclude-patterns"
 fi
 

doc/developer-guide.rst

@@ -108,5 +108,6 @@ synchronous and Motor is async; how can Motor pass PyMongo's tests?
 Synchro is a hacky little module that re-synchronizes all Motor methods using
 the Tornado IOLoop's ``run_sync`` method. ``synchrotest.py`` overrides the Python
 interpreter's import machinery to allow Synchro to masquerade as PyMongo, and
-runs PyMongo's test suite against it. Use ``tox -e synchro`` to check out
-PyMongo's test suite and run it with Synchro.
+runs PyMongo's test suite against it. Use ``tox -e synchro27`` or
+``tox -e synchro37`` to check out PyMongo's test suite and run it with
+Synchro.

synchro/__init__.py

@@ -674,19 +674,3 @@ class GridOut(Synchro):
 
         super(GridOut, self).__setattr__(key, value)
 
-
-class TimeModule(object):
-    """Fake time module so time.sleep() lets other tasks run on the IOLoop.
-
-    See e.g. test_schedule_refresh() in test_replica_set_client.py.
-    """
-    def __getattr__(self, item):
-        def sleep(seconds):
-            loop = IOLoop.current()
-            loop.add_timeout(time.time() + seconds, loop.stop)
-            loop.start()
-
-        if item == 'sleep':
-            return sleep
-        else:
-            return getattr(time, item)

synchro/synchrotest.py

@@ -306,10 +306,6 @@ if __name__ == '__main__':
     # real PyMongo.
     sys.meta_path[0:0] = [SynchroModuleFinder()]
 
-    # Ensure time.sleep() acts as PyMongo's tests expect: background tasks
-    # can run to completion while foreground pauses.
-    sys.modules['time'] = synchro.TimeModule()
-
     if '--check-exclude-patterns' in sys.argv:
         check_exclude_patterns = True
         sys.argv.remove('--check-exclude-patterns')

tox.ini

@@ -30,7 +30,8 @@ envlist =
     py3-pymongo-master,
 
     # Apply PyMongo's test suite to Motor via Synchro.
-    synchro
+    synchro27,
+    synchro37
 
 [testenv]
 passenv =
@@ -42,11 +43,11 @@ passenv =
     ASYNC_TEST_TIMEOUT
 
 basepython =
-    py27,synchro: {env:PYTHON_BINARY:python2.7}
+    py27,synchro27: {env:PYTHON_BINARY:python2.7}
     py34: {env:PYTHON_BINARY:python3.4}
     py35: {env:PYTHON_BINARY:python3.5}
     py36: {env:PYTHON_BINARY:python3.6}
-    py37: {env:PYTHON_BINARY:python3.7}
+    py37,synchro37: {env:PYTHON_BINARY:python3.7}
     pypy: {env:PYTHON_BINARY:pypy}
     pypy3: {env:PYTHON_BINARY:pypy3}
 
@@ -70,9 +71,12 @@ deps =
     py3-pymongo-master: git+https://github.com/mongodb/mongo-python-driver.git
     py3-pymongo-master: tornado>=5,<6
 
-    synchro: tornado>=5,<6
-    synchro: nose
-    synchro: futures
+    synchro27: tornado>=5,<6
+    synchro27: nose
+    synchro27: futures
+
+    synchro37: tornado>=6,<7
+    synchro37: nose
 
 commands =
     python --version
@@ -89,7 +93,7 @@ changedir = doc
 commands =
     sphinx-build -q -E -b doctest . {envtmpdir}/doctest {posargs}
 
-[testenv:synchro]
+[testenv:synchro27]
 whitelist_externals =
     git
 setenv =
@@ -97,3 +101,12 @@ setenv =
 commands =
     git clone --depth 1 https://github.com/mongodb/mongo-python-driver.git {envtmpdir}/mongo-python-driver
     python -m synchro.synchrotest -v -w {envtmpdir}/mongo-python-driver {posargs}
+
+[testenv:synchro37]
+whitelist_externals =
+    git
+setenv =
+    PYTHONPATH = {envtmpdir}/mongo-python-driver
+commands =
+    git clone --depth 1 https://github.com/mongodb/mongo-python-driver.git {envtmpdir}/mongo-python-driver
+    python3 -m synchro.synchrotest -v -w {envtmpdir}/mongo-python-driver {posargs}