--- a/test/Grids/tensor_grid_test.jl	Tue Jun 11 21:43:01 2024 +0200
+++ b/test/Grids/tensor_grid_test.jl	Wed Jun 19 11:16:42 2024 +0200
@@ -175,14 +175,22 @@
         g₂ = EquidistantGrid(range(2,3,length=6))
         g₄ = ZeroDimGrid(@SVector[1,2])
 
-        @test boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Lower}()) == (1,:)
-        @test boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Upper}()) == (11,:)
-        @test boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{2, Lower}()) == (:,1)
-        @test boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{2, Upper}()) == (:,6)
-        @test boundary_indices(TensorGrid(g₁, g₄), TensorGridBoundary{1, Lower}()) == (1,)
-        @test boundary_indices(TensorGrid(g₁, g₄), TensorGridBoundary{1, Upper}()) == (11,)
-        @test boundary_indices(TensorGrid(g₄,g₁), TensorGridBoundary{2, Lower}()) == (1,)
-        @test boundary_indices(TensorGrid(g₄,g₁), TensorGridBoundary{2, Upper}()) == (11,)
+        @test iterate(boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Lower}()))
+
+        gf = reshape(1:(11*6),11,6)
+        @test gf[boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Lower}()))] == gf[1,:]
+        @test gf[boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Upper}()))] == gf[11,:]
+        @test gf[boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{2, Lower}()))] == gf[:,1]
+        @test gf[boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{2, Upper}()))] == gf[:,6]
+
+        @test collect(boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Lower}())) == [(1,i) for i ∈ 1:6]
+        @test collect(boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{1, Upper}())) == [(11,i) for i ∈ 1:6]
+        @test collect(boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{2, Lower}())) == [(i,1) for i ∈ 1:11]
+        @test collect(boundary_indices(TensorGrid(g₁, g₂), TensorGridBoundary{2, Upper}())) == [(i,6) for i ∈ 1:11]
+        @test collect(boundary_indices(TensorGrid(g₁, g₄), TensorGridBoundary{1, Lower}())) == [(1,)]
+        @test collect(boundary_indices(TensorGrid(g₁, g₄), TensorGridBoundary{1, Upper}())) == [(11,)]
+        @test collect(boundary_indices(TensorGrid(g₄,g₁), TensorGridBoundary{2, Lower}())) == [(1,)]
+        @test collect(boundary_indices(TensorGrid(g₄,g₁), TensorGridBoundary{2, Upper}())) == [(11,)]
     end
 end