Updated test_env_yml.py file

tests/test_env_yml.py

@@ -6,18 +6,20 @@ import sys
 import pytest
 from repo2docker import buildpacks
 
-#@pytest.mark.xfail(reason="Not yet implemented")
+
 def test_empty_env_yml(tmpdir):
     tmpdir.chdir()
     p = tmpdir.join("environment.yml")
+    p.write("")
     bp = buildpacks.CondaBuildPack()
-    with pytest.raises(Exception):
-        py_ver = bp.python_version()
+    py_ver = bp.python_version
+    # If the environment.yml is empty python_version will get an empty string
+    assert py_ver == ''
 
 def test_no_dict_env_yml(tmpdir):
     tmpdir.chdir()
     q = tmpdir.join("environment.yml")
     q.write("list/n ,string")
     bq = buildpacks.CondaBuildPack()
-    with pytest.raises(Exception):
-        py_ver = bq.python_version()
+    with pytest.raises(TypeError):
+        py_ver = bq.python_version