feat(lsp): move inlay_hint() to vim.lsp (#24130)

Allows to keep more functions hidden and gives a path forward for
further inlay_hint related functions - like applying textEdits.

See https://github.com/neovim/neovim/pull/23984#pullrequestreview-1486624668

7 files changed, 60 insertions, 53 deletions

diff --git a/runtime/doc/lsp.txt b/runtime/doc/lsp.txt
index 42600e405c..95cbd211bf 100644
--- a/runtime/doc/lsp.txt
+++ b/runtime/doc/lsp.txt
@@ -810,6 +810,13 @@ get_log_path()                                        *vim.lsp.get_log_path()*
     Return: ~
         (string) path to log file
 
+inlay_hint({bufnr}, {enable})                           *vim.lsp.inlay_hint()*
+    Enable/disable/toggle inlay hints for a buffer
+
+    Parameters: ~
+      • {bufnr}   (integer) Buffer handle, or 0 for current
+      • {enable}  (boolean|nil) true/false to enable/disable, nil to toggle
+
 omnifunc({findstart}, {base})                             *vim.lsp.omnifunc()*
     Implements 'omnifunc' compatible LSP completion.
 
@@ -1227,13 +1234,6 @@ incoming_calls()                                *vim.lsp.buf.incoming_calls()*
     window. If the symbol can resolve to multiple items, the user can pick one
     in the |inputlist()|.
 
-inlay_hint({bufnr}, {enable})                       *vim.lsp.buf.inlay_hint()*
-    Enable/disable/toggle inlay hints for a buffer
-
-    Parameters: ~
-      • {bufnr}   (integer) Buffer handle, or 0 for current
-      • {enable}  (boolean|nil) true/false to enable/disable, nil to toggle
-
 list_workspace_folders()                *vim.lsp.buf.list_workspace_folders()*
     List workspace folders.
 
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 153441b0a5..0a9b926b7f 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -98,7 +98,7 @@ The following new APIs and features were added.
 
 • |nvim_set_keymap()| and |nvim_del_keymap()| now support abbreviations.
 
-• Implemented LSP inlay hints: |vim.lsp.buf.inlay_hint()|
+• Implemented LSP inlay hints: |vim.lsp.inlay_hint()|
   https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_inlayHint
 
 ==============================================================================
diff --git a/runtime/lua/vim/lsp.lua b/runtime/lua/vim/lsp.lua
index 1e5ce8fa10..ca4851f8d7 100644
--- a/runtime/lua/vim/lsp.lua
+++ b/runtime/lua/vim/lsp.lua
@@ -2474,6 +2474,13 @@ function lsp.with(handler, override_config)
   end
 end
 
+--- Enable/disable/toggle inlay hints for a buffer
+---@param bufnr (integer) Buffer handle, or 0 for current
+---@param enable (boolean|nil) true/false to enable/disable, nil to toggle
+function lsp.inlay_hint(bufnr, enable)
+  return require('vim.lsp.inlay_hint')(bufnr, enable)
+end
+
 --- Helper function to use when implementing a handler.
 --- This will check that all of the keys in the user configuration
 --- are valid keys and make sense to include for this handler.
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index c2e0179cc4..0369725216 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -796,19 +796,4 @@ function M.execute_command(command_params)
   request('workspace/executeCommand', command_params)
 end
 
---- Enable/disable/toggle inlay hints for a buffer
----@param bufnr (integer) Buffer handle, or 0 for current
----@param enable (boolean|nil) true/false to enable/disable, nil to toggle
-function M.inlay_hint(bufnr, enable)
-  vim.validate({ enable = { enable, { 'boolean', 'nil' } }, bufnr = { bufnr, 'number' } })
-  local inlay_hint = require('vim.lsp._inlay_hint')
-  if enable then
-    inlay_hint.enable(bufnr)
-  elseif enable == false then
-    inlay_hint.disable(bufnr)
-  else
-    inlay_hint.toggle(bufnr)
-  end
-end
-
 return M
diff --git a/runtime/lua/vim/lsp/handlers.lua b/runtime/lua/vim/lsp/handlers.lua
index 284e3ef2d0..625a2ed282 100644
--- a/runtime/lua/vim/lsp/handlers.lua
+++ b/runtime/lua/vim/lsp/handlers.lua
@@ -220,7 +220,7 @@ M['textDocument/codeLens'] = function(...)
 end
 
 M['textDocument/inlayHint'] = function(...)
-  return require('vim.lsp._inlay_hint').on_inlayhint(...)
+  return require('vim.lsp.inlay_hint').on_inlayhint(...)
 end
 
 --see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_references
@@ -617,22 +617,8 @@ M['window/showDocument'] = function(_, result, ctx, _)
 end
 
 ---@see https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_inlayHint_refresh
-M['workspace/inlayHint/refresh'] = function(err, _, ctx)
-  local inlay_hint = require('vim.lsp._inlay_hint')
-  if err then
-    return vim.NIL
-  end
-
-  for _, bufnr in ipairs(vim.lsp.get_buffers_by_client_id(ctx.client_id)) do
-    for _, winid in ipairs(api.nvim_list_wins()) do
-      if api.nvim_win_get_buf(winid) == bufnr then
-        inlay_hint.refresh({ bufnr = bufnr })
-        break
-      end
-    end
-  end
-
-  return vim.NIL
+M['workspace/inlayHint/refresh'] = function(err, result, ctx, config)
+  return require('vim.lsp.inlay_hint').on_refresh(err, result, ctx, config)
 end
 
 -- Add boilerplate error validation and logging for all of these.
diff --git a/runtime/lua/vim/lsp/_inlay_hint.lua b/runtime/lua/vim/lsp/inlay_hint.lua
index ccf1b5cca4..1af18bbc61 100644
--- a/runtime/lua/vim/lsp/_inlay_hint.lua
+++ b/runtime/lua/vim/lsp/inlay_hint.lua
@@ -101,7 +101,7 @@ end
 ---  - only_visible (boolean, default: false): Whether to only refresh hints for the visible regions of the buffer
 ---
 ---@private
-function M.refresh(opts)
+local function refresh(opts)
   opts = opts or {}
   local bufnr = resolve_bufnr(opts.bufnr or 0)
   local bufstate = bufstates[bufnr]
@@ -139,6 +139,24 @@ function M.refresh(opts)
   end
 end
 
+--- |lsp-handler| for the method `textDocument/inlayHint/refresh`
+---@private
+function M.on_refresh(err, _, ctx, _)
+  if err then
+    return vim.NIL
+  end
+  for _, bufnr in ipairs(vim.lsp.get_buffers_by_client_id(ctx.client_id)) do
+    for _, winid in ipairs(api.nvim_list_wins()) do
+      if api.nvim_win_get_buf(winid) == bufnr then
+        refresh({ bufnr = bufnr })
+        break
+      end
+    end
+  end
+
+  return vim.NIL
+end
+
 --- Clear inlay hints
 ---@param bufnr (integer) Buffer handle, or 0 for current
 ---@private
@@ -163,18 +181,18 @@ end
 ---@private
 local function make_request(request_bufnr)
   reset_timer(request_bufnr)
-  M.refresh({ bufnr = request_bufnr })
+  refresh({ bufnr = request_bufnr })
 end
 
 --- Enable inlay hints for a buffer
 ---@param bufnr (integer) Buffer handle, or 0 for current
 ---@private
-function M.enable(bufnr)
+local function enable(bufnr)
   bufnr = resolve_bufnr(bufnr)
   local bufstate = bufstates[bufnr]
   if not (bufstate and bufstate.enabled) then
     bufstates[bufnr] = { enabled = true, timer = nil, applied = {} }
-    M.refresh({ bufnr = bufnr })
+    refresh({ bufnr = bufnr })
     api.nvim_buf_attach(bufnr, true, {
       on_lines = function(_, cb_bufnr)
         if not bufstates[cb_bufnr].enabled then
@@ -190,7 +208,7 @@ function M.enable(bufnr)
         if bufstates[cb_bufnr] and bufstates[cb_bufnr].enabled then
           bufstates[cb_bufnr] = { enabled = true, applied = {} }
         end
-        M.refresh({ bufnr = cb_bufnr })
+        refresh({ bufnr = cb_bufnr })
       end,
       on_detach = function(_, cb_bufnr)
         clear(cb_bufnr)
@@ -211,7 +229,7 @@ end
 --- Disable inlay hints for a buffer
 ---@param bufnr (integer) Buffer handle, or 0 for current
 ---@private
-function M.disable(bufnr)
+local function disable(bufnr)
   bufnr = resolve_bufnr(bufnr)
   if bufstates[bufnr] and bufstates[bufnr].enabled then
     clear(bufnr)
@@ -223,7 +241,7 @@ end
 --- Toggle inlay hints for a buffer
 ---@param bufnr (integer) Buffer handle, or 0 for current
 ---@private
-function M.toggle(bufnr)
+local function toggle(bufnr)
   bufnr = resolve_bufnr(bufnr)
   local bufstate = bufstates[bufnr]
   if bufstate and bufstate.enabled then
@@ -281,4 +299,15 @@ api.nvim_set_decoration_provider(namespace, {
   end,
 })
 
-return M
+return setmetatable(M, {
+  __call = function(_, bufnr, enable_)
+    vim.validate({ enable = { enable_, { 'boolean', 'nil' } }, bufnr = { bufnr, 'number' } })
+    if enable_ then
+      enable(bufnr)
+    elseif enable_ == false then
+      disable(bufnr)
+    else
+      toggle(bufnr)
+    end
+  end,
+})
diff --git a/test/functional/plugin/lsp/inlay_hint_spec.lua b/test/functional/plugin/lsp/inlay_hint_spec.lua
index 574a4fa5a0..b19f2ba146 100644
--- a/test/functional/plugin/lsp/inlay_hint_spec.lua
+++ b/test/functional/plugin/lsp/inlay_hint_spec.lua
@@ -64,7 +64,7 @@ describe('inlay hints', function()
     end)
 
     it(
-      'inlay hints are applied when vim.lsp.buf.inlay_hint(true) is called',
+      'inlay hints are applied when vim.lsp.inlay_hint(true) is called',
       function()
         local res = exec_lua([[
           bufnr = vim.api.nvim_get_current_buf()
@@ -79,7 +79,7 @@ describe('inlay hints', function()
 
 
         insert(text)
-        exec_lua([[vim.lsp.buf.inlay_hint(bufnr, true)]])
+        exec_lua([[vim.lsp.inlay_hint(bufnr, true)]])
         screen:expect({
           grid = [[
   auto add(int a, int b)-> int { return a + b; }    |
@@ -96,7 +96,7 @@ describe('inlay hints', function()
       end)
 
     it(
-      'inlay hints are cleared when vim.lsp.buf.inlay_hint(false) is called',
+      'inlay hints are cleared when vim.lsp.inlay_hint(false) is called',
       function()
         exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
@@ -105,7 +105,7 @@ describe('inlay hints', function()
       ]])
 
         insert(text)
-        exec_lua([[vim.lsp.buf.inlay_hint(bufnr, true)]])
+        exec_lua([[vim.lsp.inlay_hint(bufnr, true)]])
         screen:expect({
           grid = [[
   auto add(int a, int b)-> int { return a + b; }    |
@@ -119,7 +119,7 @@ describe('inlay hints', function()
                                                     |
 ]]
         })
-        exec_lua([[vim.lsp.buf.inlay_hint(bufnr, false)]])
+        exec_lua([[vim.lsp.inlay_hint(bufnr, false)]])
         screen:expect({
           grid = [[
   auto add(int a, int b) { return a + b; }          |