fit_page_to_tf.jsx

var doc = app.documents.add();
var page = doc.pages.item(0);
var tf = page.textFrames.add({
    geometricBounds:[12.7,12.7,100,210],
    contents: "Hi God, it's me - Jesus."
    });
   
    tf.paragraphs.item(0).pointSize = 42;
    tf.fit(FitOptions.FRAME_TO_CONTENT);
    
   

    doc.documentPreferences.pageWidth = tf.geometricBounds[3] + 12.7;
    doc.documentPreferences.pageHeight = tf.geometricBounds[2] + 12.7;
    
    var new_pw = doc.documentPreferences.pageWidth;
    var new_ph = doc.documentPreferences.pageHeight;
    
    tf.geometricBounds = [12.7,12.7,new_ph - 12.7,new_pw - 12.7];