CODEWITHSUNDEEP
javascriptlocaleyargs
robotburrito
robotburrito

Reputation: 11

How do I unit test that an application using yargs provides the proper responses in multiple locales/languages?

I am working on a command line application that uses yargs to process options passed to that application and operates in a variety of languages.

Testing fails when using non English locales because the expected results for the test are hard coded in that language.

For example the following code returns a passed test in English, however will fail if the language is set to French as Yargs is returning the error in French.

it('call config with no arguments', () => {
      return app('config')
        .then(out => expect(out).to.include('Not enough non-option arguments: got 0, need at least 1'))
})

This brings me to my question. What is best practice to handle a situation like this? I have been digging into Yargs and even the y18n package that it uses for translation and see no necessarily straight forward way to handle this problem.

I imagine a possible solution would be to have the string that the test expects be translated perhaps via the y18n library, or perhaps having a test for every supported language, however that could be quite overkill.

What have you done in such a situation? I would love to know!

Thanks!

Upvotes: 1

Views: 1159

Answers (1)

andrewdotn
andrewdotn

Reputation: 34873

Yargs has a locale() method which you could use to set the locale during testing.

One way to do this with a local wrapper module would be:

app.js:

const yargs = require('./my-yargs');

...
args = yargs.option(...)...
...

my-yargs.js:

let yargs = require('yargs');
if (process.env.NODE_ENV === 'test') {
    yargs = yargs.locale('en')
}
module.exports = yargs;

Which would result in the following output:

$ LC_ALL=fr_FR.UTF-8 node test.js --help
Options:
--help     Affiche de l'aide                                         [booléen]
--version  Affiche le numéro de version                              [booléen]

$ NODE_ENV=test LC_ALL=fr_FR.UTF-8 node test.js --help
Options:
--help     Show help                                                 [boolean]
--version  Show version number                                       [boolean]

Upvotes: 1

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