add version field to diagram

Signed-off-by: Teo Koon Peng <[email protected]>

Author: koonpeng

diagram.schema.json

@@ -4,7 +4,8 @@
   "type": "object",
   "required": [
     "ops",
-    "start"
+    "start",
+    "version"
   ],
   "properties": {
     "ops": {
@@ -20,6 +21,13 @@
           "$ref": "#/definitions/NextOperation"
         }
       ]
+    },
+    "version": {
+      "description": "Version of the diagram, should always be `1`.",
+      "type": "integer",
+      "format": "uint32",
+      "maximum": 1.0,
+      "minimum": 1.0
     }
   },
   "definitions": {

src/diagram.rs

@@ -271,6 +271,10 @@ type DiagramScope<Streams = ()> = Scope<DiagramStart, DiagramTerminate, Streams>
 #[derive(JsonSchema, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 pub struct Diagram {
+    /// Version of the diagram, should always be `1`.
+    #[schemars(range(min = 1, max = 1))]
+    version: u32,
+
     /// Signifies the start of a workflow.
     start: NextOperation,