Non-JDT errors are not reported in Java files

[fbricon]

Some context
I'm trying to get JBang scripts work OOTB in VS Code. Since the classpath dependencies are coded right in the Java file, I use a similar mechanism to invisible projects to create a Java project under the jdt.ls workspace, that is then augmented with informations gathered from the JBang directives in the original file. This is based on jbang-eclipse. The jdt.ls integration is currently living on my fork. Finally, the VS Code Java integration can be found at https://github.com/fbricon/vscode-jbang, one can install a CI build of the vscode-jbang.vsix from the latest release page.

Now.

When I open a folder containing a JBang script, say hello.java:

///usr/bin/env jbang "$0" "$@" ; exit $?
//DEPS com.github.lalyos:jfiglet:0.0.9
//DEPS org.slf4j:slf4j-api:1.7.32
//JAVA 17
import com.github.lalyos.jfiglet.FigletFont;

class hello {

    public static void main(String... args) throws Exception {
        System.out.println(FigletFont.convertOneLine(
                "Hello " + ((args.length > 0) ? args[0] : "jbang")));
    }

}

When I change the version of a dependency to something invalid, eg. com.github.lalyos:jfiglet:6.6.6, jbang-eclipse adds a JBang error marker to the offending dependency, underlying the error. At least it works in Eclipse. But with jdt.ls, no diagnostic is reported to the client.

In https://github.com/eclipse/eclipse.jdt.ls/blob/a996b57495a150f31c8c2e61110ce8032086f2a1/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/WorkspaceDiagnosticsHandler.java#L169, if the file is a java-like file and not a working copy, all its JAVA_MODEL_PROBLEM_MARKER and TASK_MARKER problems are reported. My jbang errors are thus ignored.