Use of Jest CLI in Node scripts

[eldarshamukhamedov]

Hey all, hopefully someone can help me out with a less common use case for Jest. I am writing a set of build/deploy scripts that start by running Jest, before continuing to compile and dockerize an application. Unfortunately, there does not appear to be a public API to match Jest CLI functionality. How can I run Jest from a Node script?

I did find an example in Create React App's test script. The problem with this approach is that jest.run() spawns a new process. This process will exit cleanly if all tests pass, and errors out if some tests fail. That's good enough for a CLI command, but jest.run() does not return a promise, or event stream, so there's no way to detect when and how the Jest process exits from my code.

The workaround I'm currently using is to spawn a new process that runs Jest. Since I control how the process is spawned, I can wrap it in a promise that rejects/resolves based on the Jest process exit code. This feels a bit clunky, since I am spawning a process for my build script that immediately spawns another process for Jest. Is there a better way? Is there documentation that I missed?

[cpojer]

There is an onComplete event that isn't expose to run. Would you mind sending a PR to add that?

[eldarshamukhamedov]

That would work, and yeah, I can put up a PR. I'm thinking, if you pass jest.run() a callback as the final argument, it could call that with the result, instead of exiting the process.

[rogeliog]

@eldarshamukhamedov This is the onComplete callback that runCLI is already using.... I think we just need to pass it all the way down when running jest.run

[eldarshamukhamedov]

@rogeliog Yep, I got eldarshamukhamedov@931927f, just need to write the tests.

[rogeliog]

Awesome, I left some comments

[fijijavis]

Did this get implemented?

[SimenB]

No. Feel free to send a PR 🙂

[SaurabhKhare86]

I'm also facing this issue. I'm using runCLI function of jest-cli and tests are executing, but unable to know when exactly test run gets finished. I'm resolving the promise with a then function, but my then function code executes first and then the test run completes.

I checked out the source code and looks like there is no event / callback as of now which notifies the complete of test execution.

If this is a open issue - Is there a workaround? It's said above that we can spawn a new process, but I'm new to Node and need some help in figuring out how to achieve that.

To fix this issue, is the approach taken here still correct ?

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