How is JEST_METADATA_SERVER being shared between parent process and child worker process?

[madcapnmckay]

I'm trying to understand the code. I see JEST_METADATA_SERVER being set by registerServerId, which looks like it would occur during the reporter/parent process. But when not running in band process.env, it would not be present in the environment.

Thanks

[noomorph]

Hello, @madcapnmckay !

I'm not sure I have understood your question completely, but I try to set JEST_METADATA_SERVER very early, before Jest even creates child worker processes — this automatically grants us passing process.env as we mutate it. Therefore, any child worker spawned by Jest should "inherit" that JEST_METADATA_SERVER from the first second of life.

We actually used the same trick with the Detox IPC server in Detox 20.0.0+, and so far, it has worked okay.

P.S. I apologize for the delay with addressing your comment — it must have slipped under the radar, and I noticed it just now when releasing another fix.