Helpers for extending Jest's expect in a type-safe manner in Typescript.
Extending Jest's matchers makes for much easier testing, but convincing Typescript that you've done so is annoying. The types you need are mostly, but not exhaustively, defined in the type stubs but aren't available for import.
This package is mostly type manipulation.
We extract the relevant types from Jest, and package them up into a wrapper
function which calls expect.extend() then returns expect.
Recommended usage follows the pattern in
src/test/expect.ts.
You need an interface which denotes the extra methods you're making available on
the object returned from expect(), and an object implementing the matchers
corresponding to the members of the interface.
Importantly, you don't implement the extension interface: Jest will mangle calls made to it by test code, and call the correct underlying matcher function.
Jest has more documentation on writing custom
matchers.
The utility functions available on this.util are particularly useful for
making nice failure messages.
We use npm versions and GitHub Actions to release.
On your local machine, with main checked out,
run npm version patch or whatever bump is appropriate.
This will create a new commit and a tag starting with v containing the
version.
Push the tag to GitHub.
We protect tags starting with v, so this step may only be undertaken by
repository administrators.
In the GitHub UI, wait until the tag has finished its CI build.
Now we may push the main branch without hitting branch protections.
Do so.
Again in the GitHub UI, find the tag. Use the three dot menu on the tag to create a release. Use the auto-fill button to populate the release notes, and publish the release.
GitHub Actions will now build the release and publish it to NPM.