2 files changed, 84 insertions, 0 deletions
diff --git a/test/functional/fixtures/fake-lsp-server.lua b/test/functional/fixtures/fake-lsp-server.lua
index dca7f35923..a30eb748d0 100644
--- a/test/functional/fixtures/fake-lsp-server.lua
+++ b/test/functional/fixtures/fake-lsp-server.lua
@@ -125,6 +125,26 @@ function tests.basic_check_capabilities()
   }
 end
 
+function tests.capabilities_for_client_supports_method()
+  skeleton {
+    on_init = function(params)
+      local expected_capabilities = protocol.make_client_capabilities()
+      assert_eq(params.capabilities, expected_capabilities)
+      return {
+        capabilities = {
+          textDocumentSync = protocol.TextDocumentSyncKind.Full;
+          completionProvider = true;
+          hoverProvider = true;
+          definitionProvider = false;
+          referencesProvider = false;
+        }
+      }
+    end;
+    body = function()
+    end;
+  }
+end
+
 function tests.basic_finish()
   skeleton {
     on_init = function(params)
diff --git a/test/functional/plugin/lsp_spec.lua b/test/functional/plugin/lsp_spec.lua
index f07a2d18a2..067a13ce68 100644
--- a/test/functional/plugin/lsp_spec.lua
+++ b/test/functional/plugin/lsp_spec.lua
@@ -270,6 +270,70 @@ describe('LSP', function()
         test_name = "basic_check_capabilities";
         on_init = function(client)
           client.stop()
+          local full_kind = exec_lua("return require'vim.lsp.protocol'.TextDocumentSyncKind.Full")
+          eq(full_kind, client.resolved_capabilities().text_document_did_change)
+        end;
+        on_exit = function(code, signal)
+          eq(0, code, "exit code", fake_lsp_logfile)
+          eq(0, signal, "exit signal", fake_lsp_logfile)
+        end;
+        on_callback = function(...)
+          eq(table.remove(expected_callbacks), {...}, "expected callback")
+        end;
+      }
+    end)
+
+    it('client.supports_methods() should validate capabilities', function()
+      local expected_callbacks = {
+        {NIL, "shutdown", {}, 1};
+      }
+      test_rpc_server {
+        test_name = "capabilities_for_client_supports_method";
+        on_init = function(client)
+          client.stop()
+          local full_kind = exec_lua("return require'vim.lsp.protocol'.TextDocumentSyncKind.Full")
+          eq(full_kind, client.resolved_capabilities().text_document_did_change)
+          eq(true, client.resolved_capabilities().completion)
+          eq(true, client.resolved_capabilities().hover)
+          eq(false, client.resolved_capabilities().goto_definition)
+          eq(false, client.resolved_capabilities().rename)
+
+          -- known methods for resolved capabilities
+          eq(true, client.supports_method("textDocument/hover"))
+          eq(false, client.supports_method("textDocument/definition"))
+
+          -- unknown methods are assumed to be supported.
+          eq(true, client.supports_method("unknown-method"))
+        end;
+        on_exit = function(code, signal)
+          eq(0, code, "exit code", fake_lsp_logfile)
+          eq(0, signal, "exit signal", fake_lsp_logfile)
+        end;
+        on_callback = function(...)
+          eq(table.remove(expected_callbacks), {...}, "expected callback")
+        end;
+      }
+    end)
+
+    it('should call unsupported_method when trying to call an unsupported method', function()
+      local expected_callbacks = {
+        {NIL, "shutdown", {}, 1};
+      }
+      test_rpc_server {
+        test_name = "capabilities_for_client_supports_method";
+        on_setup = function()
+            exec_lua([=[
+              vim.lsp._unsupported_method = function(method)
+                vim.lsp._last_unsupported_method = method
+                return 'fake-error'
+              end
+              vim.lsp.buf.hover()
+            ]=])
+        end;
+        on_init = function(client)
+          client.stop()
+          local method = exec_lua("return vim.lsp._last_unsupported_method")
+          eq("textDocument/hover", method)
         end;
         on_exit = function(code, signal)
           eq(0, code, "exit code", fake_lsp_logfile)