Fixed #1258: cannot replace map contents using another map

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 3.3.3
+
+* Fixed regression bug where observable map contents could not be replaced using another observable map [#1258](https://github.com/mobxjs/mobx/issues/1258)
+
 # 3.3.2
 
 * Fix bug where custom comparers could be invoked with `undefined` values. Fixes [#1208](https://github.com/mobxjs/mobx/issues/1208)

src/utils/utils.ts

@@ -146,7 +146,7 @@ export function getEnumerableKeys(obj) {
 export function deepEqual(a, b) {
     if (a === null && b === null) return true
     if (a === undefined && b === undefined) return true
-    if (areBothNaN(a, b)) return true    
+    if (areBothNaN(a, b)) return true
     if (typeof a !== "object") return a === b
     const aIsArray = isArrayLike(a)
     const aIsMap = isMapLike(a)
@@ -217,7 +217,7 @@ export function getMapLikeKeys<V>(map: ObservableMap<V> | IKeyValueMap<V> | any)
 	let keys;
 	if (isPlainObject(map)) keys = Object.keys(map)
 	else if (Array.isArray(map)) keys = map.map(([key]) => key)
-	else if (isES6Map(map)) keys = (Array as any).from(map.keys())
+	else if (isMapLike(map)) keys = (Array as any).from(map.keys())
 	else fail("Cannot get keys from " + map)
 	return keys;
 }

test/map.js

@@ -678,3 +678,10 @@ test("issue 1243, .replace should not trigger change on unchanged values", t =>
     d()
     t.end()
 })
+
+test("#1258 cannot replace maps anymore", t => {
+	const items = mobx.observable.map()
+	items.replace(mobx.observable.map())
+
+	t.end()
+})