fix(objectContaining): Fixed a bug where ObjectContaining matched with non-object values. (#15463)

mohammednumaan · web-flow · commit 9753fdcf2a71 · 2025-05-22T17:27:01.000+09:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -99,6 +99,10 @@
 - `[jest-util]` Always load `mjs` files with `import` ([#15447](https://github.com/jestjs/jest/pull/15447))
 - `[jest-worker]` Properly handle a circular reference error when worker tries to send an assertion fails where either the expected or actual value is circular ([#15191](https://github.com/jestjs/jest/pull/15191))
 - `[jest-worker]` Properly handle a BigInt when worker tries to send an assertion fails where either the expected or actual value is BigInt ([#15191](https://github.com/jestjs/jest/pull/15191))
+- `[expect]` Resolve issue where `ObjectContaining` matched non-object values. ([#15463])(https://github.com/jestjs/jest/pull/15463).
+  - Adds a `conditional/check` to ensure the argument passed to `expect` is an object.
+  - Add unit tests for new `ObjectContaining` behavior.
+  - Remove `invalid/wrong` test case assertions for `ObjectContaining`.
 
 ### Performance
 
diff --git a/packages/expect/src/__tests__/asymmetricMatchers.test.ts b/packages/expect/src/__tests__/asymmetricMatchers.test.ts
@@ -184,7 +184,6 @@ test('ArrayNotContaining throws for non-arrays', () => {
 test('ObjectContaining matches', () => {
   const foo = Symbol('foo');
   for (const test of [
-    objectContaining({}).asymmetricMatch('jest'),
     objectContaining({foo: 'foo'}).asymmetricMatch({foo: 'foo', jest: 'jest'}),
     objectContaining({foo: undefined}).asymmetricMatch({foo: undefined}),
     objectContaining({first: objectContaining({second: {}})}).asymmetricMatch({
@@ -247,6 +246,18 @@ test('ObjectContaining throws for non-objects', () => {
   );
 });
 
+test('ObjectContaining does not match when non-objects are passed to the expect function as arguments', () => {
+  for (const test of [
+    objectContaining({}).asymmetricMatch('jest'),
+    objectContaining({}).asymmetricMatch(10),
+    objectContaining({}).asymmetricMatch(false),
+    objectContaining({}).asymmetricMatch(undefined),
+    objectContaining({}).asymmetricMatch([]),
+  ]) {
+    jestExpect(test).toEqual(false);
+  }
+});
+
 test('ObjectContaining does not mutate the sample', () => {
   const sample = {foo: {bar: {}}};
   const sample_json = JSON.stringify(sample);
@@ -259,8 +270,6 @@ test('ObjectNotContaining matches', () => {
   const foo = Symbol('foo');
   const bar = Symbol('bar');
   for (const test of [
-    objectContaining({}).asymmetricMatch(null),
-    objectContaining({}).asymmetricMatch(undefined),
     objectNotContaining({[foo]: 'foo'}).asymmetricMatch({[bar]: 'bar'}),
     objectNotContaining({foo: 'foo'}).asymmetricMatch({bar: 'bar'}),
     objectNotContaining({foo: 'foo'}).asymmetricMatch({foo: 'foox'}),
diff --git a/packages/expect/src/asymmetricMatchers.ts b/packages/expect/src/asymmetricMatchers.ts
@@ -233,13 +233,22 @@ class ObjectContaining extends AsymmetricMatcher<
   }
 
   asymmetricMatch(other: any) {
+    // Ensures that the argument passed to the objectContaining method is an object
     if (typeof this.sample !== 'object') {
       throw new TypeError(
         `You must provide an object to ${this.toString()}, not '${typeof this
           .sample}'.`,
       );
     }
 
+    // Ensures that the argument passed to the expect function is an object
+    // This is necessary to avoid matching of non-object values
+    // Arrays are a special type of object, but having a valid match with a standard object
+    // does not make sense, hence we do a simple array check
+    if (typeof other !== 'object' || Array.isArray(other)) {
+      return false;
+    }
+
     let result = true;
 
     const matcherContext = this.getMatcherContext();
