Add OPENPHOTO_TEST_SERVER_API env var

To allow testing to be restricted to a specific maximum API version.
This allows new API tests to be skipped for old servers.

tests/README.markdown

@@ -61,3 +61,15 @@ Ensure there are:
 **TearDownClass:**
 
 Remove all photos, tags and albums
+
+### Testing old servers
+
+By default, all currently supported API versions will be tested.
+It's useful to test servers that only support older API versions.
+To restrict the testing to a specific maximum API version, use the
+``OPENPHOTO_TEST_SERVER_API`` environment variable.
+
+For example, to restrict testing to APIv1 and APIv2:
+
+    export OPENPHOTO_TEST_SERVER_API=2
+

tests/api_versions/test_v1.py

@@ -7,6 +7,5 @@ class TestAlbumsV1(test_albums.TestAlbums):
 class TestPhotosV1(test_photos.TestPhotos):
     api_version = 1
 
-# The tag API didn't work at v1 - see frontend issue #927
-# class TestTagsV1(test_tags.TestTags):
-    # api_version = 1
+class TestTagsV1(test_tags.TestTags):
+    api_version = 1

tests/api_versions/test_v2.py

@@ -1,10 +1,14 @@
-from tests import test_albums, test_photos, test_tags
+import unittest
+from tests import test_base, test_albums, test_photos, test_tags
 
+@unittest.skipIf(test_base.get_test_server_api() < 2, "Don't test future API versions")
 class TestAlbumsV2(test_albums.TestAlbums):
     api_version = 2
 
+@unittest.skipIf(test_base.get_test_server_api() < 2, "Don't test future API versions")
 class TestPhotosV2(test_photos.TestPhotos):
     api_version = 2
 
+@unittest.skipIf(test_base.get_test_server_api() < 2, "Don't test future API versions")
 class TestTagsV2(test_tags.TestTags):
     api_version = 2

tests/test_base.py

@@ -1,4 +1,5 @@
 import unittest
+import os
 import logging
 import openphoto
 
@@ -16,6 +17,9 @@ except ImportError:
            "********************************************************************\n")
     raise
 
+def get_test_server_api():
+    return int(os.getenv("OPENPHOTO_TEST_SERVER_API", openphoto.LATEST_API_VERSION))
+
 class TestBase(unittest.TestCase):
     TEST_TITLE = "Test Image - delete me!"
     TEST_TAG = "test_tag"

tests/test_framework.py

@@ -27,7 +27,7 @@ class TestFramework(test_base.TestBase):
 
     def test_specified_api_version(self):
         # For all API versions >0, we get a generic hello world message
-        for api_version in range(1, openphoto.LATEST_API_VERSION + 1):
+        for api_version in range(1, test_base.get_test_server_api() + 1):
             client = self.create_client_from_base(api_version=api_version)
             result = client.get("hello.json")
             self.assertEqual(result['message'], "Hello, world!")

tests/test_tags.py

@@ -2,6 +2,8 @@ import unittest
 import openphoto
 import test_base
 
+@unittest.skipIf(test_base.get_test_server_api() == 1,
+                 "The tag API didn't work at v1 - see frontend issue #927")
 class TestTags(test_base.TestBase):
     testcase_name = "tag API"