fix: accept two line picks for sketch coincidence

crates/ui-egui/tests/coincident_lines.rs

@@ -0,0 +1,63 @@
+//! Coincident accepts clicked line bodies as well as explicit sketch points.
+
+use serde_json::json;
+use solvecraft_engine::sketch::ConstraintKind;
+use solvecraft_ui_egui::scenario::Harness;
+
+fn setup() -> Harness {
+    let mut h = Harness::new();
+    h.run(&json!([
+        {"call":"engine.execute","params":{"command":"sketch.create","params":{"plane":"XY"}}},
+        {"call":"engine.execute","params":{"command":"sketch.line","params":{"points":[[10,10],[30,10]],"infer":false,"connect":false}}},
+        {"call":"engine.execute","params":{"command":"sketch.line","params":{"points":[[35,15],[35,40]],"infer":false,"connect":false}}},
+        {"call":"ui.view","params":{"view":"top"}}
+    ]))
+    .unwrap();
+    h
+}
+
+#[test]
+fn clicked_lines_join_closest_endpoints_in_both_orders() {
+    for reverse in [false, true] {
+        let mut h = setup();
+        let before = serde_json::to_value(&h.app.session.doc).unwrap();
+        let undo = h.app.session.undo.len();
+        let picks = if reverse { [[35.0, 27.5], [20.0, 10.0]] } else { [[20.0, 10.0], [35.0, 27.5]] };
+        h.run(
+            &json!([{"start":"sketch.constraint.coincident"}, {"click":{"sketch":picks[0]}}, {"click":{"sketch":picks[1]}}, {"expect":{"errors":0}}]),
+        )
+        .unwrap();
+        assert!(!h.app.status.as_ref().is_some_and(|(_, _, error)| *error));
+        let sk = h.app.session.doc.sketch(h.app.session.active_sketch.unwrap()).unwrap();
+        let a = sk.resolve_point("l1.end").unwrap();
+        let b = sk.resolve_point("l2.start").unwrap();
+        assert!(sk.point(a).unwrap().dist(sk.point(b).unwrap()) < 1e-6);
+        assert!(sk.constraints.iter().any(|c| matches!(c.kind, ConstraintKind::Coincident {p,q} if (p,q)==(a,b) || (p,q)==(b,a))));
+        let fixed_ref = if reverse { "l2.end" } else { "l1.start" };
+        let expected = if reverse { [35.0, 40.0] } else { [10.0, 10.0] };
+        let fixed = sk.point(sk.resolve_point(fixed_ref).unwrap()).unwrap();
+        assert!((fixed.x - expected[0]).abs() < 1e-6 && (fixed.y - expected[1]).abs() < 1e-6);
+        assert_eq!(h.app.session.undo.len(), undo + 1);
+        let after = serde_json::to_value(&h.app.session.doc).unwrap();
+        h.run(&json!([{"call":"engine.execute","params":{"command":"edit.undo","params":{}}}])).unwrap();
+        assert_eq!(serde_json::to_value(&h.app.session.doc).unwrap(), before);
+        h.run(&json!([{"call":"engine.execute","params":{"command":"edit.redo","params":{}}}])).unwrap();
+        assert_eq!(serde_json::to_value(&h.app.session.doc).unwrap(), after);
+    }
+}
+
+#[test]
+fn fixed_line_pair_rejects_without_changing_document_or_history() {
+    let mut h = setup();
+    h.run(&json!([
+        {"call":"engine.execute","params":{"command":"sketch.constraint.fix","params":{"entity":"l1"}}},
+        {"call":"engine.execute","params":{"command":"sketch.constraint.fix","params":{"entity":"l2"}}}
+    ]))
+    .unwrap();
+    let before = serde_json::to_value(&h.app.session.doc).unwrap();
+    let undo = h.app.session.undo.len();
+    h.run(&json!([{"start":"sketch.constraint.coincident"},{"click":{"sketch":[20,10]}},{"click":{"sketch":[35,27.5]}}])).unwrap();
+    assert!(h.app.status.as_ref().is_some_and(|(_, _, error)| *error));
+    assert_eq!(serde_json::to_value(&h.app.session.doc).unwrap(), before);
+    assert_eq!(h.app.session.undo.len(), undo);
+}