Make flycheck-eldev' properly work on files Eldev' and `Eldev-local…

…' as long as those are byte-compilable.

Eldev

@@ -1,4 +1,4 @@
-; -*- mode: emacs-lisp; lexical-binding: t; no-byte-compile: t -*-
+; -*- mode: emacs-lisp; lexical-binding: t -*-
 
 (eldev-require-version "0.5")
 

README.adoc

@@ -37,6 +37,10 @@ require that.
 * Additional test dependencies (see `eldev-add-extra-dependencies`)
   are seen from the test files, but not from the main files.
 
+* Also checks files `Eldev` and `Eldev-local` (as long as they are
+  byte-compilable, but this is a common Flycheck requirement).  Detect
+  wrong `(eldev-...)` function calls as you type!
+
 == Installation
 
 Download and install the package from {uri-melpa-stable}[MELPA Stable]

flycheck-eldev.el

@@ -228,6 +228,11 @@ If FROM is nil, search from `default-directory'."
               (setf eval-forms `(,(flycheck-emacs-lisp-bytecomp-config-form) ,flycheck-emacs-lisp-check-form)))
             ;; Explicitly specify various options in case a user has different defaults.
             `("--as-is" "--load-newer"
+              ;; Don't load file `Eldev' or `Eldev-local' if we are checking it.
+              ,@(cond ((file-equal-p real-filename "Eldev")
+                       `("--setup-first" ,(flycheck-sexp-to-string '(setf eldev-skip-project-config t))))
+                      ((file-equal-p real-filename "Eldev-local")
+                       `("--setup-first" ,(flycheck-sexp-to-string '(setf eldev-skip-local-project-config t)))))
               ;; Ignore the original file for project initialization purposes.  If
               ;; `eldev-project-main-file' is specified, this does nothing.
               "--setup-first"
@@ -302,6 +307,17 @@ If FROM is nil, search from `default-directory'."
     (flycheck-filter-errors errors 'emacs-lisp)))
 
 
+(defvar flycheck-eldev--original-emacs-lisp-enabled-p nil)
+
+;; Easier to hack than to wait for https://github.com/flycheck/flycheck/pull/1832 to be
+;; "reviewed".  Disable `checkdoc' on Eldev files, it makes zero sense there.
+(defun flycheck-eldev--emacs-lisp-checkdoc-enabled-p ()
+  "Check whether to enable Emacs Lisp Checkdoc in the current buffer."
+  (and (funcall flycheck-eldev--original-emacs-lisp-enabled-p)
+       ;; These files are valid Lisp, but don't contain "standard" comments.
+       (not (member (file-name-base (or (buffer-file-name) "-")) '("Eldev" "Eldev-local")))))
+
+
 ;;;###autoload
 (defun flycheck-eldev--initialize ()
   (add-to-list 'flycheck-checkers 'elisp-eldev)
@@ -335,7 +351,11 @@ See Info Node `(elisp)Byte Compilation'."
                 (process-put process 'flycheck-working-directory (file-name-directory (buffer-file-name))))
               process))))
   ;; I don't think we need a separate package just for this, so let's do it here.
-  (add-to-list 'auto-mode-alist `(,(rx "/" (or "Eldev" "Eldev-local") eos) . emacs-lisp-mode) t))
+  (add-to-list 'auto-mode-alist `(,(rx "/" (or "Eldev" "Eldev-local") eos) . emacs-lisp-mode) t)
+  ;; Hack in disabling of `checkdoc' on Eldev files.
+  (unless flycheck-eldev--original-emacs-lisp-enabled-p
+    (setf flycheck-eldev--original-emacs-lisp-enabled-p        (flycheck-checker-get 'emacs-lisp-checkdoc 'enabled)
+          (flycheck-checker-get 'emacs-lisp-checkdoc 'enabled) #'flycheck-eldev--emacs-lisp-checkdoc-enabled-p)))
 
 
 ;;;###autoload

test/flycheck-eldev-test.el

@@ -10,14 +10,18 @@
   (declare (indent 1) (debug (sexp body)))
   (let ((flycheck-eldev-whitelist        nil)
         (flycheck-eldev-blacklist        nil)
-        (flycheck-eldev-unknown-projects 'trust))
+        (flycheck-eldev-unknown-projects 'trust)
+        (enabled-checkers                '(emacs-lisp elisp-eldev)))
     (while (keywordp (car body))
       (pcase (pop body)
         (:whitelist        (setf flycheck-eldev-whitelist        (pop body)))
         (:blacklist        (setf flycheck-eldev-blacklist        (pop body)))
-        (:unknown-projects (setf flycheck-eldev-unknown-projects (pop body)))))
+        (:unknown-projects (setf flycheck-eldev-unknown-projects (pop body)))
+        (:enable-checkdoc  (if (pop body)
+                               (push 'emacs-lisp-checkdoc enabled-checkers)
+                             (setf enabled-checkers (delq 'emacs-lisp-checkdoc enabled-checkers))))))
     ;; Don't use `emacs-lisp-checkdoc'.
-    `(let ((flycheck-checkers                   (--filter (memq it '(emacs-lisp elisp-eldev)) flycheck-checkers))
+    `(let ((flycheck-checkers                   (--filter (memq it ',enabled-checkers) flycheck-checkers))
            (flycheck-disabled-checkers          nil)
            (flycheck-check-syntax-automatically nil)
            (flycheck-eldev-whitelist            ',flycheck-eldev-whitelist)
@@ -77,6 +81,14 @@
     (flycheck-eldev--test-recheck)
     (flycheck-eldev--test-expect-no-errors)))
 
+(ert-deftest flycheck-eldev-basics-2 ()
+  (flycheck-eldev--test "project-a/Eldev"
+    ;; Enable `checkdoc'.  Must be disabled at runtime (currently through our own hack)
+    ;; for the test to pass.
+    :enable-checkdoc t
+    (flycheck-eldev--test-recheck)
+    (flycheck-eldev--test-expect-no-errors)))
+
 (ert-deftest flycheck-eldev-self-1 ()
   (flycheck-eldev--test "../flycheck-eldev.el"
     (flycheck-eldev--test-recheck)
@@ -87,6 +99,17 @@
     (flycheck-eldev--test-recheck)
     (flycheck-eldev--test-expect-no-errors)))
 
+;; This indirectly tests that we see functions in `eldev' namespace from `Eldev' and
+;; `Eldev-local'.  Unfortunately, we also see them in normal files, but I cannot think of
+;; a robust way to avoid this currently.
+(ert-deftest flycheck-eldev-self-3 ()
+  (flycheck-eldev--test "../Eldev"
+    ;; Enable `checkdoc'.  Must be disabled at runtime (currently through our own hack)
+    ;; for the test to pass.
+    :enable-checkdoc t
+    (flycheck-eldev--test-recheck)
+    (flycheck-eldev--test-expect-no-errors)))
+
 (ert-deftest flycheck-eldev-test-file-1 ()
   (flycheck-eldev--test "project-a/test/project-a.el"
     (flycheck-eldev--test-recheck)
@@ -117,11 +140,27 @@
 ;; Test that faulty project initialization code is handled fine.
 (ert-deftest flycheck-eldev-faulty-eldev-local-1 ()
   (flycheck-eldev--test-with-temp-file "project-a/Eldev-local"
-      (insert "this is not a valid Lisp")
+      (insert "this-variable-certainly-doesnt-exist")
     (flycheck-eldev--test "project-a/project-a.el"
       (flycheck-eldev--test-recheck)
       (flycheck-eldev--test-expect-errors '(:matches "cannot be initialized")))))
 
+;; When checking the faulty `Eldev-local', we must not use it for initialization.
+(ert-deftest flycheck-eldev-faulty-eldev-local-2 ()
+  (flycheck-eldev--test-with-temp-file "project-a/Eldev-local"
+      (insert "this-variable-certainly-doesnt-exist")
+    (flycheck-eldev--test "project-a/Eldev-local"
+      (flycheck-eldev--test-recheck)
+      (flycheck-eldev--test-expect-errors '(:matches "this-variable-certainly-doesnt-exist")))))
+
+;; Test that `flycheck-eldev' really works on Eldev files if those are byte-compilable.
+(ert-deftest flycheck-eldev-suspicious-eldev-local-1 ()
+  (flycheck-eldev--test-with-temp-file "project-a/Eldev-local"
+      (insert "(defun just-for-testing () (function-with-this-name-certainly-doesnt-exist))")
+    (flycheck-eldev--test "project-a/Eldev-local"
+      (flycheck-eldev--test-recheck)
+      (flycheck-eldev--test-expect-errors '(:matches "function-with-this-name-certainly-doesnt-exist")))))
+
 
 (ert-deftest flycheck-eldev-project-trusted-p-1 ()
   (let ((flycheck-eldev-whitelist        nil)

test/project-a/Eldev

@@ -1,4 +1,4 @@
-; -*- mode: emacs-lisp; lexical-binding: t; no-byte-compile: t -*-
+; -*- mode: emacs-lisp; lexical-binding: t -*-
 
 (eldev-use-package-archive `("archive-a" . ,(expand-file-name "../package-archive-a")))