--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/SbpOperators/boundaryops/boundary_operator_test.jl	Wed Mar 17 20:34:40 2021 +0100
@@ -0,0 +1,152 @@
+using Test
+
+using Sbplib.LazyTensors
+using Sbplib.SbpOperators
+using Sbplib.Grids
+using Sbplib.RegionIndices
+import Sbplib.SbpOperators.Stencil
+import Sbplib.SbpOperators.BoundaryOperator
+import Sbplib.SbpOperators.boundary_operator
+
+@testset "BoundaryOperator" begin
+    closure_stencil = Stencil((0,2), (2.,1.,3.))
+    g_1D = EquidistantGrid(11, 0.0, 1.0)
+    g_2D = EquidistantGrid((11,15), (0.0, 0.0), (1.0,1.0))
+
+    @testset "Constructors" begin
+        @testset "1D" begin
+            op_l = BoundaryOperator{Lower}(closure_stencil,size(g_1D)[1])
+            @test op_l == BoundaryOperator(g_1D,closure_stencil,Lower())
+            @test op_l == boundary_operator(g_1D,closure_stencil,CartesianBoundary{1,Lower}())
+            @test op_l isa TensorMapping{T,0,1} where T
+
+            op_r = BoundaryOperator{Upper}(closure_stencil,size(g_1D)[1])
+            @test op_r == BoundaryOperator(g_1D,closure_stencil,Upper())
+            @test op_r == boundary_operator(g_1D,closure_stencil,CartesianBoundary{1,Upper}())
+            @test op_r isa TensorMapping{T,0,1} where T
+        end
+
+        @testset "2D" begin
+            e_w = boundary_operator(g_2D,closure_stencil,CartesianBoundary{1,Upper}())
+            @test e_w isa InflatedTensorMapping
+            @test e_w isa TensorMapping{T,1,2} where T
+        end
+    end
+
+    op_l = boundary_operator(g_1D, closure_stencil, CartesianBoundary{1,Lower}())
+    op_r = boundary_operator(g_1D, closure_stencil, CartesianBoundary{1,Upper}())
+
+    op_w = boundary_operator(g_2D, closure_stencil, CartesianBoundary{1,Lower}())
+    op_e = boundary_operator(g_2D, closure_stencil, CartesianBoundary{1,Upper}())
+    op_s = boundary_operator(g_2D, closure_stencil, CartesianBoundary{2,Lower}())
+    op_n = boundary_operator(g_2D, closure_stencil, CartesianBoundary{2,Upper}())
+
+    @testset "Sizes" begin
+        @testset "1D" begin
+            @test domain_size(op_l) == (11,)
+            @test domain_size(op_r) == (11,)
+
+            @test range_size(op_l) == ()
+            @test range_size(op_r) == ()
+        end
+
+        @testset "2D" begin
+            @test domain_size(op_w) == (11,15)
+            @test domain_size(op_e) == (11,15)
+            @test domain_size(op_s) == (11,15)
+            @test domain_size(op_n) == (11,15)
+
+            @test range_size(op_w) == (15,)
+            @test range_size(op_e) == (15,)
+            @test range_size(op_s) == (11,)
+            @test range_size(op_n) == (11,)
+        end
+    end
+
+    @testset "Application" begin
+        @testset "1D" begin
+            v = evalOn(g_1D,x->1+x^2)
+            u = fill(3.124)
+            @test (op_l*v)[] == 2*v[1] + v[2] + 3*v[3]
+            @test (op_r*v)[] == 2*v[end] + v[end-1] + 3*v[end-2]
+            @test (op_r*v)[1] == 2*v[end] + v[end-1] + 3*v[end-2]
+            @test op_l'*u == [2*u[]; u[]; 3*u[]; zeros(8)]
+            @test op_r'*u == [zeros(8); 3*u[]; u[]; 2*u[]]
+        end
+
+        @testset "2D" begin
+            v = rand(size(g_2D)...)
+            u = fill(3.124)
+            @test op_w*v ≈ 2*v[1,:] + v[2,:] + 3*v[3,:] rtol = 1e-14
+            @test op_e*v ≈ 2*v[end,:] + v[end-1,:] + 3*v[end-2,:] rtol = 1e-14
+            @test op_s*v ≈ 2*v[:,1] + v[:,2] + 3*v[:,3] rtol = 1e-14
+            @test op_n*v ≈ 2*v[:,end] + v[:,end-1] + 3*v[:,end-2] rtol = 1e-14
+
+
+            g_x = rand(size(g_2D)[1])
+            g_y = rand(size(g_2D)[2])
+
+            G_w = zeros(Float64, size(g_2D)...)
+            G_w[1,:] = 2*g_y
+            G_w[2,:] = g_y
+            G_w[3,:] = 3*g_y
+
+            G_e = zeros(Float64, size(g_2D)...)
+            G_e[end,:] = 2*g_y
+            G_e[end-1,:] = g_y
+            G_e[end-2,:] = 3*g_y
+
+            G_s = zeros(Float64, size(g_2D)...)
+            G_s[:,1] = 2*g_x
+            G_s[:,2] = g_x
+            G_s[:,3] = 3*g_x
+
+            G_n = zeros(Float64, size(g_2D)...)
+            G_n[:,end] = 2*g_x
+            G_n[:,end-1] = g_x
+            G_n[:,end-2] = 3*g_x
+
+            @test op_w'*g_y == G_w
+            @test op_e'*g_y == G_e
+            @test op_s'*g_x == G_s
+            @test op_n'*g_x == G_n
+       end
+
+       @testset "Regions" begin
+            u = fill(3.124)
+            @test (op_l'*u)[Index(1,Lower)] == 2*u[]
+            @test (op_l'*u)[Index(2,Lower)] == u[]
+            @test (op_l'*u)[Index(6,Interior)] == 0
+            @test (op_l'*u)[Index(10,Upper)] == 0
+            @test (op_l'*u)[Index(11,Upper)] == 0
+
+            @test (op_r'*u)[Index(1,Lower)] == 0
+            @test (op_r'*u)[Index(2,Lower)] == 0
+            @test (op_r'*u)[Index(6,Interior)] == 0
+            @test (op_r'*u)[Index(10,Upper)] == u[]
+            @test (op_r'*u)[Index(11,Upper)] == 2*u[]
+       end
+    end
+
+    @testset "Inferred" begin
+        v = ones(Float64, 11)
+        u = fill(1.)
+
+        @inferred apply(op_l, v)
+        @inferred apply(op_r, v)
+
+        @inferred apply_transpose(op_l, u, 4)
+        @inferred apply_transpose(op_l, u, Index(1,Lower))
+        @inferred apply_transpose(op_l, u, Index(2,Lower))
+        @inferred apply_transpose(op_l, u, Index(6,Interior))
+        @inferred apply_transpose(op_l, u, Index(10,Upper))
+        @inferred apply_transpose(op_l, u, Index(11,Upper))
+
+        @inferred apply_transpose(op_r, u, 4)
+        @inferred apply_transpose(op_r, u, Index(1,Lower))
+        @inferred apply_transpose(op_r, u, Index(2,Lower))
+        @inferred apply_transpose(op_r, u, Index(6,Interior))
+        @inferred apply_transpose(op_r, u, Index(10,Upper))
+        @inferred apply_transpose(op_r, u, Index(11,Upper))
+    end
+end