pcomplete: Generate completions from --help messages

* lisp/pcomplete.el (pcomplete-from-help): New function (and hash
table) to get pcomplete candidates from help messages.
(pcomplete-here-using-help): Helper function to define pcomplete for
simple commands
(pcomplete-completions-at-point): Provide annotation-function and
company-docsig properties.
* lisp/pcmpl-git.el: New file, provides pcomplete for Git.
* lisp/pcmpl-gnu.el: Add pcomplete for awk, gpg and gdb, emacs and
emacsclient.
* lisp/pcmpl-linux.el: Add pcomplete for systemctl and journalctl.
* lisp/pcmpl-rpm.el: Add pcomplete for dnf.
* lisp/pcmpl-unix.el: Add pcomplete for sudo and most commands found
in GNU Coreutils.
* lisp/pcmpl-x.el: Add pcomplete for tex, pdftex, latex, pdflatex,
rigrep and rclone.
* test/lisp/pcomplete-tests.el (pcomplete-test-parse-gpg-help,
pcomplete-test-parse-git-help): Tests for the new functions.

1 files changed, 100 insertions, 0 deletions

diff --git a/test/lisp/pcomplete-tests.el b/test/lisp/pcomplete-tests.el
new file mode 100644
index 00000000000..00a82502f30
--- /dev/null
+++ b/test/lisp/pcomplete-tests.el
@@ -0,0 +1,100 @@
+;;; pcomplete-tests.el --- Tests for pcomplete.el  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2022 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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.
+
+;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+(require 'pcomplete)
+
+(ert-deftest pcomplete-test-parse-gpg-help ()
+  (cl-letf ((pcomplete-from-help (make-hash-table :test #'equal))
+            ((symbol-function 'call-process)
+             (lambda (&rest _) (insert "\
+gpg (GnuPG) 2.3.7
+
+Commands:
+
+ -s, --sign                         make a signature
+     --clear-sign                   make a clear text signature
+ -b, --detach-sign                  make a detached signature
+     --tofu-policy VALUE            set the TOFU policy for a key
+
+Options to specify keys:
+ -r, --recipient USER-ID            encrypt for USER-ID
+ -u, --local-user USER-ID           use USER-ID to sign or decrypt
+
+(See the man page for a complete listing of all commands and options)
+
+Examples:
+
+ -se -r Bob [file]          sign and encrypt for user Bob
+ --clear-sign [file]        make a clear text signature
+"))))
+    (should
+     (equal-including-properties
+      (pcomplete-from-help "gpg --help" :narrow-end "^ -se")
+      '(#("-s" 0 1 (pcomplete-help "make a signature"))
+        #("--sign" 0 1 (pcomplete-help "make a signature"))
+        #("--clear-sign" 0 1 (pcomplete-help "make a clear text signature"))
+        #("-b" 0 1 (pcomplete-help "make a detached signature"))
+        #("--detach-sign" 0 1 (pcomplete-help "make a detached signature"))
+        #("--tofu-policy" 0 1
+          (pcomplete-help "set the TOFU policy for a key" pcomplete-annotation " VALUE"))
+        #("-r" 0 1 (pcomplete-help "encrypt for USER-ID"))
+        #("--recipient" 0 1
+          (pcomplete-help "encrypt for USER-ID" pcomplete-annotation " USER-ID"))
+        #("-u" 0 1
+          (pcomplete-help "use USER-ID to sign or decrypt"))
+        #("--local-user" 0 1
+          (pcomplete-help "use USER-ID to sign or decrypt" pcomplete-annotation " USER-ID")))))))
+
+(ert-deftest pcomplete-test-parse-git-help ()
+  (cl-letf ((pcomplete-from-help (make-hash-table :test #'equal))
+            ((symbol-function 'call-process)
+             (lambda (&rest _) (insert "\
+usage: git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]
+           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
+           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]
+           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
+           [--super-prefix=<path>] [--config-env=<name>=<envvar>]
+           <command> [<args>]
+"))))
+    (should
+     (equal-including-properties
+      (pcomplete-from-help "git help"
+                           :margin "\\(\\[\\)-"
+                           :separator " | "
+                           :description "\\`")
+      '("-v" "--version" "-h" "--help"
+        #("-C" 0 1 (pcomplete-annotation " <path>"))
+        #("-c" 0 1 (pcomplete-annotation " <name>"))
+        #("--exec-path" 0 1 (pcomplete-annotation "[=<path>]"))
+        "--html-path" "--man-path" "--info-path"
+        "-p" "--paginate" "-P" "--no-pager"
+        "--no-replace-objects" "--bare"
+        #("--git-dir=" 0 1 (pcomplete-annotation "<path>"))
+        #("--work-tree=" 0 1 (pcomplete-annotation "<path>"))
+        #("--namespace=" 0 1 (pcomplete-annotation "<name>"))
+        #("--super-prefix=" 0 1 (pcomplete-annotation "<path>"))
+        #("--config-env=" 0 1 (pcomplete-annotation "<name>")))))))
+
+(provide 'pcomplete-tests)
+;;; pcomplete-tests.el ends here