inline-js-test.php

<?php
/*
Plugin Name: Inline JS Test
Version: 0.1
Author: David Gwyer
*/

// ijst_ prefix is derived from [i]nline [js] [t]est

// Enqueue scripts

function ijst_enqueue_scripts() {
	$options = get_option( 'ijst_options' );
	$js = get_post_meta( '5943', '_ijst-js', true );

	wp_enqueue_script( 'ijst-test', plugins_url('test.js', __FILE__), array(), '', true );

	$inline_js1 = $options['textarea'];
	$inline_js2 = $js;
	wp_add_inline_script( 'ijst-test', $inline_js1 );
	wp_add_inline_script( 'ijst-test', $inline_js2 );
}
add_action( 'wp_enqueue_scripts', 'ijst_enqueue_scripts' );

// Plugin options page

function ijst_init() {
	register_setting( 'ijst_plugin_options', 'ijst_options' );
}
add_action( 'admin_init', 'ijst_init' );

function ijst_add_options_page() {
	$page = add_options_page( 'Inline JS Test', 'Inline JS Test', 'manage_options', __FILE__, 'ijst_render_form' );
}
add_action( 'admin_menu', 'ijst_add_options_page' );

function ijst_render_form() {
	?>
	<div class="wrap">
		<h2 style="font-size: 23px;">Inline JS Test</h2>
		<form method="post" action="options.php">
			<?php
				settings_fields( 'ijst_plugin_options' );
				$options = get_option( 'ijst_options' );
			?>
			<table>
				<tr>
					<td><textarea name="ijst_options[textarea]" rows="7" cols="50" type='textarea'><?php echo $options['textarea']; ?></textarea></td>
				</tr>
			</table>
			<p class="submit"><input type="submit" class="button-primary" value="<?php _e( 'Save Changes' ) ?>"></p>
		</form>
	</div>
<?php
}

// Post meta box

function ijst_meta_box_init() {
	add_meta_box( 'inline-js-test', 'Inline JS Test', 'ijst_render_meta_box', 'post', 'normal', 'high' );
	add_action( 'save_post', 'ijst_save_meta_box_data' );
}
add_action( 'admin_init', 'ijst_meta_box_init' );

function ijst_save_meta_box_data( $post_id ) {
	if ( isset( $_POST['ijst-js'] ) ) { update_post_meta( $post_id, '_ijst-js', esc_attr( $_POST['ijst-js'] ) ); }
}

function ijst_render_meta_box( $post, $args ) {
	$js = get_post_meta( $post->ID, '_ijst-js', true );
	?><table><tr><td><textarea id="ijst-js" name="ijst-js"><?php echo esc_attr( $js ); ?></textarea></td></tr></table><?php
}

test.js

console.log("test.js loaded");