Allow missing type in config file when looking for backend type

We missed a pick-up - and in fact the default config file that comes with this caused the bomb!

If there was a type missing, when you looked for the backend type, you'd get a bomb!

Fixes #115

Author: gordonwatts

servicex/servicex_config.py

@@ -71,9 +71,10 @@ def get_backend_info(self, backend_type: str, key: str) -> Optional[str]:
         def find_in_list(c, key) -> Optional[str]:
             if c.exists():
                 for ep in c:
-                    if ep['type'].as_str() == backend_type:
-                        if key in ep:
-                            return ep[key].as_str_expanded()
+                    if ep['type'].exists():
+                        if ep['type'].as_str() == backend_type:
+                            if key in ep:
+                                return ep[key].as_str_expanded()
             return None
 
         a = find_in_list(self._settings['api_endpoints'], key)

tests/test_servicex_config.py

@@ -50,6 +50,14 @@ def test_returned_datatype_from_endpoint():
     assert x.get_default_returned_datatype('forkit') == 'spoons'
 
 
+def test_returned_datatype_no_type_endpoint():
+    c = ConfigSettings('servicex', 'servicex')
+    c.clear()
+    c['backend_types'] = [{'type': 'forkit', 'return_data': 'spoon'}]
+    c['api_endpoints'] = [{'endpoint': 'http://localhost:5000'}]
+    x = ServiceXConfigAdaptor(c)
+    assert x.get_default_returned_datatype('forkit') == 'spoon'
+    
 def test_defalt_config_has_default_return_datatype():
     'Test default settings - default_returned_datatype'
     c = ConfigSettings('servicex', 'servicex')