Very cool! I wish this existed a couple years ago. I was hacking with LSP and a Java language server for a code migration prototype, and I could not even get past the initialization stage. The server (must have been the Eclipse one) didn't seem to respond to the initialization params as expected, and I could not find the right documentation or code snippets to figure it out. I eventually implemented the prototype using OpenRewrite. With this, I'm tempted to revive that idea again.