plugin/emacs: add Eglot support

This commit also ignores client notifications that would make
quicklintjs to crash and accept "js" as a language_id for files,
that's what Eglot uses for JavaScript.

Signed-off-by: wagner riffel <[email protected]>

plugin/emacs/CMakeLists.txt

@@ -6,6 +6,7 @@ include(GNUInstallDirs)
 
 install(
   FILES flycheck-quicklintjs.el
+  FILES eglot-quicklintjs.el
   DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/emacs/site-lisp"
 )
 

plugin/emacs/eglot-quicklintjs.el

@@ -0,0 +1,62 @@
+;;; eglot-quicklintjs.el --- Eglot support for quick-lint-js   -*- lexical-binding: t; -*-
+
+;;; Commentary:
+
+;; Eglot support for quick-lint-js.
+
+;; Example usage in your init.el:
+;;
+;; (require 'eglot-quicklintjs)
+;;
+;; (defun my-eglot-quicklintjs-setup ()
+;;   "Configure eglot-quicklintjs for better experience."
+;;
+;;   ;; Remove the time to wait after last change before automatically checking
+;;   ;; buffer.  The default is 0.5 (500ms)
+;;   (setq-local eglot-send-changes-idle-time 0))
+;; (add-hook 'js-mode-hook #'my-eglot-quicklintjs-setup)
+
+;;; Code:
+
+(require 'eglot)
+
+(defgroup eglot-quicklintjs nil
+  "quick-lint-js Eglot integration."
+  :group 'eglot-quicklintjs
+  :link '(url-link :tag "Website" "https://quick-lint-js.com"))
+
+(defcustom eglot-quicklintjs-program "quick-lint-js"
+  "Path to quick-lint-js program to run."
+  :group 'eglot-quicklintjs
+  :type 'stringp)
+
+(defcustom eglot-quicklintjs-args nil
+  "Arguments to quick-lint-js."
+  :group 'eglot-quicklintjs
+  :type '(repeat string))
+
+(add-to-list 'eglot-server-programs `(js-mode . (,eglot-quicklintjs-program
+                                                  "--lsp-server"
+                                                  ,@eglot-quicklintjs-args)))
+
+(provide 'eglot-quicklintjs)
+
+;; quick-lint-js finds bugs in JavaScript programs.
+;; Copyright (C) 2020  Matthew Glazar
+;;
+;; This file is part of quick-lint-js.
+;;
+;; quick-lint-js is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; quick-lint-js is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with quick-lint-js.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; eglot-quicklintjs.el ends here

plugin/emacs/test/quicklintjs-test.el

@@ -9,6 +9,12 @@
                           (expand-file-name default-directory)
                           ".melpa-cache/"))
 
+(defun quicklintjs-install-deps (deps)
+  (mapcar (lambda (pkg) (unless (package-installed-p pkg)
+                          (if (> emacs-major-version 24)
+                              (package-install pkg t)
+                            (package-install pkg)))) deps))
+
 (defun quicklintjs-test-main ()
   (setq package-user-dir cache-dir-name
         package-check-signature nil)
@@ -19,23 +25,27 @@
   (unless package-archive-contents
     (package-refresh-contents))
 
-  (unless (package-installed-p 'flycheck)
-    ;; the DONT-SELECT argument is only available and make sense
-    ;; in emacs 25 and above.
-    (if (> emacs-major-version 24)
-        (package-install 'flycheck t)
-      (package-install 'flycheck)))
+  (quicklintjs-install-deps (if (>= emacs-major-version 26)
+                                '(flycheck eglot)
+                              '(flycheck)))
+  (def-flycheck-tests)
+  (def-eglot-tests)
+  (ert-run-tests-batch-and-exit))
+
+(defun def-eglot-tests ()
+  (when (>= emacs-major-version 26)
+    (require 'eglot-quicklintjs)
+    (ert-deftest quicklintjs-is-in-eglot-servers ()
+      (should (member '(js-mode "quick-lint-js" "--lsp")  eglot-server-programs)))))
 
+(defun def-flycheck-tests ()
   (require 'flycheck)
   (require 'flycheck-ert)
   (require 'flycheck-quicklintjs)
-  (def-flycheck-tests)
-  (ert-run-tests-batch-and-exit))
 
-(ert-deftest quicklintjs-is-in-checkers ()
-  (should (member 'javascript-quicklintjs flycheck-checkers)))
+  (ert-deftest quicklintjs-is-in-flycheck-checkers ()
+    (should (member 'javascript-quicklintjs flycheck-checkers)))
 
-(defun def-flycheck-tests ()
   (flycheck-ert-def-checker-test
    javascript-quicklintjs javascript error
    (let ((flycheck-checker 'javascript-quicklintjs)

src/lsp-server.cpp

@@ -120,6 +120,12 @@ void linting_lsp_server_handler<Linter>::handle_notification(
     std::exit(this->shutdown_requested_ ? 0 : 1);
   } else if (starts_with(method, "$/"sv)) {
     // Do nothing.
+  } else if (method == "workspace/didChangeConfiguration") {
+    // Do nothing.
+  } else if (method == "textDocument/didSave") {
+    // Do nothing.
+  } else if (method == "textDocument/willSave") {
+    // Do nothing.
   } else {
     QLJS_UNIMPLEMENTED();
   }
@@ -266,7 +272,7 @@ void linting_lsp_server_handler<Linter>::
   doc.doc.set_text(make_string_view(text_document["text"]));
   doc.version_json = get_raw_json(version);
 
-  if (language_id == "javascript") {
+  if (language_id == "javascript" || language_id == "js") {
     doc.type = document_type::lintable;
     this->linter_.lint_and_get_diagnostics_notification(
         *this->get_config(document_path), doc.doc.string(), get_raw_json(uri),

test/test-lsp-server.cpp

@@ -284,6 +284,69 @@ TEST_F(test_linting_lsp_server, opening_document_lints) {
   EXPECT_THAT(this->lint_calls, ElementsAre(u8"let x = x;"));
 }
 
+TEST_F(test_linting_lsp_server, opening_document_language_id_js_lints) {
+  this->lint_callback = [&](configuration&, padded_string_view code,
+                            string8_view uri_json, string8_view version_json,
+                            byte_buffer& notification_json) {
+    EXPECT_EQ(code, u8"let x = x;");
+    EXPECT_EQ(uri_json, u8"\"file:///test.js\"");
+    EXPECT_EQ(version_json, u8"10");
+    notification_json.append_copy(
+        u8R"--(
+              {
+                "method":"textDocument/publishDiagnostics",
+                "params":{
+                  "uri": "file:///test.js",
+                  "version": 10,
+                  "diagnostics": [
+                    {
+                      "range": {
+                        "start": {"line": 0, "character": 8},
+                        "end": {"line": 0, "character": 9}
+                      },
+                      "severity": 1,
+                        "message": "variable used before declaration: x"
+                      }
+                  ]
+                },
+                "jsonrpc":"2.0"
+              }
+            )--");
+  };
+
+  this->server.append(
+      make_message(u8R"({
+        "jsonrpc": "2.0",
+        "method": "textDocument/didOpen",
+        "params": {
+          "textDocument": {
+            "uri": "file:///test.js",
+            "languageId": "js",
+            "version": 10,
+            "text": "let x = x;"
+          }
+        }
+      })"));
+
+  ASSERT_EQ(this->client.messages.size(), 1);
+  ::Json::Value& response = this->client.messages[0];
+  EXPECT_EQ(response["method"], "textDocument/publishDiagnostics");
+  EXPECT_FALSE(response.isMember("error"));
+  // LSP PublishDiagnosticsParams:
+  EXPECT_EQ(response["params"]["uri"], "file:///test.js");
+  EXPECT_EQ(response["params"]["version"], 10);
+  ::Json::Value& diagnostics = response["params"]["diagnostics"];
+  EXPECT_EQ(diagnostics.size(), 1);
+  EXPECT_EQ(diagnostics[0]["range"]["start"]["line"], 0);
+  EXPECT_EQ(diagnostics[0]["range"]["start"]["character"], 8);
+  EXPECT_EQ(diagnostics[0]["range"]["end"]["line"], 0);
+  EXPECT_EQ(diagnostics[0]["range"]["end"]["character"], 9);
+  EXPECT_EQ(diagnostics[0]["severity"], lsp_error_severity);
+  EXPECT_EQ(diagnostics[0]["message"], "variable used before declaration: x");
+
+  EXPECT_THAT(this->lint_calls, ElementsAre(u8"let x = x;"));
+}
+
 TEST_F(test_linting_lsp_server, changing_document_with_full_text_lints) {
   this->server.append(
       make_message(u8R"({