wp-includes/deprecated.php:3418Determine if TinyMCE is available.
boolfunction rich_edit_exists() { global $wp_rich_edit_exists; _deprecated_function( __FUNCTION__, '3.9.0' ); if ( ! isset( $wp_rich_edit_exists ) ) $wp_rich_edit_exists = file_exists( ABSPATH . WPINC . '/js/tinymce/tinymce.js' ); return $wp_rich_edit_exists;}Introduced in 2.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.