M3.52: stop the eyedropper image-sampling test from flaking

The engine unit tests share one process, and two colour-management tests
switched the process-wide Color Settings (the working RGB space to the wide
gamut profile, Black Point Compensation off) for a moment. Any test that
showed or rendered a colour at that moment saw it through the wrong profile:
clicking_an_image_samples_its_pixel read #008181 instead of #008080.

- Move the two tests that change the Color Settings to their own test
  binary (crates/engine/tests/color_settings.rs), so no unit test can see
  non-default settings.
- The image-sampling test compares the stored colour, not its display hex.
- every_command_survives_empty_params toggles the process-wide proof view
  (Proof Colors, Overprint Preview, Separations), so it now takes the
  colour-management test lock like the tests that read that view.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/tests.rs

@@ -295,6 +295,8 @@ fn every_command_has_unique_id_and_doc() {
 #[test]
 fn every_command_survives_empty_params() {
     // Robustness: no command may panic on {} (with and without a selection).
+    // The view toggles among them flip the process-wide proof view.
+    let _proof_view = crate::tests_colormgmt::GLOBAL.lock().unwrap_or_else(|e| e.into_inner());
     for sel in [false, true] {
         for c in command_specs() {
             let mut s = session();

crates/engine/src/tests_colormgmt.rs

@@ -14,6 +14,9 @@ use vectorcraft_render::{RenderOptions, Renderer};
 use super::*;
 
 /// Every test here reads or changes the process-wide proof view or colour settings: one at a time.
+/// Tests that switch the Color Settings away from the defaults live in `tests/color_settings.rs`
+/// (their own process): every colour shown or rendered goes through them, so no lock could cover
+/// all the tests that would see the change.
 pub(crate) static GLOBAL: Mutex<()> = Mutex::new(());
 
 fn session() -> Session {
@@ -158,22 +161,6 @@ fn assign_profile_is_stored_and_undoable() {
     assert_eq!(cmd::colormgmt::doc_profiles(&s.doc().unwrap().doc), (None, None));
 }
 
-#[test]
-fn color_settings_lists_profiles_and_validates() {
-    let _g = GLOBAL.lock().unwrap_or_else(|e| e.into_inner());
-    let mut s = session();
-    let r = s.execute("edit.colorSettings", &json!({})).unwrap();
-    let names: Vec<&str> = r["profiles"].as_array().unwrap().iter().map(|p| p["name"].as_str().unwrap()).collect();
-    assert!(names.contains(&cms::GENERIC_CMYK) && names.contains(&cms::SRGB) && names.contains(&cms::DEVICE_CMYK));
-    assert!(s.execute("edit.colorSettings", &json!({"cmyk": "Missing.icc"})).is_err());
-    assert_eq!(cms::active_settings().cmyk, r["cmyk"].as_str().unwrap(), "failed change leaves settings alone");
-    let before = r["bpc"].as_bool().unwrap();
-    let r2 = s.execute("edit.colorSettings", &json!({"bpc": !before})).unwrap();
-    assert_eq!(r2["bpc"], !before);
-    s.execute("edit.colorSettings", &json!({"bpc": before})).unwrap();
-    assert!(s.execute("color.loadProfile", &json!({"path": "/nonexistent/x.icc"})).is_err());
-}
-
 #[test]
 fn proof_colors_simulate_press_on_screen() {
     let _g = GLOBAL.lock().unwrap_or_else(|e| e.into_inner());
@@ -391,24 +378,3 @@ fn intents_reach_the_document_conversion() {
     assert_ne!(first(&a), first(&b));
     let _ = Intent::Perceptual;
 }
-
-#[test]
-fn legacy_profile_name_resolves_in_commands_and_files() {
-    let _g = GLOBAL.lock().unwrap_or_else(|e| e.into_inner());
-    let (old, _) = cms::LEGACY_NAMES[0];
-    let mut s = session();
-    let before = cms::active_settings();
-    let r = s.execute("edit.colorSettings", &json!({"rgb": old})).unwrap();
-    assert_eq!(r["rgb"], cms::WIDE_GAMUT_RGB);
-    assert_eq!(cms::active_settings().rgb, cms::WIDE_GAMUT_RGB);
-    let names: Vec<&str> = r["profiles"].as_array().unwrap().iter().map(|p| p["name"].as_str().unwrap()).collect();
-    assert!(names.contains(&cms::WIDE_GAMUT_RGB) && !names.contains(&old));
-    let r = s.execute("edit.assignProfile", &json!({"rgb": old})).unwrap();
-    assert_eq!(r["rgb"], cms::WIDE_GAMUT_RGB, "stored under the current name");
-    // A document saved by an older version names the profile the old way.
-    let mut d = (*s.doc().unwrap().doc).clone();
-    d.unknown.insert(cmd::colormgmt::PROFILES_KEY.into(), json!({"rgb": old, "cmyk": null}));
-    let back = vectorcraft_format::load(&vectorcraft_format::save(&d, false)).unwrap();
-    assert_eq!(cmd::colormgmt::doc_profiles(&back), (Some(cms::WIDE_GAMUT_RGB.to_string()), None));
-    cms::set_active(&before).unwrap();
-}

crates/engine/src/tests_eyedropper.rs

@@ -163,10 +163,11 @@ fn clicking_an_image_samples_its_pixel() {
     .unwrap();
     let dst = rect(&mut s, 10.0);
     click(&mut s, 450.0, 50.0, Mods::default());
-    assert_eq!(node(&s, dst).appearance.fill_paint().color().unwrap().to_hex(), "#008080");
+    // Compared as stored (not as displayed through the working RGB space).
+    assert_eq!(node(&s, dst).appearance.fill_paint().color(), Some(Color::rgb8(0, 128, 128)));
     s.execute("eyedropper.setOptions", &json!({"sampleSize": 5})).unwrap();
     click(&mut s, 350.0, 50.0, Mods::default());
-    assert_eq!(node(&s, dst).appearance.fill_paint().color().unwrap().to_hex(), "#808040", "5 x 5 average of both pixels");
+    assert_eq!(node(&s, dst).appearance.fill_paint().color(), Some(Color::rgb8(128, 128, 64)), "5 x 5 average of both pixels");
 }
 
 #[test]

crates/engine/tests/color_settings.rs

@@ -0,0 +1,54 @@
+//! Edit → Color Settings and Assign Profile with non-default profiles. The Color Settings are
+//! process-wide and every colour shown or rendered goes through them, so these tests run in their
+//! own test binary (process) instead of next to the engine's unit tests, which would see the
+//! switched working spaces mid-test; here they take turns.
+
+use std::sync::{Mutex, MutexGuard};
+
+use serde_json::json;
+use vectorcraft_color::cms;
+use vectorcraft_engine::cmd::colormgmt::{PROFILES_KEY, doc_profiles};
+use vectorcraft_testkit::fixtures::session;
+
+/// The active Color Settings: one test at a time.
+fn settings() -> MutexGuard<'static, ()> {
+    static SETTINGS: Mutex<()> = Mutex::new(());
+    SETTINGS.lock().unwrap_or_else(|e| e.into_inner())
+}
+
+#[test]
+fn color_settings_lists_profiles_and_validates() {
+    let _g = settings();
+    let mut s = session();
+    let r = s.execute("edit.colorSettings", &json!({})).unwrap();
+    let names: Vec<&str> = r["profiles"].as_array().unwrap().iter().map(|p| p["name"].as_str().unwrap()).collect();
+    assert!(names.contains(&cms::GENERIC_CMYK) && names.contains(&cms::SRGB) && names.contains(&cms::DEVICE_CMYK));
+    assert!(s.execute("edit.colorSettings", &json!({"cmyk": "Missing.icc"})).is_err());
+    assert_eq!(cms::active_settings().cmyk, r["cmyk"].as_str().unwrap(), "failed change leaves settings alone");
+    let before = r["bpc"].as_bool().unwrap();
+    let r2 = s.execute("edit.colorSettings", &json!({"bpc": !before})).unwrap();
+    assert_eq!(r2["bpc"], !before);
+    s.execute("edit.colorSettings", &json!({"bpc": before})).unwrap();
+    assert!(s.execute("color.loadProfile", &json!({"path": "/nonexistent/x.icc"})).is_err());
+}
+
+#[test]
+fn legacy_profile_name_resolves_in_commands_and_files() {
+    let _g = settings();
+    let (old, _) = cms::LEGACY_NAMES[0];
+    let mut s = session();
+    let before = cms::active_settings();
+    let r = s.execute("edit.colorSettings", &json!({"rgb": old})).unwrap();
+    assert_eq!(r["rgb"], cms::WIDE_GAMUT_RGB);
+    assert_eq!(cms::active_settings().rgb, cms::WIDE_GAMUT_RGB);
+    let names: Vec<&str> = r["profiles"].as_array().unwrap().iter().map(|p| p["name"].as_str().unwrap()).collect();
+    assert!(names.contains(&cms::WIDE_GAMUT_RGB) && !names.contains(&old));
+    let r = s.execute("edit.assignProfile", &json!({"rgb": old})).unwrap();
+    assert_eq!(r["rgb"], cms::WIDE_GAMUT_RGB, "stored under the current name");
+    // A document saved by an older version names the profile the old way.
+    let mut d = (*s.doc().unwrap().doc).clone();
+    d.unknown.insert(PROFILES_KEY.into(), json!({"rgb": old, "cmyk": null}));
+    let back = vectorcraft_format::load(&vectorcraft_format::save(&d, false)).unwrap();
+    assert_eq!(doc_profiles(&back), (Some(cms::WIDE_GAMUT_RGB.to_string()), None));
+    cms::set_active(&before).unwrap();
+}