From e8b3bb6c819317a03d48cff4e367f978ce86dc4c Mon Sep 17 00:00:00 2001
From: Marc Jakobi <marc.jakobi@tiko.energy>
Date: Mon, 23 Oct 2023 00:15:41 +0200
Subject: [PATCH] fix(lsp): compatibility with Neovim 0.9

---
 CHANGELOG.md                       |  2 +-
 lua/rustaceanvim/compat.lua        | 12 ++++++++++++
 lua/rustaceanvim/lsp.lua           | 23 ++++++-----------------
 lua/rustaceanvim/rust_analyzer.lua | 18 ++++++++++++++++--
 nix/ci-overlay.nix                 |  5 ++++-
 spec/lsp_spec.lua                  | 13 +++++++++++--
 6 files changed, 50 insertions(+), 23 deletions(-)
 create mode 100644 lua/rustaceanvim/compat.lua

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d234fd9..144cc985 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,7 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - Add support for `workspace/didChangeWorkspaceFolders` to prevent more than one
   rust-analyzer server from spawning per Neovim instance [#7](https://github.com/mrcjkb/rustaceanvim/issues/7).
-- Implement `vim.fs.joinpath` for Neovim 0.9 compatibility.
+- Neovim 0.9 compatibility [#9](https://github.com/mrcjkb/rustaceanvim/issues/9).
 
 ## [3.0.0] - 2023-10-22
 
diff --git a/lua/rustaceanvim/compat.lua b/lua/rustaceanvim/compat.lua
new file mode 100644
index 00000000..ac00b207
--- /dev/null
+++ b/lua/rustaceanvim/compat.lua
@@ -0,0 +1,12 @@
+---@diagnostic disable: deprecated
+---@mod rustaceanvim.compat Functions for backward compatibility with older Neovim versions
+
+local M = {}
+
+M.joinpath = vim.fs.joinpath or function(...)
+  return (table.concat({ ... }, '/'):gsub('//+', '/'))
+end
+
+M.get_clients = vim.lsp.get_clients or vim.lsp.get_active_clients
+
+return M
diff --git a/lua/rustaceanvim/lsp.lua b/lua/rustaceanvim/lsp.lua
index f1e97aee..a45f8cb4 100644
--- a/lua/rustaceanvim/lsp.lua
+++ b/lua/rustaceanvim/lsp.lua
@@ -2,10 +2,9 @@ local M = {}
 ---@type RustaceanConfig
 local config = require('rustaceanvim.config.internal')
 local methods = require('vim.lsp.protocol').Methods
-
-local joinpath = vim.fs.joinpath or function(...)
-  return (table.concat({ ... }, '/'):gsub('//+', '/'))
-end
+local compat = require('rustaceanvim.compat')
+local rust_analyzer = require('rustaceanvim.rust_analyzer')
+local joinpath = compat.joinpath
 
 local function override_apply_text_edits()
   local old_func = vim.lsp.util.apply_text_edits
@@ -26,7 +25,7 @@ local function is_library(fname)
 
   for _, item in ipairs { toolchains, registry } do
     if fname:sub(1, #item) == item then
-      local clients = vim.lsp.get_clients { name = 'rust-analyzer' }
+      local clients = rust_analyzer.get_active_rustaceanvim_clients()
       return clients[#clients].config.root_dir
     end
   end
@@ -75,16 +74,6 @@ local function get_root_dir(fname)
     })[1])
 end
 
----@param bufnr? number
----@return lsp.Client[]
-local function get_active_rustaceanvim_clients(bufnr)
-  local filter = { name = 'rust-analyzer' }
-  if bufnr then
-    filter.bufnr = bufnr
-  end
-  return vim.lsp.get_clients(filter)
-end
-
 local function is_in_workspace(client, root_dir)
   if not client.workspace_folders then
     return false
@@ -109,7 +98,7 @@ M.start = function()
   lsp_start_opts.root_dir = root_dir
 
   -- Check if a client is already running and add the workspace folder if necessary.
-  for _, client in pairs(get_active_rustaceanvim_clients()) do
+  for _, client in pairs(rust_analyzer.get_active_rustaceanvim_clients()) do
     if not is_in_workspace(client, root_dir) then
       local workspace_folder = { uri = vim.uri_from_fname(root_dir), name = root_dir }
       local params = {
@@ -220,7 +209,7 @@ end
 ---@return table[] clients A list of clients that will be stopped
 M.stop = function()
   local bufnr = vim.api.nvim_get_current_buf()
-  local clients = get_active_rustaceanvim_clients(bufnr)
+  local clients = rust_analyzer.get_active_rustaceanvim_clients(bufnr)
   vim.lsp.stop_client(clients)
   return clients
 end
diff --git a/lua/rustaceanvim/rust_analyzer.lua b/lua/rustaceanvim/rust_analyzer.lua
index 181b1c2f..c0198cfc 100644
--- a/lua/rustaceanvim/rust_analyzer.lua
+++ b/lua/rustaceanvim/rust_analyzer.lua
@@ -1,6 +1,20 @@
+---@mod rustaceanvim.rust_analyzer Functions for interacting with rust-analyzer
+
+local compat = require('rustaceanvim.compat')
+
 ---@class RustAnalyzerClientAdapter
 local M = {}
 
+---@param bufnr? number
+---@return lsp.Client[]
+M.get_active_rustaceanvim_clients = function(bufnr)
+  local filter = { name = 'rust-analyzer' }
+  if bufnr then
+    filter.bufnr = bufnr
+  end
+  return compat.get_clients(filter)
+end
+
 ---@param bufnr integer Buffer handle, or 0 for current.
 ---@param method string LSP method name
 ---@param params table|nil Parameters to send to the server
@@ -10,7 +24,7 @@ M.buf_request = function(bufnr, method, params, handler)
   if bufnr == nil or bufnr == 0 then
     bufnr = vim.api.nvim_get_current_buf()
   end
-  for _, client in ipairs(vim.lsp.get_clients { name = 'rust-analyzer' }) do
+  for _, client in ipairs(M.get_active_rustaceanvim_clients()) do
     if client.supports_method(method, { bufnr = bufnr }) then
       client.request(method, params, handler, bufnr)
     end
@@ -20,7 +34,7 @@ end
 ---@param method string LSP method name
 ---@param params table|nil Parameters to send to the server
 M.notify = function(method, params)
-  for _, client in ipairs(vim.lsp.get_clients { name = 'rust-analyzer' }) do
+  for _, client in ipairs(M.get_active_rustaceanvim_clients()) do
     if client.supports_method(method) then
       client.notify(method, params)
     end
diff --git a/nix/ci-overlay.nix b/nix/ci-overlay.nix
index 33e7dbf3..aea1e787 100755
--- a/nix/ci-overlay.nix
+++ b/nix/ci-overlay.nix
@@ -33,7 +33,10 @@
       neovim = nvim-wrapped;
 
       # luaPackages = ps: with ps; [];
-      # extraPackages = [];
+      extraPackages = with final; [
+        rust-analyzer
+        cargo
+      ];
 
       preCheck = ''
         export HOME=$(realpath .)
diff --git a/spec/lsp_spec.lua b/spec/lsp_spec.lua
index 65b6b6c4..2ecbfd69 100644
--- a/spec/lsp_spec.lua
+++ b/spec/lsp_spec.lua
@@ -1,11 +1,20 @@
+local uv = vim.uv or vim.loop
+-- load RustAnalyzer command
+require('rustaceanvim.lsp')
+
+local stub = require('luassert.stub')
 describe('LSP client API', function()
   local RustaceanConfig = require('rustaceanvim.config.internal')
   local Types = require('rustaceanvim.types.internal')
   local ra_bin = Types.evaluate(RustaceanConfig.server.cmd)[1]
   if vim.fn.executable(ra_bin) ~= 0 then
     it('Can spin up rust-analyzer.', function()
-      --- TODO: Figure out how to add tests for this
-      print('TODO')
+      local lsp_start = stub(vim.lsp, 'start')
+      vim.cmd.e('test.rs')
+      vim.cmd.RustAnalyzer('start')
+      -- TODO: Use something less flaky, e.g. a timeout
+      uv.sleep(5000)
+      assert.stub(lsp_start).was_called()
     end)
   end
 end)