Ticket #38369: 38369.2.diff

src/wp-includes/comment-template.php

@@ -835 +835 @@
  * @since 1.5.0
  *
  * @param int|WP_Post $post_id Optional. Post ID or WP_Post object. Default is global $post.
- * @return int The number of comments a post has.
+ * @return string The number of comments a post has. Numeric string is returned for compatibility reasons.
  */
 function get_comments_number( $post_id = 0 ) {
         $post = get_post( $post_id );
 
         if ( ! $post ) {
-                $count = 0;
+                $count = '0';
         } else {
                 $count = $post->comment_count;
                 $post_id = $post->ID;

tests/phpunit/tests/comment/template.php

@@ -17 +17 @@
                 $this->assertEquals( 12, get_comments_number( get_post( $post_id ) ) );
         }
 
+        function test_get_comments_number_return_type() {
+                $post_id = self::factory()->post->create();
+
+                $this->assertSame( '0', get_comments_number( 0 ) );
+                $this->assertSame( '0', get_comments_number( $post_id ) );
+                $this->assertSame( '0', get_comments_number( get_post( $post_id ) ) );
+
+                self::factory()->comment->create_post_comments( $post_id, 12 );
+
+                $this->assertSame( '12', get_comments_number( $post_id ) );
+                $this->assertSame( '12', get_comments_number( get_post( $post_id ) ) );
+        }
+
         function test_get_comments_number_without_arg() {
                 $post_id = self::factory()->post->create();
                 $permalink = get_permalink( $post_id );