fix(gatsby): Silence process.send Error

[LekoArts]

Description

As per https://nodejs.org/api/child_process.html#child_process_subprocess_send_message_sendhandle_options_callback:

The optional callback is a function that is invoked after the message is sent but before the child may have received it. The function is called with a single argument: null on success, or an Error object on failure.

If no callback function is provided and the message cannot be sent, an 'error' event will be emitted by the ChildProcess object. This can happen, for instance, when the child process has already exited.

So we provide a callback now so that it doesn't emit an 'error' event.

Related Issues

Fix #28011

[ch35874]

[pieh]

We could also potentially check status of this.process.connected ( https://nodejs.org/api/child_process.html#child_process_subprocess_connected ) which should let us know ahead of time wether we still send IPC messages (tho we probably should leave error handler)

[LekoArts]

Which additional benefit would give us that? 🤔

When adding a log before the try/catch we get:

success Writing page-data.json files to public directory -
0.200s - 3/5 24.95/s

^C
{ isConnected: true }                                       
{ isConnected: true }

{ isConnected: false }

minimal on  main [!?] is 📦 v1.0.0 via ⬢ v14.16.1 took 13s 
➜ 

But without the error handler we get:

success Writing page-data.json files to public directory -
0.184s - 3/5 27.10/s

^C
{ isConnected: true }                                         
{ isConnected: true }

 ERROR 

UNHANDLED REJECTION write EPIPE



  Error: write EPIPE
  
  - child_process.js:832 ChildProcess.target._send
    internal/child_process.js:832:20
  
  - child_process.js:703 ChildProcess.send
    internal/child_process.js:703:19
  
  - develop.ts:135 ControllableScript.stop
    [minimal]/[gatsby]/src/commands/develop.ts:135:22
  
  - develop.ts:540 shutdownServices
    [minimal]/[gatsby]/src/commands/develop.ts:540:28
  
  - develop.ts:467 process.<anonymous>
    [minimal]/[gatsby]/src/commands/develop.ts:467:11
  


{ isConnected: true }
{ isConnected: true }

minimal on  main [!?] is 📦 v1.0.0 via ⬢ v14.16.1 took 10s 
➜ 

So the error handler is really doing the work here 😆

[vladar]

Thanks 👍

[LekoArts]

Published in gatsby@3.11.1