branch: externals/eglot
commit 3922cf323ca700046ed0507fa4d534e3d5413297
Author: João Távora <[email protected]>
Commit: João Távora <[email protected]>
Per #144, #156: control strictness towards incoming LSP messages
A new variable, eglot-strict-mode controls whether Eglot is strict or
lax with regard to incoming LSP messages.
1. Bug reports should be tested with eglot-strict-mode set to
'(disallow-non-standard-keys enforce-required-keys)
2. Users struggling to get non-standard servers working set this
variable to '(), nil. For now, by popular demand, this is the
default value.
Note that this commit in particular introduces a new infrastructure,
but does not yet alter any code in Eglot to use it. Neither is the
variable eglot--lsp-interface-alist populated.
* eglot-tests.el (eglot-strict-interfaces): New test.
* eglot.el (eglot--lsp-interface-alist): New variable.
(eglot-strict-mode): New variable.
(eglot--call-with-interface): New helper.
(eglot--dbind): New macro.
(eglot--lambda): New macro.
---
eglot-tests.el | 36 ++++++++++++++++++++++++
eglot.el | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 124 insertions(+)
diff --git a/eglot-tests.el b/eglot-tests.el
index 6cea929..5d69dcf 100644
--- a/eglot-tests.el
+++ b/eglot-tests.el
@@ -578,6 +578,10 @@ Pass TIMEOUT to `eglot--with-timeout'."
`((python-mode . ("sh" "-c" "sleep 2 && pyls")))))
(should-error (apply #'eglot--connect (eglot--guess-contact)))))))
+
+
+;;; Unit tests
+;;;
(ert-deftest eglot-capabilities ()
"Unit test for `eglot--server-capable'."
(cl-letf (((symbol-function 'eglot--capabilities)
@@ -600,6 +604,38 @@ Pass TIMEOUT to `eglot--with-timeout'."
(should-not (eglot--server-capable :foobarbaz))
(should-not (eglot--server-capable :textDocumentSync :foobarbaz))))
+
+(ert-deftest eglot-strict-interfaces ()
+ (let ((eglot--lsp-interface-alist
+ `((FooObject . ((:foo :bar) (:baz))))))
+ (should-error
+ (let ((eglot-strict-mode '(disallow-non-standard-keys)))
+ (eglot--dbind nil (&key foo bar) `(:foo "foo" :bar "bar" :fotrix bargh)
+ (cons foo bar))))
+ (should
+ (equal '("foo" . "bar")
+ (let ((eglot-strict-mode nil))
+ (eglot--dbind nil (&key foo bar) `(:foo "foo" :bar "bar" :fotrix
bargh)
+ (cons foo bar)))))
+ (should-error
+ (let ((eglot-strict-mode '(disallow-non-standard-keys)))
+ (eglot--dbind FooObject (&key foo bar) `(:foo "foo" :bar "bar" :fotrix
bargh)
+ (cons foo bar))))
+ (should
+ (equal '("foo" . "bar")
+ (let ((eglot-strict-mode '(disallow-non-standard-keys)))
+ (eglot--dbind FooObject (&key foo bar) `(:foo "foo" :bar "bar"
:baz bargh)
+ (cons foo bar)))))
+ (should
+ (equal '("foo" . "bar")
+ (let ((eglot-strict-mode '(enforce-required-keys)))
+ (eglot--dbind FooObject (&key foo bar) `(:foo "foo" :bar "bar"
:baz bargh)
+ (cons foo bar)))))
+ (should-error
+ (let ((eglot-strict-mode '(enforce-required-keys)))
+ (eglot--dbind FooObject (&key foo bar) `(:foo "foo" :baz bargh)
+ (cons foo bar))))))
+
(provide 'eglot-tests)
;;; eglot-tests.el ends here
diff --git a/eglot.el b/eglot.el
index 365b5d2..4996f5b 100644
--- a/eglot.el
+++ b/eglot.el
@@ -197,6 +197,94 @@ let the buffer grow forever."
(13 . "Enum") (14 . "Keyword") (15 . "Snippet") (16 . "Color")
(17 . "File") (18 . "Reference")))
+
+
+;;; Message verification helpers
+;;;
+(defvar eglot--lsp-interface-alist `()
+ "Alist (INTERFACE-NAME . INTERFACE) of known external LSP interfaces.
+
+INTERFACE-NAME is a symbol designated by the spec as \"export
+interface\". INTERFACE is a list (REQUIRED OPTIONAL) where
+REQUIRED and OPTIONAL are lists of keyword symbols designating
+field names that must be, or may be, respectively, present in a
+message adhering to that interface.
+
+Here's what an element of this alist might look like:
+
+ (CreateFile . ((:kind :uri) (:options)))")
+
+(defvar eglot-strict-mode '()
+ "How strictly Eglot vetoes LSP messages from server.
+
+Value is a list of symbols:
+
+If a list containing the symbol `disallow-non-standard-keys', an
+error is raised if any non-standard fields are sent by the
+server.
+
+If the list containing the symbol `enforce-required-keys', an error
+is raised if any required fields are missing from the message.
+
+If the list is empty, any non-standard fields sent by the server
+and missing required fields are accepted (which may or may not
+cause problems in Eglot's functioning later on).")
+
+(defun eglot--call-with-interface (interface object fn)
+ "Call FN, but first check that OBJECT conforms to INTERFACE.
+
+INTERFACE is a key to `eglot--lsp-interface-alist' and OBJECT is
+ a plist representing an LSP message."
+ (let* ((entry (assoc interface eglot--lsp-interface-alist))
+ (required (car (cdr entry)))
+ (optional (cadr (cdr entry))))
+ (when (memq 'enforce-required-keys eglot-strict-mode)
+ (cl-loop for req in required
+ when (eq 'eglot--not-present
+ (cl-getf object req 'eglot--not-present))
+ collect req into missing
+ finally (when missing
+ (eglot--error
+ "A `%s' must have %s" interface missing))))
+ (when (and entry (memq 'disallow-non-standard-keys eglot-strict-mode))
+ (cl-loop
+ with allowed = (append required optional)
+ for (key _val) on object by #'cddr
+ unless (memq key allowed) collect key into disallowed
+ finally (when disallowed
+ (eglot--error
+ "A `%s' mustn't have %s" interface disallowed))))
+ (funcall fn)))
+
+(cl-defmacro eglot--dbind (interface lambda-list object &body body)
+ "Destructure OBJECT of INTERFACE as CL-LAMBDA-LIST.
+Honour `eglot-strict-mode'."
+ (declare (indent 3))
+ (let ((fn-once `(lambda () ,@body))
+ (lax-lambda-list (if (memq '&allow-other-keys lambda-list)
+ lambda-list
+ (append lambda-list '(&allow-other-keys))))
+ (strict-lambda-list (delete '&allow-other-keys lambda-list)))
+ (if interface
+ `(cl-destructuring-bind ,lax-lambda-list ,object
+ (eglot--call-with-interface ',interface ,object ,fn-once))
+ (let ((object-once (make-symbol "object-once")))
+ `(let ((,object-once ,object))
+ (if (memq 'disallow-non-standard-keys eglot-strict-mode)
+ (cl-destructuring-bind ,strict-lambda-list ,object-once
+ (funcall ,fn-once))
+ (cl-destructuring-bind ,lax-lambda-list ,object-once
+ (funcall ,fn-once))))))))
+
+(cl-defmacro eglot--lambda (interface cl-lambda-list &body body)
+ "Function of args CL-LAMBDA-LIST for processing INTERFACE objects.
+Honour `eglot-strict-mode'."
+ (declare (indent 2))
+ (let ((e (cl-gensym "jsonrpc-lambda-elem")))
+ `(lambda (,e)
+ (eglot--dbind ,interface ,cl-lambda-list ,e
+ ,@body))))
+
;;; API (WORK-IN-PROGRESS!)
;;;
