Ensure node is accessible before running npm

[jnels124]

Fixes #1185
Please DO NOT FORCE PUSH. Don't worry about messy history, it's easier to do code review if we can tell what happened after the review, and force pushing breaks that.

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• either
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This makes it easier for the maintainers to quickly release your changes :)

[jnels124]

This PR addresses the issue specified in #1185. When setting the npm executable directly and node is not accessible on the $PATH, the npm executable is not able to run. This PR checks to ensure that we are using the node version in the same directory as npm. Admittedly, this change could be implemented to be more flexible and possibly have different path resolvers but not sure that functionality is needed so went with the smallest scope of change possible. Could also just update the process builder to modify the PATH env var to include the parent folder of the npm executable

[simschla]

Thank you for this PR. I'm not sure we can keep the code like this. Two reasons:

1. In Prettier doesn't work if node is not on the PATH #1185 you describe, that you want to use a node installation dynamically retrieved via node-gradle-plugin. With that plugin specifically it is possible, to download npm and node to different locations:

node {
    download = true
    version = '18.13.0'
    npmVersion = '8.19.2'
    workDir = file("${buildDir}/nodejs")
    npmWorkDir = file("${buildDir}/npm")
}

This change would prevent such an installation from ever working with spotless prettier.
2. I think on windows, the node binary is called node.cmd, so this test would probably fail there.

I would suggest to change your PR to detect when the npm process fails due to missing node binary and give the user a very specific error message for this.

Regarding being able to better integrate node-gradle-plugin: I'm currently looking into allowing the user to specify PATH and/or the location of the node binary (triggered by #1381).

[jnels124]

Can update the error message but the problem still remains. NPM can't run without node on the $PATH and that is not desirable. Looks like the work described in #1381 completely solves the issue with executing npm without node being on the System $PATH but there are other issues that need to be solved in order to make the node gradle plugin work for Prettier. I added some comments on #1381 in reference to the additional issues that need to be resolved.

[simschla]

Can update the error message but the problem still remains.
Maybe you misinterpreted what I meant.

I thought of something along the way of

try {
    // npm install is triggered
} catch (Exception e) {
   if (e.getMessage().contains("failed with exit code: 127")) {
      throw new IllegalStateException("Node could not be found on the path, npm is unable to execute.");
  }
}

But with the changes I'm currently doing for #1381, that change would become obsolete. With that said, are you OK if we close this PR?

For the second part of your reply:
I agree with you: we have an issue about config-phase / execution phase when interoperating spotless and gradle-node-plugin. I suggest we raise a new issue for that topic and move discussion there.

[simschla]

Changes in this PR should be obsolete by merging #1500

Better integration of gradle-node-plugin and spotless is discussed in #1499 - feel free to follow there.

Thanks again for the PR, I'm closing without merging.