feat: migrate to vim.lsp.config #3659

Problem:
Nvim 0.11 has vim.lsp.config, which mostly replaces the legacy
nvim-lspconfig "framework".

Solution:
Migrate all configs to `lsp/*` variants. The old configs in
`lua/lspconfig/` are "frozen".

The new configs include these changes:
- `commands` field became raw calls to
  `vim.api.nvim_buf_create_user_command` inside `on_attach`.
- `root_dir` became:
  - `root_markers` whenever the file list was simple didn't need to mach `*`
  - if the logic was complicated, or needed to match something like
    '\*.c', it was defined as a vim.lsp.Config `root_dir` callback.
- `on_config_change` became `before_init`. I don't actually know if this
  is the correct approach, but looking around the documentation of
  `nvim-lspconfig` a saw that it was defined as the function that gets
  called as soon as the config have `root_dir`, and so I thought
  `before_init` might be the closest alternative.
- `docs.description` became a luadoc `@brief` docstring.
- `single_file_support = false`?

Co-authored-by: Aliou Diallo <aliou@users.noreply.github.com>
Co-authored-by: Justin M. Keyes <justinkz@gmail.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/lsp/kotlin_language_server.lua b/lsp/kotlin_language_server.lua
new file mode 100644
index 00000000..950ef017
--- /dev/null
+++ b/lsp/kotlin_language_server.lua
@@ -0,0 +1,44 @@
+local util = require 'lspconfig.util'
+
+local bin_name = 'kotlin-language-server'
+
+--- The presence of one of these files indicates a project root directory
+--
+--  These are configuration files for the various build systems supported by
+--  Kotlin. I am not sure whether the language server supports Ant projects,
+--  but I'm keeping it here as well since Ant does support Kotlin.
+local root_files = {
+  'settings.gradle', -- Gradle (multi-project)
+  'settings.gradle.kts', -- Gradle (multi-project)
+  'build.xml', -- Ant
+  'pom.xml', -- Maven
+  'build.gradle', -- Gradle
+  'build.gradle.kts', -- Gradle
+}
+
+---@brief
+---
+---A kotlin language server which was developed for internal usage and
+-- released afterwards. Maintaining is not done by the original author,
+-- but by fwcd.
+
+-- It is built via gradle and developed on github.
+-- Source and additional description:
+-- https://github.com/fwcd/kotlin-language-server
+
+-- This server requires vim to be aware of the kotlin-filetype.
+-- You could refer for this capability to:
+-- https://github.com/udalov/kotlin-vim (recommended)
+-- Note that there is no LICENSE specified yet.
+
+-- For faster startup, you can setup caching by specifying a storagePath
+-- in the init_options. The default is your home directory.
+return {
+  filetypes = { 'kotlin' },
+  root_markers = root_files,
+  cmd = { bin_name }, -- kotlin-language-server
+  init_options = {
+    -- Enables caching and use project root to store cache data.
+    storagePath = util.root_pattern(unpack(root_files))(vim.fn.expand '%:p:h'),
+  },
+}