log syntax errors

src/webfused/config/factory.c

@@ -84,8 +84,16 @@ wfd_config_load_file(
     if (CONFIG_TRUE == rc)
     {
         result = wfd_config_load(&config);
-        config_destroy(&config);
     }
+    else
+    {
+        WFD_ERROR("failed to load config: %s: %d: %s", 
+            config_error_file(&config),
+            config_error_line(&config),
+            config_error_text(&config));
+    }
+    config_destroy(&config);
+    
 
     return result;
 }
@@ -102,8 +110,15 @@ wfd_config_load_string(
     if (CONFIG_TRUE == rc)
     {
         result = wfd_config_load(&config);
-        config_destroy(&config);
     }
+    else
+    {
+        WFD_ERROR("failed to load config: %d: %s", 
+            config_error_line(&config),
+            config_error_text(&config));
+    }
+    config_destroy(&config);
+    
 
     return result;
 }

test/test_config.cc

@@ -31,6 +31,18 @@ TEST(config, minimal_config)
     wfd_config_dispose(config);
 }
 
+TEST(config, invalid_config)
+{
+    MockLogger logger;
+    EXPECT_CALL(logger, log(WFD_LOGLEVEL_ERROR, _, _)).Times(1);
+    EXPECT_CALL(logger, onclose()).Times(1);
+
+    char const syntax_error[] = "version.major = 1\n";
+
+    struct wfd_config * config = wfd_config_load_string(syntax_error);
+    ASSERT_EQ(nullptr, config);    
+}
+
 TEST(config, invalid_major_version_too_low)
 {
     MockLogger logger;