[core] fix isinstace str check in core rest

sdk/core/azure-core/CHANGELOG.md

@@ -9,6 +9,7 @@
 ### Bugs Fixed
 
 - respect text encoding specified in argument (thanks to @ryohji for the contribution)  #20796
+- fix type check for `data` input to `azure.core.rest` for python 2.7 users  #21341
 
 ### Other Changes
 

sdk/core/azure-core/azure/core/rest/_helpers.py

@@ -82,13 +82,13 @@
 ########################### HELPER SECTION #################################
 
 def _verify_data_object(name, value):
-    if not isinstance(name, str):
+    if not isinstance(name, six.string_types):
         raise TypeError(
             "Invalid type for data name. Expected str, got {}: {}".format(
                 type(name), name
             )
         )
-    if value is not None and not isinstance(value, (str, bytes, int, float)):
+    if value is not None and not isinstance(value, (six.string_types, bytes, int, float)):
         raise TypeError(
             "Invalid type for data value. Expected primitive type, got {}: {}".format(
                 type(name), name

sdk/core/azure-core/tests/test_rest_http_request.py

@@ -239,6 +239,22 @@ def test_multipart_invalid_key_binary_string():
     assert "Invalid type for data name" in str(e.value)
     assert repr(b"abc") in str(e.value)
 
+def test_data_str_input():
+    data = {
+        'scope': 'fake_scope',
+        u'grant_type': 'refresh_token',
+        'refresh_token': u'REDACTED',
+        'service': 'fake_url.azurecr.io'
+    }
+    request = HttpRequest("POST", "http://localhost:3000/", data=data)
+    assert len(request.content) == 4
+    assert request.content["scope"] == "fake_scope"
+    assert request.content["grant_type"] == "refresh_token"
+    assert request.content["refresh_token"] == u"REDACTED"
+    assert request.content["service"] == "fake_url.azurecr.io"
+    assert len(request.headers) == 1
+    assert request.headers['Content-Type'] == 'application/x-www-form-urlencoded'
+
 @pytest.mark.parametrize(("value"), (object(), {"key": "value"}))
 def test_multipart_invalid_value(value):