Adding Eslint LSP component (#4)

config/components.yml

@@ -58,4 +58,6 @@ frameworks:
   - "JavaBuildpack::Framework::YourKitProfiler"
   - "JavaBuildpack::Framework::JavaOpts"
   - "JavaBuildpack::Framework::LanguageServerBinExecJDT"
+  - "JavaBuildpack::Framework::LanguageServerNodeESLINT"
+
 # - "JavaBuildpack::Framework::LanguageServerNodeCDX"

config/language_server_node_eslint.yml

@@ -0,0 +1,11 @@
+# TODO License.
+
+# Configuration for the JAVA LSP server component
+---
+version: 0.0.+
+repository_root: "https://lsp-component-eslint.cfapps.eu10.hana.ondemand.com/"
+env:
+    workdir: language_server_node_eslint/server/
+    exec: language_server_node_eslint/launcher.sh
+    ipc:
+        protocol: "stream"

lib/java_buildpack/framework/language_server_node_eslint.rb

@@ -0,0 +1,86 @@
+# Encoding: utf-8
+# TODO License.
+
+require 'java_buildpack/component/versioned_dependency_component'
+require 'java_buildpack/framework'
+require 'fileutils'
+require 'java_buildpack/util/qualify_path'
+require 'java_buildpack/logging/logger_factory'
+
+module JavaBuildpack
+  module Framework
+
+    # Installs ESLINT based LSP server component.
+    class LanguageServerNodeESLINT < JavaBuildpack::Component::VersionedDependencyComponent
+
+      # Creates an instance
+      #
+      # @param [Hash] context a collection of utilities used the component
+      def initialize(context)
+        super(context)
+        @logger = JavaBuildpack::Logging::LoggerFactory.instance.get_logger LanguageServerNodeESLINT
+      end
+
+
+      # (see JavaBuildpack::Component::BaseComponent#compile)
+      def compile
+        @logger.debug { "Compile ESLINT" }
+        # Install node js
+        FileUtils.mkdir_p @droplet.root + "nodejs"
+        nodedir = @droplet.sandbox + "nodejs"
+        comp_version = @version
+        comp_uri = @uri
+        @version="8.0.0"
+        @uri="https://buildpacks.cloudfoundry.org/dependencies/node/node-8.0.0-linux-x64-ade5a8e5.tgz"
+        download_tar( target_directory=nodedir )
+        @version = comp_version
+        @uri = comp_uri
+        download_zip strip_top_level = false
+        @droplet.copy_resources
+
+      end
+
+      # (see JavaBuildpack::Component::BaseComponent#release)
+      def release
+
+        @logger.debug { "Release ESLINT" }
+        environment_variables = @droplet.environment_variables
+        myWorkdir = @configuration["env"]["workdir"]
+        environment_variables.add_environment_variable(ENV_PREFIX + "workdir", myWorkdir)
+        myExec = @configuration["env"]["exec"]
+        environment_variables.add_environment_variable(ENV_PREFIX + "exec", myExec)
+
+        myIpc = @configuration["env"]["ipc"]
+        @logger.debug { "ESLINT Env vars IPC:#{myIpc}" }
+        myIpc.each do |key, value|
+          environment_variables.add_environment_variable(ENV_PREFIX + key, value)
+        end
+
+        environment_variables.add_environment_variable 'PATH', "/home/vcap/app/.java-buildpack/#{@droplet.component_id}/nodejs/bin:$PATH"
+      end
+
+      protected
+
+      # (see JavaBuildpack::Component::VersionedDependencyComponent#supports?)
+      def supports?
+        @application.environment.key?(LSPSERVERS) &&  @application.environment[LSPSERVERS].split(',').include?("eslint")
+      end
+
+      private
+
+      LSPSERVERS = 'lspservers'.freeze
+
+      private_constant :LSPSERVERS
+
+      BINEXEC = 'exec'.freeze
+
+      private_constant :BINEXEC
+
+      ENV_PREFIX = 'LSPESLINT_'.freeze
+
+      private_constant :ENV_PREFIX
+
+    end
+
+  end
+end

resources/language_server_node_eslint/launcher.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exec ../nodejs/bin/node ./out/server.js --stdio