JSFiddle - React, Tailwind, and code Playground

by dtracers

JavaScript

cases = ['<br>', // 0
             '   ', // 1
             '\n', // 2
             '\n', // 3
             '', // 4
            '\n\nword<br><br>',// 5 true cases
             ' normal\n<br>\ncomment', // 6
             ' normal comment.', //7
             ' normal_comment ', //8
            'word<br>'];//9

console.log('---------------------------------');
for (var i=0; i<cases.length; i++) {
        var str = cases[i].replace(/\A\s*(<br>\s*)+/g, ""); // start line remover
		str = str.replace(/\s*(<br>\s*)+\z/g, ""); // end line remover
		str = str.trim();
    console.log(cases[i],str);
}