Kape

Kape is a testing framework focused on Developer Experience first. It does this by prioritizing the following concepts as first class citizens:

• Snapshot Testing
• Data Driven Testing
• Behavior Driven Development
• CLI UX
• Promises

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Inception

As a developer that loves the most minimal setup possible with the smallest footprint, I've always been tied to Tape as a testing framework. Over time, Tape was not able to fulfill the needs I had of a testing framework. I really enjoy Behavior Driven Development terminology so to enable that I added in Tape BDD. Following that I really wanted Snapshot Testing as made popular by Jest. While I thought that would be a simple thing to add... it wasn't. While trying snapshot testing, I also really needed promise support and I needed to add Blue Tape. At that moment I realized I needed something to do all of the above.

On top of that growing stack just for testing, I am also a REALLY lazy developer... most of the time I just want to know that a function's output does not change as long as I maintain the same input. I wanted a Snapshot Testing First strategy, that was just not easy to do in any framework. I tried getting Jest to work, but ultimately I got stuck in configuration hell due to the Alle monorepo setup. So instead I decided to write my own framework where all you needed to provide was a set of inputs and the framework would snapshot the output of the function under test by default and always check against the snapshot. And with that Kape was born.

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Usage

The simplest way to use Kape is below:

import describe from 'kape'
import funcUnderTest from './some-function'

describe('Name of Function', funcUnderTest, snapshot =>
    snapshot([], [arg1], [arg1, arg2])
)

The above will run 3 tests. It will run each argument of snapshot as a set of arguments for the given funcUnderTest, after running that it will snapshot the result and save it. If a snapshot already exists, it will validate against the old snapshot, and then ask for verification if any changes are present. Simple as that.