Testing Helpers That Use Scoped Translations

Update: While this technique is useful when you actually need to bind a template to your helper test, most of the time you can simply stub the helper right there, using something like stub(self).t('.title') { "Title" }

Once on a beautiful day the sun was shining and the room was full of pleasant warmth. I was whistling a tune happily to myself while writing the following rails helper.

It’s so neat and simple. It allows you to write title "English Title" and provides a way to override title with translation scoped like pages.index.title.

Then came the test (apologies, TDD purists). Whistling along with the chirping birds I put the following in my helper test.

Suddenly the birds went silent. The room got colder and darker. I got an error.

Here’s what happened. Using scoped translations such as t('.title') requires a template. It makes perfect sense because scope can only be looked up for a particular template’s path. After some research I found that it’s quite easy to stub a template for tests to work. You can put something like this in your setup method.

This is the kind of usefulness that could easily be made into a helper. You can put this in your test_helper.rb.

Now my test looks very neat.

Running tests… Green! And birds are back!