--- a/test/Grids/grid_test.jl	Fri Feb 24 21:54:39 2023 +0100
+++ b/test/Grids/grid_test.jl	Sat Feb 25 22:22:50 2023 +0100
@@ -1,15 +1,42 @@
+using Test
 using Sbplib.Grids
-using Test
+using Sbplib.LazyTensors
+using StaticArrays
 
 @testset "Grid" begin
-    @test_broken false
+    struct DummyGrid{T,D} <: Grid{T,D} end
+
+    @test eltype(DummyGrid{Int, 2}) == Int
+    @test eltype(DummyGrid{Int, 2}()) == Int
+
+    @test ndims(DummyGrid{Int, 2}()) == 2
+    @test dims(DummyGrid{Int, 2}()) == 1:2
 end
 
 @testset "eval_on" begin
+    @test eval_on(ZeroDimGrid(@SVector[1.,2.]), x̄->x̄[1]+x̄[2]) isa LazyArray
+    @test eval_on(ZeroDimGrid(@SVector[1.,2.]), x̄->x̄[1]+x̄[2]) == fill(3.)
+    @test eval_on(ZeroDimGrid(@SVector[3.,2.]), x̄->x̄[1]+x̄[2]) == fill(5.)
+
+    @test eval_on(EquidistantGrid(range(0,1,length=4)), x->2x) isa LazyArray
+    @test eval_on(EquidistantGrid(range(0,1,length=4)), x->2x) == 2 .* range(0,1,length=4)
+
+
     g = equidistant_grid((5,3), (0.0,0.0), (2.0,1.0))
 
-    @test_broken eval_on(g, (x,y) -> 0.) isa LazyArray
-    @test_broken eval_on(g, (x,y) -> 0.) == fill(0., (5,3))
+
+    # Splat for only one dim, controllef by type specification in function.
+
+    @test eval_on(g, x̄ -> 0.) isa LazyArray
+    @test eval_on(g, x̄ -> 0.) == fill(0., (5,3))
+
+    @test eval_on(g, x̄ -> sin(x̄[1])*cos(x̄[2])) == map(x̄->sin(x̄[1])*cos(x̄[2]), g)
+
+    # Vector valued function
+    @test eval_on(g, x̄ -> @SVector[x̄[2], x̄[1]]) isa LazyArray{SVector{2,Float64}}
+    @test eval_on(g, x̄ -> @SVector[x̄[2], x̄[1]]) == map(x̄ -> @SVector[x̄[2], x̄[1]], g)
+
+
 
     f(x,y) = sin(x)*cos(y)
     @test_broken eval_on(g, f) == map(p->f(p...), points(g))