Simple cases conversion using JavaScript

convertCases.js

/* Using functional programming to convert cases */
function convertCase(text, callback) {
    return callback.apply(null, [text]);
}

/* convert_to_snake_case */
function snakeCase(text) {
    return text.replace(/\s+/g, '_').toLowerCase();
}

/* ConvertToCamelCase */
function camelCase(text) {
    return text
        .replace(/\s([a-z])/g, function($1) { return $1.toUpperCase() })
        .replace(/\s/g, '')
        .replace(/^([A-Z])/, function($1) { return $1.toLowerCase() });
}

/* CONVERT_TO_CONSTANT_CASE */
function constantCase(text) {
    var result = convertCase(text, snakeCase);
    return result.toUpperCase();
}

/* ConvertPascalCase */
function pascalCase(text) {
    return convertCase(text, camelCase)
        .replace(/^([a-z])/, function($1) { return $1.toUpperCase(); });
}

/* CoNvErTtOtOgGlEcAsE */
function toggleCase(text) {
    var lowerCase = text[0].match(/[a-z]/) == null;
    var arrText = text.split('');
    arrText.forEach(function(item, index) {
        arrText[index] = lowerCase ? item.toUpperCase() : item.toLowerCase();
        lowerCase = !lowerCase;
    });
    return arrText.join('');
}

var strTest = "insert a test here";

console.log("snake_case:\n\t" + convertCase(strTest, snakeCase));
console.log("camelCase:\n\t"  + convertCase(strTest, camelCase));
console.log("CONSTANT_CASE:\n\t"  + convertCase(strTest, constantCase));
console.log("PascalCase:\n\t"  + convertCase(strTest, pascalCase));
console.log("tOgGlEcAsE:\n\t"  + convertCase(strTest, toggleCase));