Make SolveApp::start honour a command's enabled flag, and disable solid.move inside a sketch (#740)

`SolveApp::start` now honours a command's enabled flag, so shortcuts, the command palette and the control channel can't start a disabled command, and Move is disabled while a sketch is open.

crates/engine/src/cmd/move_in_sketch_tests.rs

@@ -0,0 +1,56 @@
+//! `solid.move` moves bodies, so it has nothing to offer the geometry under the cursor while a
+//! sketch is being edited. It is disabled there, with a reason, and comes back once the sketch
+//! is finished.
+use super::*;
+
+fn cube(s: &mut Session) {
+    s.execute("solid.box", &json!({"length": 20, "width": 20, "height": 20})).unwrap();
+}
+
+fn spec() -> &'static crate::cmd::CommandSpec {
+    crate::find_command("solid.move").unwrap()
+}
+
+#[test]
+fn move_is_disabled_while_a_sketch_is_being_edited_and_says_why() {
+    let mut s = Session::default();
+    cube(&mut s);
+    assert!(spec().info(&s).enabled, "Move is enabled with no sketch open");
+
+    s.execute("sketch.create", &json!({"plane": "XY"})).unwrap();
+    let info = spec().info(&s);
+    assert!(!info.enabled, "Move must be disabled while a sketch is being edited");
+    let why = info.disabled_reason.unwrap_or_default();
+    assert!(why.contains("sketch is being edited"), "the reason must name the sketch: {why}");
+    assert!(why.contains("bodies"), "the reason must say what Move acts on: {why}");
+    assert!(why.contains("Finish Sketch"), "the reason must say the way out: {why}");
+}
+
+#[test]
+fn running_move_in_a_sketch_is_refused_and_changes_nothing() {
+    let mut s = Session::default();
+    cube(&mut s);
+    s.execute("sketch.create", &json!({"plane": "XY"})).unwrap();
+    let features = s.doc.features.len();
+
+    let e = s.execute("solid.move", &json!({"bodies": ["Body1"], "translate": [30, 0, 0]})).unwrap_err();
+    assert!(matches!(e, EngineError::Disabled(ref id, _) if id == "solid.move"), "{e:?}");
+
+    assert_eq!(s.doc.features.len(), features, "a refused command adds no feature");
+    assert!(s.active_sketch.is_some(), "the sketch is still being edited");
+    let bounds = s.model.state().body("Body1").unwrap().mesh().bounds();
+    assert!(bounds.min.dist(Vec3::ZERO) < 1e-6, "the body did not move: {bounds:?}");
+}
+
+#[test]
+fn move_works_again_once_the_sketch_is_finished() {
+    let mut s = Session::default();
+    cube(&mut s);
+    s.execute("sketch.create", &json!({"plane": "XY"})).unwrap();
+    s.execute("sketch.finish", &json!({})).unwrap();
+    assert!(spec().info(&s).enabled, "Move comes back once the sketch is finished");
+
+    s.execute("solid.move", &json!({"bodies": ["Body1"], "translate": [30, 0, 0]})).unwrap();
+    let bounds = s.model.state().body("Body1").unwrap().mesh().bounds();
+    assert!(bounds.min.dist(Vec3::new(30.0, 0.0, 0.0)) < 1e-6, "{bounds:?}");
+}