Os espelhos de código se aplicam a todas as textaras
var textareas = document.querySelectorAll(".textarea-class");
for (var i = 0; i < textareas.length; i++) {
CodeMirror.fromTextArea(textareas[i], {
lineWrapping: true,
mode: "javascript",
theme: "neat",
lineNumbers: true
});
}
Friendly Hawk