Fix applying referential equality inside maps and sets (#221)

src/accessDeep.ts

@@ -26,9 +26,27 @@ function validatePath(path: (string | number)[]) {
 export const getDeep = (object: object, path: (string | number)[]): object => {
   validatePath(path);
 
-  path.forEach(key => {
-    object = (object as any)[key];
-  });
+  for (let i = 0; i < path.length; i++) {
+    const key = path[i];
+    if (isSet(object)) {
+      object = getNthKey(object, +key);
+    } else if (isMap(object)) {
+      const row = +key;
+      const type = +path[++i] === 0 ? 'key' : 'value';
+
+      const keyOfRow = getNthKey(object, row);
+      switch (type) {
+        case 'key':
+          object = keyOfRow;
+          break;
+        case 'value':
+          object = object.get(keyOfRow);
+          break;
+      }
+    } else {
+      object = (object as any)[key];
+    }
+  }
 
   return object;
 };

src/index.test.ts

@@ -434,6 +434,39 @@ describe('stringify & parse', () => {
       },
     },
 
+    'works for referentially equal values in different maps and sets': {
+      input: () => {
+        const user = { id: 2 };
+
+        return {
+          workspaces: new Map([
+            [1, { users: new Set([user]) }],
+            [2, { users: new Set([user]) }],
+          ]),
+        };
+      },
+      output: {
+        workspaces: [
+          [1, { users: [{ id: 2 }] }],
+          [2, { users: [{ id: 2 }] }],
+        ],
+      },
+      outputAnnotations: {
+        values: {
+          workspaces: [
+            'map',
+            {
+              '0.1.users': ['set'],
+              '1.1.users': ['set'],
+            },
+          ],
+        },
+        referentialEqualities: {
+          'workspaces.0.1.users.0': ['workspaces.1.1.users.0'],
+        },
+      },
+    },
+
     'works for symbols': {
       skipOnNode10: true,
       input: () => {