[elpa] externals/firefox-javascript-repl 563ae0984c 01/24: firefox-javascript-repl: New package

[Thomas Fitzsimmons]

branch: externals/firefox-javascript-repl
commit 563ae0984c5a552af19eaac736c518194ff2c4cd
Author: Thomas Fitzsimmons <fitzsim@fitzsim.org>
Commit: Thomas Fitzsimmons <fitzsim@fitzsim.org>

    firefox-javascript-repl: New package
    
    * firefox-javascript-repl.el: New file.
---
 firefox-javascript-repl.el | 87 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

diff --git a/firefox-javascript-repl.el b/firefox-javascript-repl.el
new file mode 100644
index 0000000000..2e1311bcf4
--- /dev/null
+++ b/firefox-javascript-repl.el
@@ -0,0 +1,87 @@
+;;; firefox-javascript-repl.el --- Jack into Firefox -*- lexical-binding: t -*-
+
+;; Copyright (C) 2023 Free Software Foundation, Inc.
+
+;; Author: Thomas Fitzsimmons <fitzsim@fitzsim.org>
+;; Version: 1.0.0
+
+;; This program 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.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; REPL into a new Firefox instance's JavaScript engine.
+
+;; Installation:
+
+;; M-x package-install RET firefox-javascript-repl RET
+
+;; Usage:
+
+;; M-x firefox-javascript-repl RET
+
+;;; Code:
+(defcustom firefox-javascript-repl-binary "firefox"
+  "The name or full path of the firefox binary to run."
+  :group 'external
+  :type 'string)
+
+(defun firefox-javascript-repl--create-profile-directory ()
+  "Create a profile directory."
+  (let ((profile-directory (make-temp-file "firefox-javascript-repl-" t)))
+    (with-current-buffer
+        (find-file-noselect (expand-file-name "user.js" profile-directory))
+      (insert "user_pref(\"devtools.debugger.remote-enabled\", true);\n")
+      (insert "user_pref(\"devtools.chrome.enabled\", true);\n")
+      (insert "user_pref(\"devtools.debugger.prompt-connection\", false);\n")
+      (save-buffer 0))
+    profile-directory))
+
+(defun firefox-javascript-repl ()
+  "Run a new instance of Firefox in a new profile.
+Set about:config values `devtools.debugger.remote-enabled' to
+true, `devtools.chrome.enabled' to true,
+`devtools.debugger.prompt-connection' to false, and pass
+`-start-debugger-server'.  Firefox will listen on
+localhost (127.0.0.1) TCP port 6000."
+  (interactive)
+  (when (not (process-status "firefox-javascript-repl"))
+    (let* ((profile-directory
+            (firefox-javascript-repl--create-profile-directory))
+           (process-name (file-name-nondirectory profile-directory))
+           (firefox-process
+            (start-process "firefox-javascript-repl"
+                           process-name
+                           firefox-javascript-repl-binary
+                           "about:blank"
+                           "-profile" profile-directory
+                           "-start-debugger-server")))
+      (set-process-sentinel firefox-process
+                            (lambda (process event)
+                              (message "%S %S" process event)
+                              (when (or (string= event "killed\n")
+                                        (string= event "finished\n"))
+                                (message
+                                 "firefox-javascript-repl: %s %s; deleting %s"
+                                 process (string-trim event) profile-directory)
+                                (delete-directory profile-directory t))))
+      nil)))
+
+(defun firefox-javascript-repl-stop ()
+  "Stop the Firefox process started by `firefox-javascript-repl'."
+  (interactive)
+  (kill-process "firefox-javascript-repl"))
+
+(provide 'firefox-javascript-repl)
+
+;;; firefox-javascript-repl.el ends here