Add a "Hello from my plugin" message to the admin bar

plugin.php

@@ -1,27 +1,37 @@
 <?php
 /*
-Plugin Name: Mock Plugin
-Description: A simple mock WordPress plugin for testing purposes.
-Version: 1.0.0
-Author: Your Name
+Plugin Name: Hello From My Plugin
+Description: Puts "Hello from my plugin" into the admin bar where Hello, Dolly normally shows quotes.
+Version: 0.1
+Author: You
+Text Domain: hfmp
 */
 
 add_action( 'init', function() {
 } );
 
-add_action( 'wp_head', function() {
-    echo '<script>console.log("hello world");</script>';
-} );
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
-/**/
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/* Replace Hello Dolly's node (if present) and add our own in the admin bar. */
+add_action( 'admin_bar_menu', function( $wp_admin_bar ) {
+	// only run when the admin bar is actually showing
+	if ( ! is_admin_bar_showing() ) {
+		return;
+	}
+
+	// if Hello Dolly exists, remove it so our string takes the same id/position
+	$wp_admin_bar->remove_node( 'hello-dolly' );
+
+	// add a simple, non-linked text node
+	$wp_admin_bar->add_node( [
+		'id'    => 'hello-dolly', // reuse the same id so placement mirrors Hello Dolly
+		'title' => __( 'Hello from my plugin', 'hfmp' ),
+		'href'  => false,
+		'meta'  => [
+			'class' => 'hfmp-hello ab-item',
+			'title' => __( 'Hello from my plugin', 'hfmp' ),
+		],
+	] );
+}, 999 );