feat(java): add test and debug support for Java extension (#1192)

lua/lazyvim/plugins/extras/lang/java.lua

@@ -9,6 +9,21 @@ return {
     end,
   },
 
+  -- Ensure java debugger and test packages are installed
+  {
+    "mfussenegger/nvim-dap",
+    optional = true,
+    dependencies = {
+      {
+        "williamboman/mason.nvim",
+        opts = function(_, opts)
+          opts.ensure_installed = opts.ensure_installed or {}
+          vim.list_extend(opts.ensure_installed, { "java-test", "java-debug-adapter" })
+        end,
+      },
+    },
+  },
+
   -- Set up lsp with mfussenegger/nvim-jdtls instead of nvim-lspconfig.
   {
     "neovim/nvim-lspconfig",
@@ -38,7 +53,25 @@ return {
           local lsp_config = require("lspconfig.server_configurations.jdtls").default_config
           local find_java_project_root = lsp_config.root_dir
           local filetypes = lsp_config.filetypes
-
+          -- lookup paths for java test and debugger package
+          local mason_registry = require("mason-registry")
+          local bundles = {}
+          if mason_registry.has_package("java-test") and mason_registry.has_package("java-debug-adapter") then
+            -- jdtls tools configuration for debugging support
+            local java_test_pkg = mason_registry.get_package("java-test")
+            local java_test_path = java_test_pkg:get_install_path()
+            local java_dbg_pkg = mason_registry.get_package("java-debug-adapter")
+            local java_dbg_path = java_dbg_pkg:get_install_path()
+            local jar_patterns = {
+              java_dbg_path .. "/extension/server/com.microsoft.java.debug.plugin-*.jar",
+              java_test_path .. "/extension/server/*.jar"
+            }
+            for _, jar_pattern in ipairs(jar_patterns) do
+              for _, bundle in ipairs(vim.split(vim.fn.glob(jar_pattern), '\n')) do
+                table.insert(bundles, bundle)
+              end
+            end
+          end
           -- Attach jdtls for the proper filetypes (i.e. java).
           -- Existing server will be reused if the root_dir matches.
           vim.api.nvim_create_autocmd("FileType", {
@@ -58,14 +91,32 @@ return {
                   vim.fs.joinpath(jdtls_cache_dir, "workspace"),
                 })
               end
-              require("jdtls").start_or_attach({
+              local jdtls_base_config = {
+                on_attach = require("lazyvim.util").on_attach(function(client, buffer)
+                  if mason_registry.has_package("java-test") then
+                    -- custom keymaps for Java test runner (not yet compatible with neotest)
+                    vim.keymap.set("n", "<leader>tT", function() require("jdtls").pick_test({ bufnr = buffer }) end, { buffer = buffer, desc = "Run specific Test" })
+                    vim.keymap.set("n", "<leader>tt", function() require("jdtls").test_class({ bufnr = buffer }) end, { buffer = buffer, desc = "Run File" })
+                    vim.keymap.set("n", "<leader>tr", function() require("jdtls").test_nearest_method({ bufnr = buffer }) end, { buffer = buffer, desc = "Run nearest" })
+                  end
+                  if mason_registry.has_package("java-debug-adapter") then
+                    -- custom init for Java debugger
+                    require("jdtls").setup_dap({ hotcodereplace = "auto" })
+                    require("jdtls.dap").setup_dap_main_class_configs()
+                  end
+                  require("jdtls.setup").add_commands()
+                end),
                 cmd = cmd,
                 root_dir = root_dir,
-              })
+                init_options = {
+                  bundles = bundles,
+                }
+              }
+              local jdtls_opts = require("lazyvim.util").opts("nvim-jdtls")
+              require("jdtls").start_or_attach(vim.tbl_deep_extend("force", jdtls_opts or {}, jdtls_base_config))
               require("which-key").register({ c = { x = { name = "Extract" } } }, { prefix = "<leader>" })
             end,
           })
-
           return true -- avoid duplicate servers
         end,
       },