do not create config.xml during unit test

scm-webapp/src/main/java/sonia/scm/api/v2/resources/ConfigResource.java

@@ -21,9 +21,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.api.v2.resources;
 
+import com.google.common.annotations.VisibleForTesting;
 import io.swagger.v3.oas.annotations.OpenAPIDefinition;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
@@ -45,6 +46,7 @@ import javax.ws.rs.PUT;
 import javax.ws.rs.Path;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.Response;
+import java.util.function.Consumer;
 
 /**
  * RESTful Web Service Resource to manage the configuration.
@@ -61,6 +63,8 @@ public class ConfigResource {
   private final ScmConfiguration configuration;
   private final NamespaceStrategyValidator namespaceStrategyValidator;
 
+  private Consumer<ScmConfiguration> store = (config) -> ScmConfigurationUtil.getInstance().store(config);
+
   @Inject
   public ConfigResource(ConfigDtoToScmConfigurationMapper dtoToConfigMapper,
                         ScmConfigurationToConfigDtoMapper configToDtoMapper,
@@ -71,6 +75,11 @@ public class ConfigResource {
     this.namespaceStrategyValidator = namespaceStrategyValidator;
   }
 
+  @VisibleForTesting
+  void setStore(Consumer<ScmConfiguration> store) {
+    this.store = store;
+  }
+
   /**
    * Returns the global scm config.
    */
@@ -137,7 +146,7 @@ public class ConfigResource {
     ScmConfiguration config = dtoToConfigMapper.map(configDto);
     synchronized (ScmConfiguration.class) {
       configuration.load(config);
-      ScmConfigurationUtil.getInstance().store(configuration);
+      store.accept(configuration);
     }
 
     return Response.noContent().build();