Subject: Re: bug#70345: [PATCH] 29.1.50; csharp-ts-mode indentation of if statements with single-statement body

From: Jacob Leeming <[email-masked]>
Date: Mon, 22 Apr 2024 09:50:23 +0100

> Theodor Thornhill <[email-masked]> writes:

>> Hi all,
>>
>
> Hi, Jacob!
>
>>>>From emacs -Q:
>>
>> Evaluate this elisp to set up treesitter for csharp:
>>
>> (setq treesit-language-source-alist '((c-sharp
>> "https://github.com/tree-sitter/tree-sitter-c-sharp" "master" "src"))
>>       treesit-load-name-override-list '((c-sharp
>> "libtree-sitter-csharp" "tree_sitter_c_sharp"))
>>       major-mode-remap-alist '((csharp-mode . csharp-ts-mode)))
>>
>> Insert the following text into a csharp-ts-mode buffer:
>>
>> if (true)
>> var x = 2;
>>
>> Try to indent the variable declaration of the function with
>> indent-for-tab-command. Nothing will happen. I'd expect to see this:
>>
>> if (true)
>>     var x = 2;
>>
>> This issue can be fixed with the following patch:
>>
>> diff --git a/lisp/progmodes/csharp-mode.el b/lisp/progmodes/csharp-mode.el
>> index 53c52e6..1a7d535 100644
>> --- a/lisp/progmodes/csharp-mode.el
>> +++ b/lisp/progmodes/csharp-mode.el
>> @@ -678,7 +678,8 @@ csharp-ts-mode--indent-rules
>>       ((parent-is "binary_expression") parent 0)
>>       ((parent-is "block") parent-bol csharp-ts-mode-indent-offset)
>>       ((parent-is "local_function_statement") parent-bol 0)
>> -     ((parent-is "if_statement") parent-bol 0)
>> +     ((match "block" "if_statement") parent-bol 0)
>> +     ((parent-is "if_statement") parent-bol csharp-ts-mode-indent-offset)
>>       ((parent-is "for_statement") parent-bol 0)
>>       ((parent-is "for_each_statement") parent-bol 0)
>>       ((parent-is "while_statement") parent-bol 0)
>>
>
> Looks good to me. Are you willing to pack this up with a nice test
> confirming the behavior?
>
> All the best,
> Theo

Thanks all,

Discovered we had a similar issue for else blocks. Wrote a test that
covers both cases.

See the attached diff which contains my changes to the indent rules and
the test.

Cheers,
Jacob

>From cd86e2e3fbe596b999f4cfd9655f0a37ac3845d2 Mon Sep 17 00:00:00 2001
From: Jacob Leeming <[email-masked]>
Date: Mon, 22 Apr 2024 09:49:15 +0100
Subject: [PATCH] indent single statement if in csharp-ts-mode

bug#70345
---
 lisp/progmodes/csharp-mode.el                 |  4 +-
 .../csharp-ts-mode-resources/indent.erts      | 51 +++++++++++++++++++
 test/lisp/progmodes/csharp-ts-mode-tests.el   | 30 +++++++++++
 3 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 test/lisp/progmodes/csharp-ts-mode-resources/indent.erts
 create mode 100644 test/lisp/progmodes/csharp-ts-mode-tests.el

diff --git a/lisp/progmodes/csharp-mode.el b/lisp/progmodes/csharp-mode.el
index 607360f737a..62bbbfe02ff 100644
--- a/lisp/progmodes/csharp-mode.el
+++ b/lisp/progmodes/csharp-mode.el
@@ -689,7 +689,9 @@ csharp-ts-mode--indent-rules
      ((parent-is "binary_expression") parent 0)
      ((parent-is "block") parent-bol csharp-ts-mode-indent-offset)
      ((parent-is "local_function_statement") parent-bol 0)
-     ((parent-is "if_statement") parent-bol 0)
+     ((match "block" "if_statement") parent-bol 0)
+     ((match "else" "if_statement") parent-bol 0)
+     ((parent-is "if_statement") parent-bol csharp-ts-mode-indent-offset)
      ((parent-is "for_statement") parent-bol 0)
      ((parent-is "for_each_statement") parent-bol 0)
      ((parent-is "while_statement") parent-bol 0)
diff --git a/test/lisp/progmodes/csharp-ts-mode-resources/indent.erts b/test/lisp/progmodes/csharp-ts-mode-resources/indent.erts
new file mode 100644
index 00000000000..3cb23608270
--- /dev/null
+++ b/test/lisp/progmodes/csharp-ts-mode-resources/indent.erts
@@ -0,0 +1,51 @@
+Code:
+  (lambda ()
+    (csharp-ts-mode)
+    (indent-region (point-min) (point-max)))
+
+Point-Char: |
+
+Name: Indent single statement body for if/else. (bug#70345)
+
+=-=
+
+int x;
+int y;
+
+if (true)
+    x = 2;
+
+if (true)
+{
+    x = 2;
+}
+
+if (true)
+    x = 2;
+else
+    y = 2;
+
+if (true)
+{
+    x = 2;
+}
+else
+{
+    y = 2;
+}
+
+if (true)
+    x = 2;
+else
+{
+    y = 2;
+}
+
+if (true)
+{
+    x = 2;
+}
+else
+    y = 2;
+
+=-=-=
diff --git a/test/lisp/progmodes/csharp-ts-mode-tests.el b/test/lisp/progmodes/csharp-ts-mode-tests.el
new file mode 100644
index 00000000000..0df0211d86b
--- /dev/null
+++ b/test/lisp/progmodes/csharp-ts-mode-tests.el
@@ -0,0 +1,30 @@
+;;; csharp-ts-mode-tests.el --- Tests for Tree-sitter-based C# mode  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2024 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/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'ert-x)
+(require 'csharp-mode)
+
+(ert-deftest csharp-ts-mode-test-indentation ()
+  (ert-test-erts-file (ert-resource-file "indent.erts")))
+
+(provide 'csharp-ts-mode-tests)
+;;; csharp-ts-mode-tests.el ends here
-- 
2.39.2