Fix deprecation notice in Fieldmanager_TextArea when default value is…

…n't set

php/class-fieldmanager-textarea.php

@@ -17,6 +17,13 @@ class Fieldmanager_TextArea extends Fieldmanager_Field {
 	 */
 	public $field_class = 'text';
 
+	/**
+	 * The default value for the field, if unset.
+	 *
+	 * @var mixed Default value
+	 */
+	public $default_value = '';
+
 	/**
 	 * Construct default attributes; 50x10 textarea.
 	 *

tests/php/bootstrap.php

@@ -39,3 +39,4 @@ function _fm_phpunit_is_wp_at_least( $min_version ) {
 // Load includes.
 require_once __DIR__ . '/includes/class-fieldmanager-assets-unit-test-case.php';
 require_once __DIR__ . '/includes/class-fieldmanager-options-mock.php';
+require_once __DIR__ . '/includes/class-fieldmanager-deprecation-exception.php';

tests/php/includes/class-fieldmanager-deprecation-exception.php

@@ -0,0 +1,6 @@
+<?php
+/**
+ * An exception class that triggers on expected deprecations
+ */
+
+class Fieldmanager_Deprecation_Exception extends Exception {}

tests/php/test-fieldmanager-textarea-field.php

@@ -0,0 +1,81 @@
+<?php
+
+/**
+ * Tests the Fieldmanager TextArea Field
+ *
+ * @group field
+ * @group textarea
+ */
+class Test_Fieldmanager_TextArea_Field extends WP_UnitTestCase {
+
+	/**
+	 * The post ID of the test post.
+	 *
+	 * @var int
+	 */
+	private int $post_id = 0;
+
+	/**
+	 * The post object of the test post.
+	 *
+	 * @var WP_Post
+	 */
+	private WP_Post $post;
+
+	public function set_up() {
+		parent::set_up();
+		Fieldmanager_Field::$debug = true;
+
+		$this->post_id = $this->factory->post->create(
+			array(
+				'post_title' => rand_str(),
+				'post_date'  => '2024-02-29 00:00:00',
+			)
+		);
+		$this->post    = get_post( $this->post_id );
+	}
+
+	/**
+	 * Test to confirm that not defining a default value for a field
+	 * does not cause that field to throw a deprecation warning when
+	 * a textarea field is used.
+	 *
+	 * @see https://github.com/alleyinteractive/wordpress-fieldmanager/issues/863
+	 */
+	public function test_default_value_does_not_throw_deprecation() {
+		set_error_handler(
+			/**
+			 * Convert deprecations to exceptions. This was removed from PHPUnit in
+			 * PHPUnit 10, so doing so manually here for future compatibility.
+			 *
+			 * @see https://github.com/sebastianbergmann/phpunit/issues/5062
+			 */
+            function ( $errno, $errstr ) {
+                throw new Fieldmanager_Deprecation_Exception( $errstr, $errno );
+            },
+            E_DEPRECATED | E_USER_DEPRECATED
+        );
+
+		$this->expectNotToPerformAssertions();
+
+		try {
+			ob_start();
+
+			$fm = new Fieldmanager_Textarea(
+				[
+					'name'          => 'example-textarea',
+					'description'   => 'Description Text',
+				]
+			);
+			$fm->add_meta_box( 'Test TextArea', 'post' )
+				->render_meta_box( $this->post, array() );
+
+			ob_get_clean();
+		} catch( Fieldmanager_Deprecation_Exception $e ) {
+			$this->fail( $e->getMessage() );
+		}
+
+		// Restore default error handler.
+		restore_error_handler();
+	}
+}