Reverse Express routes.

reverse.js

'use strict';

var assert = require('assert');
var path2regex = require('path-to-regexp');


function reverse(route, obj) {
    var keys;

    keys = [];
    path2regex(route, keys);

    keys.forEach(function (key) {
        var value, regex;

        value = obj[key.name];
        regex = '\\:' + key.name;

        if (key.optional) {
            // Include the trailing '?' in the replacement.
            regex += '\\?';
            if (value === undefined) {
                // No value so remove potential trailing '/'
                // since the path segment is optional.
                value = '';
                regex += '\\/?';
            }
        } else if (value === undefined) {
            value = '';
        }

        route = route.replace(new RegExp(regex, 'g'), value);
    });

    return route;
}



var path, actual;

path = '/foo/bar/:baz';
actual = reverse(path, { baz: 10 });
assert.equal(actual, '/foo/bar/10');

path = '/foo/bar/:baz?';
actual = reverse(path, { baz: 10 });
assert.equal(actual, '/foo/bar/10');

actual = reverse(path, { baz: undefined });
assert.equal(actual, '/foo/bar/');

path = '/foo/:bar/:baz?/';
actual = reverse(path, { bar: 10, baz: 'abc' });
assert.equal(actual, '/foo/10/abc/');

path = '/foo/:bar/:baz?';
actual = reverse(path, { bar: 10, baz: undefined });
assert.equal(actual, '/foo/10/');

path = '/foo/:bar?/:baz';
actual = reverse(path, { bar: undefined, baz: 'abc' });
assert.equal(actual, '/foo/abc');