Re: [PATCH] Update js-mode function heading regexes

[Adam Niederer <adam.niederer@gmail.com>]

> These are manual tests, right? 'make check' doesn't sound relevant. 
> But we have some automated tests for js.el too. Check out
> test/lisp/progmodes/js-tests.el. Maybe these scenarios would be better
> coded with ERT. 
The file I included was primarily for visual evaluation of the changes.
Adding some automated tests is a good idea, though, so I've included an
updated patchset below. This also makes js--function-heading-2-re work
on async functions.
> Not much. Patch submissions via the bug tracker have higher odds of
> not being forgotten is they're not applied right away, though.
>
> Thanks for the patch.

Would reposting these changes to bug-gnu-emacs be a good idea?

Thanks a lot,

-Adam

--- a/lisp/progmodes/js.el
+++ b/lisp/progmodes/js.el
@@ -250,20 +250,20 @@ js--available-frameworks
 
 (defconst js--function-heading-1-re
   (concat
-   "^\\s-*function\\(?:\\s-\\|\\*\\)+\\(" js--name-re "\\)")
+   "^\\s-*\\(?:async\\s-+\\)?function\\(?:\\s-\\|\\*\\)+\\("
js--name-re "\\)")
   "Regexp matching the start of a JavaScript function header.
 Match group 1 is the name of the function.")
 
 (defconst js--function-heading-2-re
   (concat
-   "^\\s-*\\(" js--name-re "\\)\\s-*:\\s-*function\\_>")
+   "^.*?\\(" js--name-re "\\)\\s-*:\\s-*\\(?:async\\s-+\\)?function\\_>")
   "Regexp matching the start of a function entry in an associative array.
 Match group 1 is the name of the function.")
 
 (defconst js--function-heading-3-re
   (concat
-   "^\\s-*\\(?:var\\s-+\\)?\\(" js--dotted-name-re "\\)"
-   "\\s-*=\\s-*function\\_>")
+   "^\\s-*\\(?:\\(?:var\\|let\\|const\\)\\s-+\\)?\\("
js--dotted-name-re "\\)"
+   "\\s-*=\\s-*\\(?:async\\s-+\\)?function\\_>")
   "Regexp matching a line in the JavaScript form \"var MUMBLE = function\".
 Match group 1 is MUMBLE.")

diff --git a/test/lisp/progmodes/js-tests.el
b/test/lisp/progmodes/js-tests.el
index 8e1bac10cd..313e2e2e52 100644
--- a/test/lisp/progmodes/js-tests.el
+++ b/test/lisp/progmodes/js-tests.el
@@ -177,6 +177,44 @@
     ;; The bug was a hang.
     (should t)))
 
+(ert-deftest js-mode-highlight-function-names ()
+  "Ensure js--function-heading-1-re and js--function-heading-2-re match all
+possible function declarations and highlight the function names
accordingly."
+  (with-temp-buffer
+    (js-mode)
+    (insert "function foo() {}\n"
+            "async function bar() {}\n"
+            "let x = [{ baz: function() {}\n"
+            "           quux: function() {}\n"
+            "           kek: async function() {}\n"
+            "/**/       bur: async function() {} }]\n")
+    (font-lock-ensure)
+    (dolist (name '("foo" "bar" "baz" "quux" "kek" "bur"))
+      (save-excursion
+        (search-backward name)
+        (should (equal (face-at-point) font-lock-function-name-face))))))
+
+(ert-deftest js-mode-accept-function-bindings ()
+  "Ensure js--function-heading-3-re matches all function declarations
of the
+form (var|let|const) foo = (async)? function."
+  (with-temp-buffer
+    (js-mode)
+    (insert "var foo = async function() {}\n"
+            "const bar = async function() {}\n"
+            "let baz = async function() {}\n"
+            "var quux = function() {}\n"
+            "const kek = function() {}\n"
+            "let bur = function() {}\n")
+    (dolist (name '("foo" "bar" "baz" "quux" "kek" "bur"))
+      ;; re-search-backward will throw if one the strings doesn't match.
+      (re-search-backward js--function-heading-3-re))
+    ;; Ensure we have exactly six matches
+    (should-error (re-search-backward js--function-heading-3-re))))
+
 (provide 'js-tests)
 
 ;;; js-tests.el ends here