Roundtrip schemas in syncback (#1173)

src/snapshot/metadata.rs

@@ -66,6 +66,10 @@ pub struct InstanceMetadata {
     /// The Middleware that was used to create this Instance. Should generally
     /// not be `None` except if the snapshotting process is not completed.
     pub middleware: Option<Middleware>,
+
+    /// A schema provided via a JSON file, if one exists. Will be `None` for
+    /// all non-JSON middleware.
+    pub schema: Option<String>,
 }
 
 impl InstanceMetadata {
@@ -77,6 +81,7 @@ impl InstanceMetadata {
             context: InstanceContext::default(),
             specified_id: None,
             middleware: None,
+            schema: None,
         }
     }
 
@@ -121,6 +126,10 @@ impl InstanceMetadata {
             ..self
         }
     }
+
+    pub fn schema(self, schema: Option<String>) -> Self {
+        Self { schema, ..self }
+    }
 }
 
 impl Default for InstanceMetadata {

src/snapshot/tests/snapshots/librojo__snapshot__tests__apply__add_property.snap

@@ -15,5 +15,5 @@ metadata:
     emit_legacy_scripts: true
   specified_id: ~
   middleware: ~
+  schema: ~
 children: []
-

src/snapshot/tests/snapshots/librojo__snapshot__tests__apply__remove_property_after_patch.snap

@@ -13,5 +13,5 @@ metadata:
     emit_legacy_scripts: true
   specified_id: ~
   middleware: ~
+  schema: ~
 children: []
-

src/snapshot/tests/snapshots/librojo__snapshot__tests__apply__remove_property_initial.snap

@@ -15,5 +15,5 @@ metadata:
     emit_legacy_scripts: true
   specified_id: ~
   middleware: ~
+  schema: ~
 children: []
-

src/snapshot/tests/snapshots/librojo__snapshot__tests__apply__set_name_and_class_name.snap

@@ -13,5 +13,5 @@ metadata:
     emit_legacy_scripts: true
   specified_id: ~
   middleware: ~
+  schema: ~
 children: []
-

src/snapshot/tests/snapshots/librojo__snapshot__tests__compute__add_child.snap

@@ -14,9 +14,9 @@ added_instances:
           emit_legacy_scripts: true
         specified_id: ~
         middleware: ~
+        schema: ~
       name: New
       class_name: Folder
       properties: {}
       children: []
 updated_instances: []
-