How to convert local file path to a file::?/ url safely in node.js?

Use the file-url module.

npm install --save file-url

Usage:

var fileUrl = require('file-url');

fileUrl('unicorn.jpg');
//=> file:///Users/sindresorhus/dev/file-url/unicorn.jpg 

fileUrl('/Users/pony/pics/unicorn.jpg');
//=> file:///Users/pony/pics/unicorn.jpg

Also works in Windows. And the code is simple enough, in case you want to just take a snippet:

var path = require('path');

function fileUrl(str) {
    if (typeof str !== 'string') {
        throw new Error('Expected a string');
    }

    var pathName = path.resolve(str).replace(/\\/g, '/');

    // Windows drive letter must be prefixed with a slash
    if (pathName[0] !== '/') {
        pathName = '/' + pathName;
    }

    return encodeURI('file://' + pathName);
};

Node.js v10.12.0 just got two new methods to solve this issue:

const url = require('url');
url.fileURLToPath(url)
url.pathToFileURL(path)

Documentation

• https://nodejs.org/api/url.html#url_url_pathtofileurl_path
• https://nodejs.org/api/url.html#url_url_fileurltopath_url