Implement main-thread Camino sessions and synchronous CRDT editing

src/query/schema.ts

@@ -126,8 +126,29 @@ export function querySchema(
       );
     return views[0]!.interfaceRevisionId;
   };
+  const variants = new Map<string, GraphQLScalarType>();
   const scalar = (type: ValueType): GraphQLOutputType & GraphQLInputType => {
     if (type.kind === "optional") return scalar(type.value);
+    if (type.kind === "variant") {
+      const name = `QxVariant_${createHash("sha256").update(JSON.stringify(type)).digest("hex").slice(0, 16)}`;
+      let result = variants.get(name);
+      if (!result) {
+        result = new GraphQLScalarType({
+          name,
+          description: "Whole checked Camino variant value. Branch selection and predicates are not supported.",
+          serialize: (value) => value,
+          parseValue() {
+            throw new QueryCompileError("QUERY_TYPE", "Variant query inputs are not supported");
+          },
+          parseLiteral() {
+            throw new QueryCompileError("QUERY_TYPE", "Variant query inputs are not supported");
+          },
+        });
+        variants.set(name, result);
+        scalarTypes.set(name, type);
+      }
+      return result;
+    }
     if (type.kind !== "scalar")
       throw new QueryCompileError("QUERY_TYPE", "Only scalar/optional scalar query fields are supported");
     return queryScalars[type.name];