feat(json-crdt): 🎸 improve schema comparison script

Author: streamich

src/json-crdt/equal/__tests__/index.spec.ts

@@ -2,18 +2,33 @@ import {Model} from '../../model';
 import {equalSchema} from '..';
 import {s} from '../../../json-crdt-patch';
 
-describe('equalSchema()', () => {
+describe('equalSchema(), schema only', () => {
+  const assertSchemasEqual = (a: unknown, b: unknown): void => {
+    const model1 = Model.create(a);
+    const model2 = Model.create(b);
+    const result = equalSchema(model1.root, model2.root, false);
+    expect(result).toBe(true);
+  };
+
+  test('returns true for identical nodes', () => {
+    assertSchemasEqual(new Uint8Array([1, 2, 3]), new Uint8Array([1, 2, 4]));
+    assertSchemasEqual({foo: 'bar', num: 123}, {foo: 'baz', num: 456});
+    expect(() => assertSchemasEqual({foo: 'bar', num: 123}, {foo: 'baz', num: 456, x: 'y'})).toThrow();
+  });
+});
+
+describe('equalSchema(), with content comparison', () => {
   const assertSchemasEqual = (a: unknown): void => {
     const model1 = Model.create(a);
     const model2 = Model.create(a);
-    const result = equalSchema(model1.root, model2.root);
+    const result = equalSchema(model1.root, model2.root, true);
     expect(result).toBe(true);
   };
 
   const assertSchemasDifferent = (a: unknown, b: unknown): void => {
     const model1 = Model.create(a);
     const model2 = Model.create(b);
-    const result = equalSchema(model1.root, model2.root);
+    const result = equalSchema(model1.root, model2.root, true);
     expect(result).toBe(false);
   };
 

src/json-crdt/equal/index.ts

@@ -10,11 +10,11 @@ import {ArrNode, BinNode, ConNode, JsonNode, ObjNode, StrNode, ValNode, VecNode}
  * @param b The second JSON CRDT node.
  * @returns True if the schemas and values are equal, false otherwise.
  */
-export const equalSchema = <A extends JsonNode<any>>(a: A, b: unknown): b is A => {
+export const equalSchema = <A extends JsonNode<any>>(a: A, b: unknown, compareContent: boolean): b is A => {
   if (a === b) return true;
-  if (a instanceof ConNode) return b instanceof ConNode && deepEqual(a.val, b.val);
-  else if (a instanceof ValNode) return b instanceof ValNode && equalSchema(a.node(), b.node());
-  else if (a instanceof StrNode) return b instanceof StrNode && a.length() === b.length() && a.view() === b.view();
+  if (a instanceof ConNode) return b instanceof ConNode && (!compareContent || deepEqual(a.val, b.val));
+  else if (a instanceof ValNode) return b instanceof ValNode && equalSchema(a.node(), b.node(), compareContent);
+  else if (a instanceof StrNode) return b instanceof StrNode && (!compareContent || (a.length() === b.length() && a.view() === b.view()));
   else if (a instanceof ObjNode) {
     if (!(b instanceof ObjNode)) return false;
     const keys1 = a.keys;
@@ -24,22 +24,22 @@ export const equalSchema = <A extends JsonNode<any>>(a: A, b: unknown): b is A =
     if (length1 !== length2) return false;
     for (const key of keys1.keys()) {
       if (!keys2.has(key)) return false;
-      if (!equalSchema(a.get(key), b.get(key))) return false;
+      if (!equalSchema(a.get(key), b.get(key), compareContent)) return false;
     }
     return true;
   } else if (a instanceof ArrNode) {
     if (!(b instanceof ArrNode)) return false;
     const length = a.length();
     if (length !== b.length()) return false;
-    for (let i = 0; i < length; i++) if (!equalSchema(a.getNode(i)!, b.getNode(i))) return false;
+    for (let i = 0; i < length; i++) if (!equalSchema(a.getNode(i)!, b.getNode(i), compareContent)) return false;
     return true;
   } else if (a instanceof VecNode) {
     if (!(b instanceof VecNode)) return false;
     const length = a.length();
     if (length !== b.length()) return false;
-    for (let i = 0; i < length; i++) if (!equalSchema(a.get(i), b.get(i))) return false;
+    for (let i = 0; i < length; i++) if (!equalSchema(a.get(i), b.get(i), compareContent)) return false;
     return true;
   } else if (a instanceof BinNode)
-    return b instanceof BinNode && a.length() === b.length() && deepEqual(a.view(), b.view());
+    return b instanceof BinNode && (!compareContent || (a.length() === b.length() && deepEqual(a.view(), b.view())));
   return false;
 };