feature: Try and resolve java home if it's a symlink

[tgodzik]

Resolves scalameta/metals-vscode#1094

[kpodsiad]

Is it more readable? I find flat ifs and early return more readable than nesting it

  const cleanJavaHome = configuredJavaHome?.trim();

  if (cleanJavaHome == null) return TE.left({});

  if (cleanJavaHome.length === 0) return TE.left({});

  if (fs.existsSync(cleanJavaHome)) {
    const stat = fs.lstatSync(cleanJavaHome);
    const realpath = fs.realpathSync(cleanJavaHome);
    if (stat.isSymbolicLink() && realpath.endsWith(`bin${path.sep}java`)) {
      const javaHome = path.dirname(path.dirname(realpath));
      return TE.right(javaHome);
    }
  }
  
  return TE.right(cleanJavaHome);

[dos65]

I took a look over conversations about that and I can't that I was convinced that it should work in this way 😸

What about adding an additional fallback function that tries to infer java Home from java in $PATH. Then it should work in the same way but without a setting.
I mean here -

metals-languageclient/src/getJavaHome.ts

Line 31 in 3f88cf1

pipe(fromConfig(configuredJavaHome), TE.orElse(fromEnv), TE.orElse(locate))

[kpodsiad]

I took a look over conversations about that and I can't that I was convinced that it should work in this way 😸

Maybe it's finally time for metals to download own Java? Problems with java home seem to be never ending 😢

[tanishiking]

What about adding an additional fallback function that tries to infer java Home from java in $PATH. Then it should work in the same way but without a setting.

I agree with @dos65
Adding another inference rule based on java on $PATH (the rule should be the same with this PR, resolve symlink and grandparent dir should be its java home).
This inference rule should have the lowest priority, next to the locate-java-home.

---

By the way, maybe we should replace locate-java-home with find-java-home looks like it has the inference rule for the grandparent dir of javac).

[tgodzik]

What about adding an additional fallback function that tries to infer java Home from java in $PATH. Then it should work in the same way but without a setting.

I agree with @dos65 Adding another inference rule based on java on $PATH (the rule should be the same with this PR, resolve symlink and grandparent dir should be its java home). This inference rule should have the lowest priority, next to the locate-java-home.

Och, I didn't think this would be controvertial 😅

By the way, maybe we should replace locate-java-home with find-java-home looks like it has the inference rule for the grandparent dir of javac).

Looks like it does the same thing as this PR, so might be good to use that instead. Let's check it after the next release.