// @flow

/* Reads HTML into a string */
const readFromHtml = (templateName: string): string => {
    const pathToHtml = 'path/to/html';
    const file = fs.readFileSync(pathToHtml, 'utf8');
    return file;
};

/* Creates function that defines parameters in string literal */
const createTemplate = (stringLiteral: string, ...params: any): Function => {
    return new Function(params, 'return `' + stringLiteral + '`;');
};

const htmlString = readFileHtml() // "Hello, my name is ${firstName} ${lastName}";
const template = createTemplate(htmlString, 'firstName', 'lastName');

console.log(template('Brandon', 'Fujii')); // Hello, my name is Brandon Fujii