fix(lsp): only disable inlay hints / diagnostics if no other clients are connected (#24535)

This fixes the issue where the LspNotify handlers for inlay_hint /
diagnostics would end up refreshing all attached clients.

The handler would call util._refresh, which called
vim.lsp.buf_request, which calls the method on all attached clients.

Now util._refresh takes an optional client_id parameter, which is used
to specify a specific client to update.

This commit also fixes util._refresh's handling of the `only_visible`
flag. Previously if `only_visible` was false, two requests would be made
to the server: one for the visible region, and one for the entire file.

Co-authored-by: Stanislav Asunkin <1353637+stasjok@users.noreply.github.com>
Co-authored-by: Mathias Fußenegger <mfussenegger@users.noreply.github.com>

2 files changed, 157 insertions, 0 deletions

diff --git a/test/functional/plugin/lsp/diagnostic_spec.lua b/test/functional/plugin/lsp/diagnostic_spec.lua
index d1c3fd6b1e..1da0222114 100644
--- a/test/functional/plugin/lsp/diagnostic_spec.lua
+++ b/test/functional/plugin/lsp/diagnostic_spec.lua
@@ -84,6 +84,7 @@ describe('vim.lsp.diagnostic', function()
       local lines = {"1st line of text", "2nd line of text", "wow", "cool", "more", "lines"}
       vim.fn.bufload(diagnostic_bufnr)
       vim.api.nvim_buf_set_lines(diagnostic_bufnr, 0, 1, false, lines)
+      vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
       return diagnostic_bufnr
     ]], fake_uri)
   end)
@@ -360,5 +361,63 @@ describe('vim.lsp.diagnostic', function()
       eq(2, #extmarks)
       eq(expected_spacing, #extmarks[1][4].virt_text[1][1])
     end)
+
+    it('clears diagnostics when client detaches', function()
+      exec_lua([[
+        vim.lsp.diagnostic.on_diagnostic(nil,
+          {
+            kind = 'full',
+            items = {
+              make_error('Pull Diagnostic', 4, 4, 4, 4),
+            }
+          },
+          {
+            params = {
+              textDocument = { uri = fake_uri },
+            },
+            uri = fake_uri,
+            client_id = client_id,
+          },
+          {}
+        )
+      ]])
+      local diags = exec_lua([[return vim.diagnostic.get(diagnostic_bufnr)]])
+      eq(1, #diags)
+
+      exec_lua([[ vim.lsp.stop_client(client_id) ]])
+
+      diags = exec_lua([[return vim.diagnostic.get(diagnostic_bufnr)]])
+      eq(0, #diags)
+    end)
+
+    it('keeps diagnostics when one client detaches and others still are attached', function()
+      exec_lua([[
+        client_id2 = vim.lsp.start({ name = 'dummy2', cmd = server.cmd })
+
+        vim.lsp.diagnostic.on_diagnostic(nil,
+          {
+            kind = 'full',
+            items = {
+              make_error('Pull Diagnostic', 4, 4, 4, 4),
+            }
+          },
+          {
+            params = {
+              textDocument = { uri = fake_uri },
+            },
+            uri = fake_uri,
+            client_id = client_id,
+          },
+          {}
+        )
+      ]])
+      local diags = exec_lua([[return vim.diagnostic.get(diagnostic_bufnr)]])
+      eq(1, #diags)
+
+      exec_lua([[ vim.lsp.stop_client(client_id2) ]])
+
+      diags = exec_lua([[return vim.diagnostic.get(diagnostic_bufnr)]])
+      eq(1, #diags)
+    end)
   end)
 end)
diff --git a/test/functional/plugin/lsp/inlay_hint_spec.lua b/test/functional/plugin/lsp/inlay_hint_spec.lua
index b19f2ba146..eec86fdb8e 100644
--- a/test/functional/plugin/lsp/inlay_hint_spec.lua
+++ b/test/functional/plugin/lsp/inlay_hint_spec.lua
@@ -135,5 +135,103 @@ describe('inlay hints', function()
           unchanged = true
         })
       end)
+
+    it(
+      'inlay hints are cleared when the client detaches',
+      function()
+        exec_lua([[
+          bufnr = vim.api.nvim_get_current_buf()
+          vim.api.nvim_win_set_buf(0, bufnr)
+          client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
+        ]])
+
+        insert(text)
+        exec_lua([[vim.lsp.inlay_hint(bufnr, true)]])
+        screen:expect({
+          grid = [[
+  auto add(int a, int b)-> int { return a + b; }    |
+                                                    |
+  int main() {                                      |
+      int x = 1;                                    |
+      int y = 2;                                    |
+      return add(a: x,b: y);                        |
+  }                                                 |
+  ^}                                                 |
+                                                    |
+]]
+        })
+        exec_lua([[vim.lsp.stop_client(client_id)]])
+        screen:expect({
+          grid = [[
+  auto add(int a, int b) { return a + b; }          |
+                                                    |
+  int main() {                                      |
+      int x = 1;                                    |
+      int y = 2;                                    |
+      return add(x,y);                              |
+  }                                                 |
+  ^}                                                 |
+                                                    |
+]],
+          unchanged = true
+        })
+      end)
+
+    it(
+      'inlay hints are not cleared when one of several clients detaches',
+      function()
+        -- Start two clients
+        exec_lua([[
+          bufnr = vim.api.nvim_get_current_buf()
+          vim.api.nvim_win_set_buf(0, bufnr)
+          server2 = _create_server({
+            capabilities = {
+              inlayHintProvider = true,
+            },
+            handlers = {
+              ['textDocument/inlayHint'] = function()
+                return {}
+              end,
+            }
+          })
+          client1 = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
+          client2 = vim.lsp.start({ name = 'dummy2', cmd = server2.cmd })
+        ]])
+
+        insert(text)
+        exec_lua([[vim.lsp.inlay_hint(bufnr, true)]])
+        screen:expect({
+          grid = [[
+  auto add(int a, int b)-> int { return a + b; }    |
+                                                    |
+  int main() {                                      |
+      int x = 1;                                    |
+      int y = 2;                                    |
+      return add(a: x,b: y);                        |
+  }                                                 |
+  ^}                                                 |
+                                                    |
+]]
+        })
+
+        -- Now stop one client
+        exec_lua([[ vim.lsp.stop_client(client2) ]])
+
+        -- We should still see the hints
+        screen:expect({
+          grid = [[
+  auto add(int a, int b)-> int { return a + b; }    |
+                                                    |
+  int main() {                                      |
+      int x = 1;                                    |
+      int y = 2;                                    |
+      return add(a: x,b: y);                        |
+  }                                                 |
+  ^}                                                 |
+                                                    |
+]],
+          unchanged = true
+        })
+      end)
   end)
 end)