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

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({
@@ -228,7 +227,6 @@ test('ObjectContaining matches defined properties', () => {
 test('ObjectContaining matches prototype properties', () => {
   const prototypeObject = {foo: 'bar'};
   let obj;
-
   if (Object.create) {
     obj = Object.create(prototypeObject);
   } else {
@@ -247,6 +245,18 @@ 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 +269,6 @@ 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'}),

packages/expect/src/asymmetricMatchers.ts

@@ -227,13 +227,22 @@ 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();