Surface walls named after their sketch curves (#757) (#850)

Each wall of a surface built from sketch curves (Surface Extrude, Revolve, Sweep and Loft) is now named after the curve it comes from, exactly rather than from geometry, so references to those faces survive edits.

crates/engine/src/cmd/surface.rs

@@ -544,6 +544,47 @@ mod tests {
         );
     }
 
+    /// Each wall of a surface built from sketch curves is named after the curve it comes from,
+    /// exactly (not from geometry): extrude, revolve, sweep and loft.
+    #[test]
+    fn surface_walls_are_named_after_their_curves() {
+        let mut s = Session::default();
+        run(&mut s, "construct.plane.offset", json!({"base": "XY", "offset": 5, "name": "Mid"}));
+        run(&mut s, "sketch.create", json!({"plane": "XY", "name": "S"}));
+        run(&mut s, "sketch.line", json!({"points": [[3, 0], [3, 4]], "ids": ["l1"]}));
+        run(&mut s, "sketch.line", json!({"points": [[3, 4], [6, 4]], "ids": ["l2"]}));
+        run(&mut s, "sketch.finish", json!({}));
+        run(&mut s, "sketch.create", json!({"plane": "XZ", "name": "P"}));
+        run(&mut s, "sketch.line", json!({"points": [[0, 0], [0, 5]], "ids": ["up"]}));
+        run(&mut s, "sketch.finish", json!({}));
+        run(&mut s, "sketch.create", json!({"plane": "Mid", "name": "T"}));
+        run(&mut s, "sketch.line", json!({"points": [[3, 0], [3, 4]], "ids": ["m1"]}));
+        run(&mut s, "sketch.line", json!({"points": [[3, 4], [6, 4]], "ids": ["m2"]}));
+        run(&mut s, "sketch.finish", json!({}));
+        let made = [
+            ("surface.extrude", json!({"sketch": "S", "curves": ["l1", "l2"], "distance": 3, "body_name": "E"})),
+            ("surface.revolve", json!({"sketch": "S", "curves": ["l1", "l2"], "axis": "y", "angle": "90 deg", "body_name": "R"})),
+            ("surface.sweep", json!({"sketch": "S", "curves": ["l1", "l2"], "path_sketch": "P", "path": ["up"], "body_name": "W"})),
+            (
+                "surface.loft",
+                json!({"sections": [{"sketch": "S", "curves": ["l1", "l2"]}, {"sketch": "T", "curves": ["m1", "m2"]}], "body_name": "L"}),
+            ),
+        ];
+        for (cmd, p) in made {
+            let body = p["body_name"].as_str().unwrap().to_string();
+            run(&mut s, cmd, p);
+            let fid = s.doc.features.last().unwrap().id;
+            let st = s.model.state();
+            let b = st.body(&body).unwrap();
+            let names = solidcraft_doc::naming::face_names(b);
+            for curve in ["l1", "l2"] {
+                let want = format!("F{fid}:side:{curve}");
+                let i = names.iter().position(|n| n.starts_with(&want)).unwrap_or_else(|| panic!("{cmd}: no face named {want}: {names:?}"));
+                assert!(solidcraft_doc::naming::face_name_exact(b, i), "{cmd}: {want} is named from geometry");
+            }
+        }
+    }
+
     /// The planned surface commands are registered but refuse to run: disabled with the
     /// issue that tracks them, an error (never a panic) from every caller, and the design left
     /// as it was.