From e033829ef27a704e6704d51f4915b48767545c63 Mon Sep 17 00:00:00 2001
From: Vinh Tran <daivinhtran.vt@gmail.com>
Date: Thu, 20 Nov 2025 21:52:15 +0700
Subject: [PATCH] Fix diff highlights (#38384)
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Per
https://github.com/zed-industries/zed/discussions/23371#discussioncomment-13533635,
the issue is not new and I don't know how to solve the problem more
holistically yet.

All of the native themes don't have spec for `@diff.plus` and
`@diff.minus` leaving addition and deletion not being highlighted. For
diff file, the most valuable highlighting comes from exactly what we're
missing. Hence, I think this is worth fixing.

Perhaps, the ideal fix would be standardizing and documenting captures
such as `@diff.plus` and `@diff.minus` on
https://zed.dev/docs/extensions/languages#syntax-highlighting for theme
writers to adopt. But the existing list of captures seems to be
language-agnostic so I'm not sure if that's the best way forward.

Per
https://github.com/the-mikedavis/tree-sitter-diff/pull/18#issuecomment-2569785346,
`tree-sitter-diff`'s author prefers using `@keyword` and `@string` so
that `tree-sitter highlight` can work out of the box. So it seems to be
an ok choice for Zed.

Another approach is just adding `@diff.plus` and `@diff.minus` to the
native themes. Let me know if I should pursue this instead.

Before
<img width="668" height="328" alt="Screenshot 2025-09-18 at 11 16 14 AM"
src="https://github.com/user-attachments/assets/d9a5b3b5-b9ef-4e74-883f-831630fb431e"
/>

After
<img width="1011" height="404" alt="Screenshot 2025-09-18 at 12 11
15 PM"
src="https://github.com/user-attachments/assets/9cf453c0-30df-4d17-99e9-f2297865f12a"
/>
<img width="915" height="448" alt="Screenshot 2025-09-18 at 12 12 14 PM"
src="https://github.com/user-attachments/assets/9e7438a6-9009-4136-b841-1f8e1356bc9b"
/>



Closes https://github.com/zed-industries/extensions/issues/490


Release Notes:
- Fixed highlighting for addition and deletion for diff language

---------

Co-authored-by: MrSubidubi <finn@zed.dev>
---
 crates/languages/src/diff/highlights.scm | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/languages/src/diff/highlights.scm b/crates/languages/src/diff/highlights.scm
index 70ec01aa1165b6de0a23040ff3f71a32ba9fc314..4a344389032b9ff12f7c00e42adffb00721737e1 100644
--- a/crates/languages/src/diff/highlights.scm
+++ b/crates/languages/src/diff/highlights.scm
@@ -3,12 +3,14 @@
 [
   (addition)
   (new_file)
-] @diff.plus
+] @string
+;; TODO: This should eventually be `@diff.plus` with a fallback of `@string`
 
 [
   (deletion)
   (old_file)
-] @diff.minus
+] @keyword
+;; TODO: This should eventually be `@diff.minus` with a fallback of `@keyword`
 
 (commit) @constant
 
@@ -18,8 +20,6 @@
   "diff" @function
   (argument) @variable.parameter)
 
-(filename) @string.special.path
-
 (mode) @number
 
 ([