Tests: Use assertSame() in some newly introduced tests.

This ensures that not only the return values match the expected results, but also that their type is the same.

Going forward, stricter type checking by using `assertSame()` should generally be preferred to `assertEquals()` where appropriate, to make the tests more reliable.

Follow-up to [60775], [61131].

See #64324.

git-svn-id: https://develop.svn.wordpress.org/trunk@61370 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

tests/phpunit/tests/menu/wpAjaxMenuQuickSearch.php

@@ -192,6 +192,6 @@ public function test_search_returns_post_types_with_numeric_slugs() {
 		$this->assertCount( 1, $results );
 
 		$results_json = array_map( 'json_decode', $results );
-		$this->assertEquals( 'wptests_123', $results_json[0]->post_type );
+		$this->assertSame( 'wptests_123', $results_json[0]->post_type );
 	}
 }

tests/phpunit/tests/pluggable/wpMail.php

@@ -666,12 +666,12 @@ public function test_wp_mail_encoding_does_not_bleed() {
 		wp_mail( WP_TESTS_EMAIL, 'Looong line testing', $content );
 
 		$mailer = tests_retrieve_phpmailer_instance();
-		$this->assertEquals( 'quoted-printable', $mailer->Encoding );
+		$this->assertSame( 'quoted-printable', $mailer->Encoding );
 
 		wp_mail( WP_TESTS_EMAIL, 'A follow up short email', 'Short email' );
 
 		$mailer = tests_retrieve_phpmailer_instance();
-		$this->assertEquals( '7bit', $mailer->Encoding );
+		$this->assertSame( '7bit', $mailer->Encoding );
 	}
 
 	/**