fix(apply): fix apply with patches non-string keys (#151)

Author: unadlib

src/apply.ts

@@ -57,19 +57,34 @@ export function apply<
       for (let index = 0; index < path.length - 1; index += 1) {
         const parentType = getType(base);
         let key = path[index];
-        if (typeof key !== 'string' && typeof key !== 'number') {
-          key = String(key);
-        }
+        const keyForCheck =
+          typeof key === 'symbol' ? undefined : String(key as any);
         if (
           ((parentType === DraftType.Object ||
             parentType === DraftType.Array) &&
-            (key === '__proto__' || key === 'constructor')) ||
-          (typeof base === 'function' && key === 'prototype')
+            keyForCheck !== undefined &&
+            (keyForCheck === '__proto__' || keyForCheck === 'constructor')) ||
+          (typeof base === 'function' &&
+            keyForCheck !== undefined &&
+            keyForCheck === 'prototype')
         ) {
           throw new Error(
             `Patching reserved attributes like __proto__ and constructor is not allowed.`
           );
         }
+        if (
+          (parentType === DraftType.Object ||
+            parentType === DraftType.Array ||
+            typeof base === 'function') &&
+          typeof key !== 'string' &&
+          typeof key !== 'number' &&
+          typeof key !== 'symbol'
+        ) {
+          // keyForCheck cannot be undefined here, because:
+          // - If key is a symbol, this conditional block will not be entered
+          // - All other types will be converted to String(key)
+          key = keyForCheck!;
+        }
         // use `index` in Set draft
         base = get(parentType === DraftType.Set ? Array.from(base) : base, key);
         if (typeof base !== 'object') {

test/immer-non-support.test.ts

@@ -735,3 +735,69 @@ test('Unexpected undefined not assigned', () => {
     expect(Object.prototype.hasOwnProperty.call(foo, 'name')).toBe(true);
   }
 });
+
+test('apply - map with object key', () => {
+  {
+    enablePatches();
+    enableMapSet();
+    const key = { id: 1 };
+    const base = {
+      map: new Map([[key, { value: 1 }]]),
+    };
+    const [next, patches, inverse] = produceWithPatches(base, (draft) => {
+      draft.map.get(key)!.value = 2;
+    });
+    expect(() => applyPatches(base, patches)).toThrow();
+    expect(() => applyPatches(next, inverse)).toThrow();
+  }
+  {
+    const key = { id: 1 };
+    const base = {
+      map: new Map([[key, { value: 1 }]]),
+    };
+    const [next, patches, inverse] = create(
+      base,
+      (draft) => {
+        draft.map.get(key)!.value = 2;
+      },
+      { enablePatches: true }
+    );
+    expect(apply(base, patches)).toEqual(next);
+    expect(apply(next, inverse)).toEqual(base);
+  }
+});
+
+test('apply - symbol key on object', () => {
+  {
+    enablePatches();
+    const sym = Symbol('key');
+    const base = {
+      obj: {
+        [sym]: { value: 1 },
+      },
+    };
+    const [next, patches, inverse] = produceWithPatches(base, (draft) => {
+      draft.obj[sym].value = 2;
+    });
+    expect(() => applyPatches(base, patches)).toThrow();
+    expect(() => applyPatches(next, inverse)).toThrow();
+  }
+  {
+    const sym = Symbol('key');
+    const base = {
+      obj: {
+        [sym]: { value: 1 },
+      },
+    };
+    const [next, patches, inverse] = create(
+      base,
+      (draft) => {
+        draft.obj[sym].value = 2;
+      },
+      { enablePatches: true }
+    );
+    expect(apply(base, patches)).toEqual(next);
+    expect(apply(next, inverse)).toEqual(base);
+  }
+});
+

test/index.test.ts

@@ -4086,6 +4086,58 @@ test('#59 - Failure to apply inverse patchset(Map)', () => {
   expect(reverted2).toEqual(newState);
 });
 
+test('apply - map with object key', () => {
+  const key = { id: 1 };
+  const base = {
+    map: new Map([[key, { value: 1 }]]),
+  };
+  const [next, patches, inverse] = create(
+    base,
+    (draft) => {
+      draft.map.get(key)!.value = 2;
+    },
+    { enablePatches: true }
+  );
+  expect(apply(base, patches)).toEqual(next);
+  expect(apply(next, inverse)).toEqual(base);
+});
+
+test('apply - symbol key on object', () => {
+  const sym = Symbol('key');
+  const base = {
+    obj: {
+      [sym]: { value: 1 },
+    },
+  };
+  const [next, patches, inverse] = create(
+    base,
+    (draft) => {
+      draft.obj[sym].value = 2;
+    },
+    { enablePatches: true }
+  );
+  expect(apply(base, patches)).toEqual(next);
+  expect(apply(next, inverse)).toEqual(base);
+});
+
+test('apply - coerces non-primitive intermediate key for object', () => {
+  const objectKey: any = { toString: () => 'customKey' };
+  const base = {
+    foo: {
+      customKey: { value: 1 },
+    },
+  };
+  const patches: any = [
+    { op: 'replace', path: ['foo', objectKey, 'value'], value: 2 },
+  ];
+  const applied = apply(base, patches);
+  expect(applied).toEqual({
+    foo: {
+      customKey: { value: 2 },
+    },
+  });
+});
+
 test('#61 - type issue: current of Draft<T> type should return T type', () => {
   function test<T extends { x: { y: ReadonlySet<string> } }>(base: T): T {
     const [draft, f] = create(base);