multi_test

write templated tests based on input and output data

example

const mt = require('multi_test').tape;

mt({
    path: '(a|b)*',
    test_func: (test_name, contents, tape) => {
        tape.equal('done', contents['contents']);}});

usage

Multi_test allows you to write better unit tests. For each test, store inputs and expected outputs in separate files. Then use globbing and filtering to load and process them with minimal effort.

Suppose you are testing the following function:

function prefix(i) {
    return 'pre-' + i;
}

Here are the files necessary for three tests:

01_none_before: ''
01_none_after: 'pre-'
02_short_before: 'a'
02_short_after: 'pre-a'
03_long_before: 'multiple\nlines'
03_long_after: 'pre-multiple\nlines'

Here is the code needed to perform those three tests:

mt({
    path: 'data/*before',
    make_groups: path => {
        const root = path.replace('before', '');
        return {
            before: path,
            after: root + 'after'}),
    test_func: (test_name, contents, tape) => {
        tape.equal(
            prefix(contents['before']['contents']),
            contents['after']['contents']);}});

A big advantage of this system, apart from brevity, is that adding further tests does not require modifying code.

parameters

cwd

The starting point when searching for files. Default: '.'.

path

A string which is pattern matched to files using globbing. This is used to find the initial set of files before filtering. Default: '**'.

filters

An array of javascript regular expressions. Any files which match the path glob which do not match every regex are discarded. Default: [].

negative_filters

An array of javascript regular expressions. Any file which matches the path glob but also matches a regex from here are discarded. Default: [].

make_groups

A function which takes the path of a matching file after filtering, and returns an object. The values of this object must be valid file paths.

test_func

A function which is passed the contents of the files as specified above and the tape testing object. It should perform a test using these.

only

Calls the tests with the 'only' method. Therefore, this will only work if the filters produe a unique output.

installation

npm install --save multi_test