fix: add compat shim for handler change in core (#1248)

Add a compatibility shim to `util.lua` adapting to change in handler signature
and use it where needed.

(Skip `rust-analyzer` and `denols` since their requests don't use handlers.)

4 files changed, 62 insertions, 48 deletions

diff --git a/lua/lspconfig/clangd.lua b/lua/lspconfig/clangd.lua
index 22c89e52..e8876af6 100644
--- a/lua/lspconfig/clangd.lua
+++ b/lua/lspconfig/clangd.lua
@@ -5,16 +5,21 @@ local util = require 'lspconfig/util'
 local function switch_source_header(bufnr)
   bufnr = util.validate_bufnr(bufnr)
   local params = { uri = vim.uri_from_bufnr(bufnr) }
-  vim.lsp.buf_request(bufnr, 'textDocument/switchSourceHeader', params, function(err, _, result)
-    if err then
-      error(tostring(err))
-    end
-    if not result then
-      print 'Corresponding file cannot be determined'
-      return
-    end
-    vim.api.nvim_command('edit ' .. vim.uri_to_fname(result))
-  end)
+  vim.lsp.buf_request(
+    bufnr,
+    'textDocument/switchSourceHeader',
+    params,
+    util.compat_handler(function(err, result)
+      if err then
+        error(tostring(err))
+      end
+      if not result then
+        print 'Corresponding file cannot be determined'
+        return
+      end
+      vim.api.nvim_command('edit ' .. vim.uri_to_fname(result))
+    end)
+  )
 end
 
 local root_pattern = util.root_pattern('compile_commands.json', 'compile_flags.txt', '.git')
diff --git a/lua/lspconfig/rust_analyzer.lua b/lua/lspconfig/rust_analyzer.lua
index 1f47dc2b..bbe86b3d 100644
--- a/lua/lspconfig/rust_analyzer.lua
+++ b/lua/lspconfig/rust_analyzer.lua
@@ -1,10 +1,9 @@
 local configs = require 'lspconfig/configs'
 local util = require 'lspconfig/util'
-local lsp = vim.lsp
 
 local function reload_workspace(bufnr)
   bufnr = util.validate_bufnr(bufnr)
-  lsp.buf_request(bufnr, 'rust-analyzer/reloadWorkspace', nil, function(err, _, result, _)
+  vim.lsp.buf_request(bufnr, 'rust-analyzer/reloadWorkspace', nil, function(err)
     if err then
       error(tostring(err))
     end
diff --git a/lua/lspconfig/texlab.lua b/lua/lspconfig/texlab.lua
index f1e21ea3..232773bc 100644
--- a/lua/lspconfig/texlab.lua
+++ b/lua/lspconfig/texlab.lua
@@ -16,38 +16,22 @@ local texlab_forward_status = vim.tbl_add_reverse_lookup {
   Unconfigured = 3,
 }
 
--- add compatibility shim for breaking signature change
-local function mk_handler(fn)
-  return function(...)
-    local config_or_client_id = select(4, ...)
-    local is_new = type(config_or_client_id) ~= 'number'
-    if is_new then
-      return fn(...)
-    else
-      local err = select(1, ...)
-      local method = select(2, ...)
-      local result = select(3, ...)
-      local client_id = select(4, ...)
-      local bufnr = select(5, ...)
-      local config = select(6, ...)
-      return fn(err, result, { method = method, client_id = client_id, bufnr = bufnr }, config)
-    end
-  end
-end
-
-local function request(bufnr, method, params, handler)
-  return lsp.buf_request(bufnr, method, params, mk_handler(handler))
-end
-
 local function buf_build(bufnr)
   bufnr = util.validate_bufnr(bufnr)
-  local params = { textDocument = { uri = vim.uri_from_bufnr(bufnr) } }
-  request(bufnr, 'textDocument/build', params, function(err, result, _)
-    if err then
-      error(tostring(err))
-    end
-    print('Build ' .. texlab_build_status[result.status])
-  end)
+  local params = {
+    textDocument = { uri = vim.uri_from_bufnr(bufnr) },
+  }
+  lsp.buf_request(
+    bufnr,
+    'textDocument/build',
+    params,
+    util.compat_handler(function(err, result)
+      if err then
+        error(tostring(err))
+      end
+      print('Build ' .. texlab_build_status[result.status])
+    end)
+  )
 end
 
 local function buf_search(bufnr)
@@ -56,12 +40,17 @@ local function buf_search(bufnr)
     textDocument = { uri = vim.uri_from_bufnr(bufnr) },
     position = { line = vim.fn.line '.' - 1, character = vim.fn.col '.' },
   }
-  request(bufnr, 'textDocument/forwardSearch', params, function(err, result, _)
-    if err then
-      error(tostring(err))
-    end
-    print('Search ' .. texlab_forward_status[result.status])
-  end)
+  lsp.buf_request(
+    bufnr,
+    'textDocument/forwardSearch',
+    params,
+    util.compat_handler(function(err, result)
+      if err then
+        error(tostring(err))
+      end
+      print('Search ' .. texlab_forward_status[result.status])
+    end)
+  )
 end
 
 -- bufnr isn't actually required here, but we need a valid buffer in order to
diff --git a/lua/lspconfig/util.lua b/lua/lspconfig/util.lua
index 50791462..6e0f7f41 100644
--- a/lua/lspconfig/util.lua
+++ b/lua/lspconfig/util.lua
@@ -19,6 +19,27 @@ M.default_config = {
 -- global on_setup hook
 M.on_setup = nil
 
+-- add compatibility shim for breaking signature change
+-- from https://github.com/mfussenegger/nvim-lsp-compl/
+-- TODO: remove after Neovim release
+function M.compat_handler(handler)
+  return function(...)
+    local config_or_client_id = select(4, ...)
+    local is_new = type(config_or_client_id) ~= 'number'
+    if is_new then
+      return handler(...)
+    else
+      local err = select(1, ...)
+      local method = select(2, ...)
+      local result = select(3, ...)
+      local client_id = select(4, ...)
+      local bufnr = select(5, ...)
+      local config = select(6, ...)
+      return handler(err, result, { method = method, client_id = client_id, bufnr = bufnr }, config)
+    end
+  end
+end
+
 function M.validate_bufnr(bufnr)
   validate {
     bufnr = { bufnr, 'n' },