feat(lsp): support refreshing workspace diagnostics

runtime/lua/vim/lsp/diagnostic.lua

@@ -395,9 +395,17 @@ function M.on_refresh(err, _, ctx)
   if err then
     return vim.NIL
   end
-  for bufnr in pairs(vim.lsp.get_client_by_id(ctx.client_id).attached_buffers or {}) do
-    if bufstates[bufnr] and bufstates[bufnr].pull_kind == 'document' then
-      refresh(bufnr)
+  local client = vim.lsp.get_client_by_id(ctx.client_id)
+  if
+    client.server_capabilities.diagnosticProvider
+    and client.server_capabilities.diagnosticProvider.workspaceDiagnostics
+  then
+    M._workspace_diagnostics(ctx)
+  else
+    for bufnr in pairs(client.attached_buffers or {}) do
+      if bufstates[bufnr] and bufstates[bufnr].pull_kind == 'document' then
+        refresh(bufnr)
+      end
     end
   end
 

test/functional/plugin/lsp/diagnostic_spec.lua

@@ -673,5 +673,52 @@ describe('vim.lsp.diagnostic', function()
       eq(1, #diags)
       eq(2, diags[1].severity)
     end)
+
+    it('refreshes workspace diagnostics', function()
+      local fake_uri_3 = 'file:///fake/uri3'
+      exec_lua(create_server_definition)
+      exec_lua(function()
+        _G.requests = 0
+        _G.server = _G._create_server({
+          capabilities = {
+            diagnosticProvider = { workspaceDiagnostics = true },
+          },
+          handlers = {
+            ['workspace/diagnostic'] = function(_, _, callback)
+              _G.requests = _G.requests + 1
+              callback(nil, {
+                items = {
+                  {
+                    kind = 'full',
+                    uri = fake_uri_3,
+                    items = {
+                      _G.make_error('Workspace Diagnostic', 4, 4, 4, 4),
+                    },
+                  },
+                },
+              })
+            end,
+          },
+        })
+        client_id = vim.lsp.start({ name = 'dummy', cmd = _G.server.cmd })
+      end)
+
+      local diags = exec_lua(function()
+        return vim.diagnostic.get()
+      end)
+      eq(0, #diags)
+
+      local requests, diags = exec_lua(function()
+        vim.lsp.diagnostic.on_refresh(nil, nil, {
+          method = 'workspace/diagnostic/refresh',
+          client_id = client_id,
+        })
+
+        return _G.requests, vim.diagnostic.get()
+      end)
+      eq(1, requests)
+      eq(1, #diags)
+      eq(1, diags[1].severity)
+    end)
   end)
 end)