--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/BoundaryConditions/boundary_condition_test.jl	Wed Dec 07 21:39:07 2022 +0100
@@ -0,0 +1,99 @@
+using Test
+
+using Sbplib.BoundaryConditions
+using Sbplib.Grids
+
+grid_1D = EquidistantGrid(11, 0.0, 1.0)
+grid_2D = EquidistantGrid((11,15), (0.0, 0.0), (1.0,1.0))
+grid_3D = EquidistantGrid((11,15,13), (0.0, 0.0, 0.0), (1.0,1.0, 1.0))
+(id_l,_) = boundary_identifiers(grid_1D)
+(_,_,_,id_n) = boundary_identifiers(grid_2D)
+(_,_,_,_,id_b,_) = boundary_identifiers(grid_3D)
+
+@testset "BoundaryData" begin
+    
+    @testset "ConstantBoundaryData" begin
+        c = float(pi)
+        @test ConstantBoundaryData(c) isa BoundaryData
+        g_1D = discretize(ConstantBoundaryData(c),boundary_grid(grid_1D, id_l))
+        g_2D = discretize(ConstantBoundaryData(c),boundary_grid(grid_2D, id_n))
+        @test g_1D isa Function
+        @test g_2D isa Function
+        @test g_1D(0.) == fill(c)
+        @test g_2D(2.) == c*ones(11)
+        @test_throws MethodError g_1D(0.,0.)
+        @test_throws MethodError g_2D(0.,0.)
+    end
+
+    @testset "TimeDependentBoundaryData" begin
+        f(t) = 1. /(t+0.1)
+        @test TimeDependentBoundaryData(f) isa BoundaryData
+        g_1D = discretize(TimeDependentBoundaryData(f),boundary_grid(grid_1D, id_l))
+        g_2D = discretize(TimeDependentBoundaryData(f),boundary_grid(grid_2D, id_n))
+        @test g_1D isa Function
+        @test g_2D isa Function
+        @test g_1D(0.) == f(0.)*fill(1)
+        @test g_2D(2.) == f(2.)*ones(11)
+        @test_throws MethodError g_1D(0.,0.)
+        @test_throws MethodError g_2D(0.,0.)
+    end
+    
+    #TBD: Is it reasoanble to have SpaceDependentBoundaryData for 1D-grids? It would then be a constant
+    #     which then may be represented by ConstantBoundaryData.
+    @testset "SpaceDependentBoundaryData" begin
+        f0() = 2
+        f1(x) = x.^2
+        f2(x,y) = x.^2 - y
+        @test SpaceDependentBoundaryData(f1) isa BoundaryData
+        g_1D = discretize(SpaceDependentBoundaryData(f0),boundary_grid(grid_1D, id_l))
+        g_2D = discretize(SpaceDependentBoundaryData(f1),boundary_grid(grid_2D, id_n))
+        g_3D = discretize(SpaceDependentBoundaryData(f2),boundary_grid(grid_3D, id_n))
+        @test g_1D isa Function
+        @test g_2D isa Function
+        @test g_3D isa Function
+        @test_broken g_1D(1.) == fill(f0()) # Does not work since evalOn for f0 returns ().
+        @test g_2D(2.) ≈ f1.(range(0., 1., 11)) rtol=1e-14
+        @test g_3D(0.) ≈ evalOn(boundary_grid(grid_3D, id_n),f2) rtol=1e-14
+        @test_throws MethodError g_1D(0.,0.)
+        @test_throws MethodError g_2D(0.,0.)
+        @test_throws MethodError g_3D(0.,0.)
+    end
+    
+    # TBD: Include tests for 1D-grids? See TBD above
+    @testset "SpaceTimeDependentBoundaryData" begin
+        fx1(x) = x.^2
+        fx2(x,y) = x.^2 - y
+        ft(t) = exp(t)
+        ftx1(t,x) = ft(t)*fx1(x)
+        ftx2(t,x,y) = ft(t)*fx2(x,y)
+        @test SpaceTimeDependentBoundaryData(ftx1) isa BoundaryData
+        g_2D = discretize(SpaceTimeDependentBoundaryData(ftx1),boundary_grid(grid_2D, id_n))
+        g_3D = discretize(SpaceTimeDependentBoundaryData(ftx2),boundary_grid(grid_3D, id_b))
+        @test g_2D isa Function
+        @test g_3D isa Function
+        @test g_2D(2.) ≈ ft(2.)*fx1.(range(0., 1., 11)) rtol=1e-14
+        @test g_3D(3.14) ≈ ft(3.14)*evalOn(boundary_grid(grid_3D, id_b),fx2) rtol=1e-14
+        @test_throws MethodError g_2D(0.,0.)
+        @test_throws MethodError g_3D(0.,0.)
+    end
+
+    @testset "ZeroBoundaryData" begin
+        @test ZeroBoundaryData() isa BoundaryData
+        g_2D = discretize(ZeroBoundaryData(), boundary_grid(grid_2D, id_n))
+        g_3D = discretize(ZeroBoundaryData(), boundary_grid(grid_3D, id_b))
+        @test g_2D isa Function
+        @test g_3D isa Function
+        @test g_2D(2.) ≈ 0.0*range(0., 1., 11) rtol=1e-14
+        f(x,y) = 0
+        @test g_3D(3.14) ≈ 0.0*evalOn(boundary_grid(grid_3D, id_b), f) rtol=1e-14
+        @test_throws MethodError g_2D(0.,0.)
+        @test_throws MethodError g_3D(0.,0.)
+    end
+end
+
+@testset "BoundaryCondition" begin
+    g = ConstantBoundaryData(1.0)
+    NeumannCondition(g,id_n) isa BoundaryCondition{ConstantBoundaryData}
+    DirichletCondition(g,id_n) isa BoundaryCondition{ConstantBoundaryData}
+    @test data(NeumannCondition(g,id_n)) == g
+end