Bazel Support

[notpeter]

I think it would be possible to support bazel with jdtls, just as salesforce/bazel-vscode-java provides jars via contributes.javaExtensions to redhat-developer/vscode-java which get injected into the jdtls initializationOptions.bundles

The salesforce/bazel-vscode-java extension downloads p2-repository.zip which it then extracts, does some renaming and puts them under ~/.vscode/extensions/sfdc.bazel-vscode-java-1.4.0/server. And since salesforce/bazel-vscode-java exports a list of those jars via contributes.javaExtensions in it's package.json those settings are available to other extensions.
Source: salesforce/bazel-vscode-java:gulpfile.js and salesforce/bazel-vscode-java:package.json

When redhat-developer/vscode-java starts the language server it pulls from contributes.javaExtensions and provides those as a bundles array under the initializationOptions when starting jdtls:
Source: redhat-developer/vscode-java:src/extension.ts

I think the Zed Java Extension could potentially add support for Bazel with the following settings:

{
  "lsp": {
    "jdtls": {
      "initialization_options": {
        "bundles": [
          "somepath/org.eclipse.equinox.event.jar",
          "somepath/com.github.ben-manes.caffeine.jar",
          "somepath/org.jsr-305.jar",
          "somepath/org.fusesource.jansi.jar",
          "somepath/com.google.protobuf.jar",
          "somepath/com.salesforce.bazel.importedsource.jar",
          "somepath/com.salesforce.bazel.sdk.jar",
          "somepath/com.salesforce.bazel.eclipse.core.jar",
          "somepath/com.salesforce.bazel.eclipse.jdtls.jar"
        ]
      }
    }
  }
}

Totally untested but I wanted to document my research somewhere.

Not sure whether the current Extension APIs are sufficient to support downloading arbitrary zip files, extracting a subset of them and then injecting the correct pathing for where those files are. But assuming this works, we could certainly provide instructions doing this manually.

I'm not a Java programmer.
I have no experience with Bazel.
Would love if someone can see if they can get this working.

See also:

• Java jdt.ls with Bazel project: Diagnostics going crazy; number spins up and down zed-industries/zed#21265
• Add bazel support eclipse-jdtls/eclipse.jdt.ls#543

[valentinegb]

This would seem perfectly implementable to me, but unfortunately, as far as I'm aware¹, there isn't a way to have an extension modify the initialization options before they're passed to the language server :(

Footnotes

1. emphasized because I don't know everything and I'd love to be proven wrong! ↩

[notpeter]

We definitely fiddle that for the non-extension languages (json, yaml, etc) but I think you're right. :(

I think that's worth consider adding an API for.