Add tests

tests/phpunit/helper-functions/test-class-admin.php

@@ -30,7 +30,7 @@ public static function set_up_before_class() {
 	}
 
 	/**
-	 * Tests class constructor.
+	 * Tests hooks registration.
 	 *
 	 * @covers Admin::register_hooks
 	 */
@@ -42,4 +42,31 @@ public function test_register_hooks() {
 		$this->assertSame( 10, has_action( 'manage_post_tag_custom_column', [ self::$class_instance, 'manage_tag_columns' ] ), 10, 3 );
 		$this->assertSame( 10, has_action( 'tag_row_actions', [ self::$class_instance, 'remove_view_action' ] ), 10, 2 );
 	}
+
+	/**
+	 * Tests settings registration.
+	 *
+	 * @covers Admin::register_settings
+	 */
+	public function test_register_settings() {
+		self::$class_instance->register_settings();
+
+		global $wp_settings_sections, $wp_settings_fields;
+
+		$this->assertArrayHasKey( 'fewer_tags_section', $wp_settings_sections );
+		$this->assertArrayHasKey( 'joost_min_posts_count', $wp_settings_fields );
+	}
+
+	/**
+	 * Tests display section.
+	 *
+	 * @covers Admin::display_section
+	 */
+	public function test_display_section() {
+		ob_start();
+		self::$class_instance->display_section();
+		$output = ob_get_clean();
+
+		$this->assertSame( 'Set the minimum number of posts a tag should have to become live on the site and not be redirected to the homepage.', $output );
+	}
 }