diff --git a/crates/oxide_kernel/src/shape_forge.rs b/crates/oxide_kernel/src/shape_forge.rs
index 211c8c2d..09f4a1c2 100644
--- a/crates/oxide_kernel/src/shape_forge.rs
+++ b/crates/oxide_kernel/src/shape_forge.rs
@@ -245,86 +245,6 @@ mod tests {
     use super::*;
     use std::sync::Barrier;
 
-    #[test]
-    fn empty_shape_exists() {
-        let forge = ShapeForge::new();
-        let s = forge.get_shape(EMPTY_SHAPE_ID);
-        assert!(s.is_some());
-        let s = s.unwrap();
-        assert_eq!(s.id, EMPTY_SHAPE_ID);
-        assert!(s.parent.is_none());
-        assert_eq!(s.depth, 0);
-    }
-
-    #[test]
-    fn make_shape_creates_new_id() {
-        let forge = ShapeForge::new();
-        let key: StringIndex = 1_000_000;
-        let s1 = forge.make_shape(EMPTY_SHAPE_ID, key);
-        assert!(s1 > EMPTY_SHAPE_ID);
-        let shape = forge.get_shape(s1).unwrap();
-        assert_eq!(shape.property_name, key);
-        assert_eq!(shape.parent, Some(EMPTY_SHAPE_ID));
-        assert_eq!(shape.depth, 1);
-    }
-
-    #[test]
-    fn hash_cons_returns_same_id() {
-        let forge = ShapeForge::new();
-        let key: StringIndex = 1_000_001;
-        let a = forge.make_shape(EMPTY_SHAPE_ID, key);
-        let b = forge.make_shape(EMPTY_SHAPE_ID, key);
-        assert_eq!(a, b);
-    }
-
-    #[test]
-    fn different_props_different_ids() {
-        let forge = ShapeForge::new();
-        let a = forge.make_shape(EMPTY_SHAPE_ID, 1_000_002);
-        let b = forge.make_shape(EMPTY_SHAPE_ID, 1_000_003);
-        assert_ne!(a, b);
-    }
-
-    #[test]
-    fn chain_of_three() {
-        let forge = ShapeForge::new();
-        let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_010);
-        let s2 = forge.make_shape(s1, 1_000_020);
-        let s3 = forge.make_shape(s2, 1_000_030);
-
-        assert_eq!(forge.shape_prop_count(s3), 3);
-
-        assert_eq!(forge.lookup_position(s3, 1_000_030), Some(2));
-        assert_eq!(forge.lookup_position(s3, 1_000_020), Some(1));
-        assert_eq!(forge.lookup_position(s3, 1_000_010), Some(0));
-        assert_eq!(forge.lookup_position(s3, 99), None);
-    }
-
-    #[test]
-    fn lookup_position_cached_second_call() {
-        let forge = ShapeForge::new();
-        let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_010);
-        let s2 = forge.make_shape(s1, 1_000_020);
-        let s3 = forge.make_shape(s2, 1_000_030);
-
-        // 首次调用填充缓存。
-        assert_eq!(forge.lookup_position(s3, 1_000_020), Some(1));
-        // 二次调用命中缓存（验证无回归）。
-        assert_eq!(forge.lookup_position(s3, 1_000_020), Some(1));
-        assert_eq!(forge.lookup_position(s3, 1_000_030), Some(2));
-        assert_eq!(forge.lookup_position(s3, 1_000_030), Some(2));
-    }
-
-    #[test]
-    fn clear_transient_clears_positions() {
-        let forge = ShapeForge::new();
-        let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_010);
-        assert_eq!(forge.lookup_position(s1, 1_000_010), Some(0));
-        forge.clear_transient();
-        // 清理后只剩 EMPTY_SHAPE，其余全部移除。
-        assert_eq!(forge.shapes.read().unwrap().len(), 1);
-    }
-
     /// overflow 态复位钉：曾触发 overflow 后清空，overflow 标志与映射须一并清空，
     /// 后续 make_shape 从新空间取小 id（而非旧 overflow 映射 id）。
     #[test]
@@ -342,78 +262,6 @@ mod tests {
         assert_eq!(id, 2);
     }
 
-    #[test]
-    fn two_branches_share_ancestor() {
-        let forge = ShapeForge::new();
-        let base = forge.make_shape(EMPTY_SHAPE_ID, 1_000_040);
-        let branch_a = forge.make_shape(base, 1_000_050);
-        let branch_b = forge.make_shape(base, 1_000_060);
-        assert_ne!(branch_a, branch_b);
-        let a_shape = forge.get_shape(branch_a).unwrap();
-        let b_shape = forge.get_shape(branch_b).unwrap();
-        assert_eq!(a_shape.parent, Some(base));
-        assert_eq!(b_shape.parent, Some(base));
-    }
-
-    #[test]
-    fn edge_same_structure_different_names() {
-        let forge = ShapeForge::new();
-        let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_070);
-        let s2 = forge.make_shape(s1, 1_000_080);
-        let s3 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_090);
-        let s4 = forge.make_shape(s3, 1_000_100);
-        assert_ne!(s1, s3);
-        assert_ne!(s2, s4);
-        assert_eq!(forge.lookup_position(s2, 1_000_070), Some(0));
-        assert_eq!(forge.lookup_position(s4, 1_000_090), Some(0));
-    }
-
-    #[test]
-    fn concurrent_make_same_key() {
-        let forge = Arc::new(ShapeForge::new());
-        let key: StringIndex = 1_000_200;
-        let barrier = Arc::new(Barrier::new(2));
-
-        let f1 = Arc::clone(&forge);
-        let b1 = Arc::clone(&barrier);
-        let h1 = std::thread::spawn(move || {
-            b1.wait();
-            f1.make_shape(EMPTY_SHAPE_ID, key)
-        });
-
-        let f2 = Arc::clone(&forge);
-        let b2 = Arc::clone(&barrier);
-        let h2 = std::thread::spawn(move || {
-            b2.wait();
-            f2.make_shape(EMPTY_SHAPE_ID, key)
-        });
-
-        let id1 = h1.join().unwrap();
-        let id2 = h2.join().unwrap();
-        assert_eq!(id1, id2);
-        assert!(id1 > EMPTY_SHAPE_ID);
-    }
-
-    #[test]
-    fn has_property_works() {
-        let forge = ShapeForge::new();
-        let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_300);
-        let s2 = forge.make_shape(s1, 1_000_310);
-        assert!(forge.has_property(s2, 1_000_300));
-        assert!(forge.has_property(s2, 1_000_310));
-        assert!(!forge.has_property(s2, 99));
-    }
-
-    #[test]
-    fn private_band_keys_are_shape_properties() {
-        let forge = ShapeForge::new();
-        let private_key = oxide_types::private_key::make_private_name_id(12);
-        let shape = forge.make_shape(EMPTY_SHAPE_ID, private_key);
-        assert!(oxide_types::private_key::is_private_name_key(private_key));
-        assert!(forge.has_property(shape, private_key));
-        assert_eq!(forge.lookup_position(shape, private_key), Some(0));
-    }
-
     #[test]
     #[cfg_attr(debug_assertions, should_panic(expected = "exceeds 24-bit"))]
     fn overflow_debug_assert_fires() {
diff --git a/crates/oxide_kernel/tests/shape_forge_tests.rs b/crates/oxide_kernel/tests/shape_forge_tests.rs
new file mode 100644
index 00000000..2731fb92
--- /dev/null
+++ b/crates/oxide_kernel/tests/shape_forge_tests.rs
@@ -0,0 +1,153 @@
+use oxide_kernel::shape_forge::{ShapeForge, StringIndex, EMPTY_SHAPE_ID};
+use std::sync::{Arc, Barrier};
+
+#[test]
+fn empty_shape_exists() {
+    let forge = ShapeForge::new();
+    let s = forge.get_shape(EMPTY_SHAPE_ID);
+    assert!(s.is_some());
+    let s = s.unwrap();
+    assert_eq!(s.id, EMPTY_SHAPE_ID);
+    assert!(s.parent.is_none());
+    assert_eq!(s.depth, 0);
+}
+
+#[test]
+fn make_shape_creates_new_id() {
+    let forge = ShapeForge::new();
+    let key: StringIndex = 1_000_000;
+    let s1 = forge.make_shape(EMPTY_SHAPE_ID, key);
+    assert!(s1 > EMPTY_SHAPE_ID);
+    let shape = forge.get_shape(s1).unwrap();
+    assert_eq!(shape.property_name, key);
+    assert_eq!(shape.parent, Some(EMPTY_SHAPE_ID));
+    assert_eq!(shape.depth, 1);
+}
+
+#[test]
+fn hash_cons_returns_same_id() {
+    let forge = ShapeForge::new();
+    let key: StringIndex = 1_000_001;
+    let a = forge.make_shape(EMPTY_SHAPE_ID, key);
+    let b = forge.make_shape(EMPTY_SHAPE_ID, key);
+    assert_eq!(a, b);
+}
+
+#[test]
+fn different_props_different_ids() {
+    let forge = ShapeForge::new();
+    let a = forge.make_shape(EMPTY_SHAPE_ID, 1_000_002);
+    let b = forge.make_shape(EMPTY_SHAPE_ID, 1_000_003);
+    assert_ne!(a, b);
+}
+
+#[test]
+fn chain_of_three() {
+    let forge = ShapeForge::new();
+    let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_010);
+    let s2 = forge.make_shape(s1, 1_000_020);
+    let s3 = forge.make_shape(s2, 1_000_030);
+
+    assert_eq!(forge.shape_prop_count(s3), 3);
+
+    assert_eq!(forge.lookup_position(s3, 1_000_030), Some(2));
+    assert_eq!(forge.lookup_position(s3, 1_000_020), Some(1));
+    assert_eq!(forge.lookup_position(s3, 1_000_010), Some(0));
+    assert_eq!(forge.lookup_position(s3, 99), None);
+}
+
+#[test]
+fn lookup_position_cached_second_call() {
+    let forge = ShapeForge::new();
+    let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_010);
+    let s2 = forge.make_shape(s1, 1_000_020);
+    let s3 = forge.make_shape(s2, 1_000_030);
+
+    // 首次调用填充缓存。
+    assert_eq!(forge.lookup_position(s3, 1_000_020), Some(1));
+    // 二次调用命中缓存（验证无回归）。
+    assert_eq!(forge.lookup_position(s3, 1_000_020), Some(1));
+    assert_eq!(forge.lookup_position(s3, 1_000_030), Some(2));
+    assert_eq!(forge.lookup_position(s3, 1_000_030), Some(2));
+}
+
+#[test]
+fn clear_transient_clears_positions() {
+    let forge = ShapeForge::new();
+    let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_010);
+    assert_eq!(forge.lookup_position(s1, 1_000_010), Some(0));
+    forge.clear_transient();
+    // 清理后只剩 EMPTY_SHAPE，其余全部移除。
+    assert_eq!(forge.len(), 1);
+}
+#[test]
+fn two_branches_share_ancestor() {
+    let forge = ShapeForge::new();
+    let base = forge.make_shape(EMPTY_SHAPE_ID, 1_000_040);
+    let branch_a = forge.make_shape(base, 1_000_050);
+    let branch_b = forge.make_shape(base, 1_000_060);
+    assert_ne!(branch_a, branch_b);
+    let a_shape = forge.get_shape(branch_a).unwrap();
+    let b_shape = forge.get_shape(branch_b).unwrap();
+    assert_eq!(a_shape.parent, Some(base));
+    assert_eq!(b_shape.parent, Some(base));
+}
+
+#[test]
+fn edge_same_structure_different_names() {
+    let forge = ShapeForge::new();
+    let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_070);
+    let s2 = forge.make_shape(s1, 1_000_080);
+    let s3 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_090);
+    let s4 = forge.make_shape(s3, 1_000_100);
+    assert_ne!(s1, s3);
+    assert_ne!(s2, s4);
+    assert_eq!(forge.lookup_position(s2, 1_000_070), Some(0));
+    assert_eq!(forge.lookup_position(s4, 1_000_090), Some(0));
+}
+
+#[test]
+fn concurrent_make_same_key() {
+    let forge = Arc::new(ShapeForge::new());
+    let key: StringIndex = 1_000_200;
+    let barrier = Arc::new(Barrier::new(2));
+
+    let f1 = Arc::clone(&forge);
+    let b1 = Arc::clone(&barrier);
+    let h1 = std::thread::spawn(move || {
+        b1.wait();
+        f1.make_shape(EMPTY_SHAPE_ID, key)
+    });
+
+    let f2 = Arc::clone(&forge);
+    let b2 = Arc::clone(&barrier);
+    let h2 = std::thread::spawn(move || {
+        b2.wait();
+        f2.make_shape(EMPTY_SHAPE_ID, key)
+    });
+
+    let id1 = h1.join().unwrap();
+    let id2 = h2.join().unwrap();
+    assert_eq!(id1, id2);
+    assert!(id1 > EMPTY_SHAPE_ID);
+}
+
+#[test]
+fn has_property_works() {
+    let forge = ShapeForge::new();
+    let s1 = forge.make_shape(EMPTY_SHAPE_ID, 1_000_300);
+    let s2 = forge.make_shape(s1, 1_000_310);
+    assert!(forge.has_property(s2, 1_000_300));
+    assert!(forge.has_property(s2, 1_000_310));
+    assert!(!forge.has_property(s2, 99));
+}
+
+#[test]
+fn private_band_keys_are_shape_properties() {
+    let forge = ShapeForge::new();
+    let private_key = oxide_types::private_key::make_private_name_id(12);
+    let shape = forge.make_shape(EMPTY_SHAPE_ID, private_key);
+    assert!(oxide_types::private_key::is_private_name_key(private_key));
+    assert!(forge.has_property(shape, private_key));
+    assert_eq!(forge.lookup_position(shape, private_key), Some(0));
+}