M3.72: Tile Edge Color dialog and Show Swatch Bounds in pattern editing

Object > Pattern > Tile Edge Color... picks the colour of the tile edge
(a layer-colour preset or a custom colour), stored in the preference
patternTileEdgeColor and passed to the renderer. Pattern Options gains
Show Swatch Bounds: a dashed outline of the part of the tiling the swatch
repeats (the period of brick and hex tilings).

Commands: prefs.set {patternTileEdgeColor}, pattern.options
{showSwatchBounds}, ui.tileEdgeColor. Model: PatternDef.show_swatch_bounds.

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

crates/engine/src/tests_tileedge.rs

@@ -0,0 +1,63 @@
+//! Pattern editing: the Tile Edge Color preference and Pattern Options' Show Swatch Bounds.
+
+use serde_json::{Value, json};
+use vectorcraft_doc::pattern::PatternDef;
+
+use super::*;
+
+fn run(s: &mut Session, id: &str, p: Value) -> Value {
+    s.execute(id, &p).unwrap_or_else(|e| panic!("{id} {p}: {e}"))
+}
+
+/// A session editing pattern "Dots" made from a 10×10 rectangle.
+fn editing() -> Session {
+    let mut s = Session::new();
+    run(&mut s, "file.new", json!({"width": 200, "height": 200}));
+    run(&mut s, "shape.rectangle", json!({"x": 0, "y": 0, "width": 10, "height": 10}));
+    run(&mut s, "object.pattern.make", json!({"name": "Dots", "width": 20, "height": 20}));
+    s
+}
+
+fn def(s: &Session) -> PatternDef {
+    s.doc().unwrap().doc.pattern("Dots").unwrap().clone()
+}
+
+#[test]
+fn show_swatch_bounds_is_a_pattern_option_that_saves() {
+    let mut s = editing();
+    assert!(!def(&s).show_swatch_bounds);
+    run(&mut s, "pattern.options", json!({"showSwatchBounds": true}));
+    assert!(def(&s).show_swatch_bounds);
+    assert_eq!(run(&mut s, "pattern.list", json!({}))["patterns"][0]["showSwatchBounds"], true);
+    // One undo step.
+    run(&mut s, "edit.undo", json!({}));
+    assert!(!def(&s).show_swatch_bounds);
+    run(&mut s, "edit.redo", json!({}));
+    // Saved with the document; files from before the option load with it off.
+    let bytes = vectorcraft_format::save(&s.doc().unwrap().doc, false);
+    let back = vectorcraft_format::load(&bytes).unwrap();
+    assert_eq!(back.patterns, s.doc().unwrap().doc.patterns);
+    assert!(back.pattern("Dots").unwrap().show_swatch_bounds);
+    let mut old = serde_json::to_value(def(&s)).unwrap();
+    old.as_object_mut().unwrap().remove("showSwatchBounds");
+    assert!(!serde_json::from_value::<PatternDef>(old).unwrap().show_swatch_bounds);
+}
+
+#[test]
+fn tile_edge_color_is_a_preference_that_redraws_pattern_editing() {
+    let mut s = editing();
+    let default = run(&mut s, "prefs.get", json!({"key": "patternTileEdgeColor"}));
+    let [r, g, b] = vectorcraft_doc::LAYER_COLORS[0].1;
+    assert_eq!(default, vectorcraft_color::Color::rgb8(r, g, b).to_hex());
+    let rev = s.doc().unwrap().revision;
+    run(&mut s, "prefs.set", json!({"key": "patternTileEdgeColor", "value": "FF0000"}));
+    assert_eq!(s.prefs.pattern_tile_edge_color, "#ff0000");
+    assert!(s.doc().unwrap().revision > rev, "the canvas redraws the tile edge");
+    assert!(s.execute("prefs.set", &json!({"key": "patternTileEdgeColor", "value": "red"})).is_err());
+    // Saved with the preferences; older preferences get the default.
+    let back: Prefs = serde_json::from_value(s.prefs.to_json()).unwrap();
+    assert_eq!(back.pattern_tile_edge_color, "#ff0000");
+    let mut old = s.prefs.to_json();
+    old.as_object_mut().unwrap().remove("patternTileEdgeColor");
+    assert_eq!(json!(serde_json::from_value::<Prefs>(old).unwrap().pattern_tile_edge_color), default);
+}