Revert "temporarily disable broken test"

This reverts commit 888d89e2dd.

The code this depends on should now be available.

src/tools/config.rs

@@ -149,3 +149,23 @@ fn object_to_writer(output: &mut dyn Write, object: &Object) -> Result<(), Error
     }
     Ok(())
 }
+
+#[test]
+fn test() {
+    // let's just reuse some schema we actually have available:
+    use crate::config::node::NodeConfig;
+
+    const NODE_CONFIG: &str = "\
+        acme: account=pebble\n\
+        acmedomain0: test1.invalid.local,plugin=power\n\
+        acmedomain1: test2.invalid.local\n\
+    ";
+
+    let data: NodeConfig = from_str(NODE_CONFIG, &NodeConfig::API_SCHEMA)
+        .expect("failed to parse simple node config");
+
+    let config = to_bytes(&data, &NodeConfig::API_SCHEMA)
+        .expect("failed to serialize node config");
+
+    assert_eq!(config, NODE_CONFIG.as_bytes());
+}