feat(json-crdt): 🎸 add inner type safety to toSchema()

Author: streamich

src/json-crdt/schema/__tests__/toSchema.spec.ts

@@ -76,3 +76,14 @@ test('can infer schema of a document nodes', () => {
   expect(cmp(obj, objSchema)).toBe(true);
   expect(cmp(con, objSchema)).toBe(false);
 });
+
+test('can infer schema of a typed model', () => {
+  const schema = s.obj({
+    id: s.con('id'),
+    val: s.val(s.str('world')),
+  });
+  const model = Model.withLogicalClock().setSchema(schema);
+  const schema2 = toSchema(model.root.node());
+  expect(schema2.obj.id).toBeInstanceOf(nodes.con);
+  expect(schema2.obj.val).toBeInstanceOf(nodes.val);
+});

src/json-crdt/schema/toSchema.ts

@@ -1,5 +1,6 @@
 import {JsonNode, ConNode, ValNode, ObjNode, VecNode, StrNode, BinNode, ArrNode} from "../nodes";
 import {NodeBuilder, s} from "../../json-crdt-patch";
+import type {JsonNodeToSchema} from "./types";
 
 /**
  * Converts any JSON CRDT node to a schema representation. The schema can be
@@ -11,27 +12,27 @@ import {NodeBuilder, s} from "../../json-crdt-patch";
  * @param node JSON CRDT node to recursively convert to schema.
  * @returns Schema representation of the JSON CRDT node.
  */
-export const toSchema = (node: JsonNode): NodeBuilder => {
-  if (node instanceof ConNode) return s.con(node.val);
-  if (node instanceof ValNode) return s.val(toSchema(node.node()));
+export const toSchema = <N extends JsonNode<any>>(node: N): JsonNodeToSchema<N> => {
+  if (node instanceof ConNode) return s.con(node.val) as any;
+  if (node instanceof ValNode) return s.val(toSchema(node.node())) as any;
   if (node instanceof ObjNode) {
     const obj: Record<string, NodeBuilder> = {};
     node.nodes((child, key) => obj[key] = toSchema(child));
-    return s.obj(obj);
+    return s.obj(obj) as any;
   }
   if (node instanceof VecNode) {
     const arr: NodeBuilder[] = [];
     node.children((child) => arr.push(toSchema(child)));
-    return s.vec(...arr);
+    return s.vec(...arr) as any;
   }
-  if (node instanceof StrNode) return s.str(node.view());
-  if (node instanceof BinNode) return s.bin(node.view());
+  if (node instanceof StrNode) return s.str(node.view()) as any;
+  if (node instanceof BinNode) return s.bin(node.view()) as any;
   if (node instanceof ArrNode) {
     const arr: NodeBuilder[] = [];
     node.children((child) => {
       if (child) arr.push(toSchema(child));
     });
-    return s.arr(arr);
+    return s.arr(arr) as any;
   }
-  return s.con(undefined);
+  return s.con(undefined) as any;
 };