mariofusco / drools-lsp

This is an experimental implementation of LSP based project intended to provide support for a DRL text editor.

It is composed of 2 parts: the server containing the actual LSP implementation and the client which is a VSCode extension consuming the services provided by the server.

The server is a plain Java/Maven project. Executing a mvn clean package in its folder will generate a jar file that will be automatically linked and consumed by the client when executed as a VSCode extension.

Server Architecture

The server part is composed of three modules:

1. drools-parser
2. drools-completion
3. drools-lsp-server

drools-parser is responsible for actual drl-syntax parsing, eventually invoking a JAVA-LSP engine to read the RHS content (that is plain Java code); it depends on org.drools:drools-drl-ast

drools-completion is used to provide completion suggestion using the C3 engine; it depends on com.vmware.antlr4-c3:antlr4-c3 and on drools-parser

drools-lsp-server is the "gateway" between the client and the parsing/completion logic; by itself it should not implement any business logic, but should be concerned only with communication; it depends directly on drools-completion

Usage

Precompiled-server - no debug

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1. package server side code with mvn clean package
2. goto client directory
3. issue npm install
4. issue code . to start VSCODE in that directory
5. inside VSCODE, select Run and Debug (Ctrl+Shift+D) and then start Run Extension
6. a new Extension Development Host window will appear, with drl extension enabled
7. to "debug" server-side event, add server.getClient().showMessage(new MessageParams(MessageType.Info, {text})); in server-side code

Connected remote server - debug

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1. package server side code with mvn clean package
2. start server with DroolsLspTCPLauncher from IDE on debug mode; this will start the LSP-server listening on port 9925
3. goto client directory
4. issue npm install
5. issue code . to start VSCODE in that directory
6. inside VSCODE, select Run and Debug (Ctrl+Shift+D) and then start Debug Extension
7. the extensions will establish a connection to the server running at port 9925
8. a new Extension Development Host window will appear, with drl extension enabled
9. to "debug" server-side event, add breakpoints in server-side code