From 845e68008b0d81c5faf6cdc4b87ac928d28cfbfe Mon Sep 17 00:00:00 2001
From: FredApps <153173854+FredApps@users.noreply.github.com>
Date: Sun, 15 Nov 2026 15:48:44 +0100
Subject: [PATCH] test(trace): keep the image crate's JPEG encoder for the
 block-artifact fixture

a_jpegs_blocks_are_not_traced_as_steps measures how many traced edges land
on JPEG block boundaries, which depends on the encoder's artifacts. With the
craft-image-codecs encoder 18 of 40 segments sit on block edges; with the
original encoder and the new shared decoder the test passes unchanged, so
the trace itself is unaffected. image stays a dev-dependency only.
---
 Cargo.lock                |  1 +
 crates/trace/Cargo.toml   |  2 ++
 crates/trace/src/tests.rs | 10 ++++++----
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index b58c015a5c..d80b61462e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7034,6 +7034,7 @@ name = "vectorcraft-trace"
 version = "0.24.1"
 dependencies = [
  "craft-image-codecs",
+ "image",
  "kurbo 0.13.1",
  "serde",
  "serde_json",
diff --git a/crates/trace/Cargo.toml b/crates/trace/Cargo.toml
index 83f7425c05..ad76667886 100644
--- a/crates/trace/Cargo.toml
+++ b/crates/trace/Cargo.toml
@@ -17,3 +17,5 @@ thiserror = { workspace = true }
 
 [dev-dependencies]
 serde_json = { workspace = true }
+# Test fixtures only: the JPEG-block test needs the block artifacts of the encoder it was tuned on.
+image = { workspace = true }
diff --git a/crates/trace/src/tests.rs b/crates/trace/src/tests.rs
index 9b73fe784a..6b0f3d3b32 100644
--- a/crates/trace/src/tests.rs
+++ b/crates/trace/src/tests.rs
@@ -2174,12 +2174,14 @@ fn small_accents_of_other_colors_leave_a_tinted_photo_continuous_tone() {
     }
 }
 
-/// `img` saved as a JPEG of `quality` and read back.
+/// `img` saved as a JPEG of `quality` and read back. The `image` crate's encoder stays the fixture:
+/// `a_jpegs_blocks_are_not_traced_as_steps` measures block artifacts, which differ by encoder.
 fn through_jpeg(img: &Raster, quality: u8) -> Raster {
     let rgb: Vec<u8> = img.rgba.chunks(4).flat_map(|p| [p[0], p[1], p[2]]).collect();
-    let encoded = craft_image_codecs::Image::from_u8(img.width, img.height, craft_image_codecs::ChannelLayout::Rgb, rgb).unwrap();
-    let opts = craft_image_codecs::EncodeOptions { jpeg_quality: quality, ..Default::default() };
-    let bytes = craft_image_codecs::encode(&encoded, craft_image_codecs::Format::Jpeg, &opts).unwrap();
+    let mut bytes = vec![];
+    image::codecs::jpeg::JpegEncoder::new_with_quality(&mut bytes, quality)
+        .encode(&rgb, img.width, img.height, image::ExtendedColorType::Rgb8)
+        .unwrap();
     Raster::decode(&bytes).unwrap()
 }