diff --git a/tests/reshape_test.py b/tests/reshape_test.py
index 6d32e90..f04b273 100644
--- a/tests/reshape_test.py
+++ b/tests/reshape_test.py
@@ -15,3 +15,74 @@ def test_reshape_consistency(arrow: tuple[bool, ...], plan_range: tuple[int, int
     b = a.reshape(plan)
     c = b.reshape(a.edges)
     assert torch.allclose(a.tensor, c.tensor)
+
+
+def test_reshape_merging_dimension_mismatch_edges() -> None:
+    arrow = (True, True, True)
+    edges = ((2, 2), (8, 8), (2, 2))
+    a = GrassmannTensor(arrow, edges, torch.randn([4, 16, 4]))
+    _ = a.reshape((64, -1))
+    _ = a.reshape((-1, 64))
+    with pytest.raises(AssertionError, match="Dimension mismatch with edges"):
+        _ = a.reshape((16, -1, -1))
+
+
+def test_reshape_merging_new_shape_exceeds() -> None:
+    arrow = (True,)
+    edges = ((2, 2),)
+    a = GrassmannTensor(arrow, edges, torch.randn([4]))
+    with pytest.raises(AssertionError, match="exceeds tensor dimensions"):
+        _ = a.reshape((16, -1))
+
+
+def test_reshape_merging_even_odd_mismatch() -> None:
+    arrow = (True, True, True)
+    edges = ((2, 2), (8, 8), (2, 2))
+    a = GrassmannTensor(arrow, edges, torch.randn([4, 16, 4]))
+    _ = a.reshape(((32, 32), (2, 2)))
+    _ = a.reshape(((2, 2), (32, 32)))
+    with pytest.raises(AssertionError, match="New even and odd number mismatch during merging"):
+        _ = a.reshape(((30, 34), (2, 2)))
+
+
+def test_reshape_merging_mixed_arrows() -> None:
+    arrow = (True, False, True)
+    edges = ((2, 2), (2, 2), (2, 2))
+    a = GrassmannTensor(arrow, edges, torch.randn([4, 4, 4]))
+    with pytest.raises(AssertionError, match="Cannot merge edges with different arrows"):
+        _ = a.reshape((64,))
+
+
+def test_reshape_splitting_shape_type() -> None:
+    arrow = (True,)
+    edges = ((8, 8),)
+    a = GrassmannTensor(arrow, edges, torch.randn([16]))
+    _ = a.reshape(((2, 2), (2, 2)))
+    with pytest.raises(AssertionError, match="New shape must be a pair when splitting"):
+        _ = a.reshape((2, (2, 2)))
+
+
+def test_reshape_splitting_dimension_mismatch_edges() -> None:
+    arrow = (True,)
+    edges = ((8, 8),)
+    a = GrassmannTensor(arrow, edges, torch.randn([16]))
+    _ = a.reshape(((2, 2), (2, 2)))
+    with pytest.raises(AssertionError, match="Dimension mismatch with edges"):
+        _ = a.reshape(((4, 4), (2, 2)))
+
+
+def test_reshape_splitting_shape_exceeds() -> None:
+    arrow = (False,)
+    edges = ((2, 2),)
+    a = GrassmannTensor(arrow, edges, torch.randn([4]))
+    with pytest.raises(AssertionError, match="exceeds specified dimensions"):
+        _ = a.reshape(((3, 0), (0, 1)))
+
+
+def test_reshape_splitting_even_odd_mismatch() -> None:
+    arrow = (False,)
+    edges = ((6, 10),)
+    a = GrassmannTensor(arrow, edges, torch.randn([16]))
+    _ = a.reshape(((1, 3), (3, 1)))
+    with pytest.raises(AssertionError, match="New even and odd number mismatch during splitting"):
+        _ = a.reshape(((2, 2), (2, 2)))