fix(overlays): fix condition in is-equal-config util and add null guard

.changeset/sour-rules-rush.md

@@ -0,0 +1,5 @@
+---
+'@lion/overlays': patch
+---
+
+fix condition in is-equal-config util and add null guard

packages/overlays/src/utils/is-equal-config.js

@@ -11,7 +11,7 @@
  * @returns {boolean} Whether the configs are equivalent
  */
 export function isEqualConfig(a, b) {
-  if (typeof a !== 'object' || typeof a !== 'object') {
+  if (typeof a !== 'object' || typeof b !== 'object' || a === null || b === null) {
     return a === b;
   }
   const aProps = Object.keys(a);

packages/overlays/test/utils-tests/is-equal-config.test.js

@@ -23,6 +23,18 @@ describe('isEqualConfig()', () => {
     expect(isEqualConfig(config, config)).eql(true);
   });
 
+  it('compares null props', () => {
+    const config = TestConfig();
+    const nullPropConfig = {
+      ...config,
+      elementToFocusAfterHide: {
+        nullProp: null,
+      },
+    };
+    // @ts-ignore
+    expect(isEqualConfig(nullPropConfig, nullPropConfig)).eql(true);
+  });
+
   it('compares shallow props', () => {
     const config = TestConfig();
     expect(isEqualConfig(config, { ...config })).eql(true);