--- a/test/SbpOperators/volumeops/derivatives/second_derivative_test.jl	Mon May 23 07:20:27 2022 +0200
+++ b/test/SbpOperators/volumeops/derivatives/second_derivative_test.jl	Tue Feb 10 22:41:19 2026 +0100
@@ -1,10 +1,12 @@
 using Test
 
-using Sbplib.SbpOperators
-using Sbplib.Grids
-using Sbplib.LazyTensors
+using Diffinitive.SbpOperators
+using Diffinitive.Grids
+using Diffinitive.LazyTensors
 
-import Sbplib.SbpOperators.VolumeOperator
+import Diffinitive.SbpOperators.VolumeOperator
+
+# TODO: Refactor these test to look more like the tests in first_derivative_test.jl.
 
 @testset "SecondDerivative" begin
     operator_path = sbp_operators_path()*"standard_diagonal.toml"
@@ -13,24 +15,18 @@
     closure_stencils = parse_stencil.(stencil_set["D2"]["closure_stencils"])
     Lx = 3.5
     Ly = 3.
-    g_1D = EquidistantGrid(121, 0.0, Lx)
-    g_2D = EquidistantGrid((121,123), (0.0, 0.0), (Lx, Ly))
+    g_1D = equidistant_grid(0.0, Lx, 121)
+    g_2D = equidistant_grid((0.0, 0.0), (Lx, Ly), 121, 123)
 
     @testset "Constructors" begin
         @testset "1D" begin
-            Dₓₓ = second_derivative(g_1D,inner_stencil,closure_stencils,1)
-            @test Dₓₓ == second_derivative(g_1D,inner_stencil,closure_stencils)
-            @test Dₓₓ == second_derivative(g_1D,stencil_set,1)
-            @test Dₓₓ == second_derivative(g_1D,stencil_set)
-            @test Dₓₓ isa VolumeOperator
+            Dₓₓ = second_derivative(g_1D, stencil_set)
+            @test Dₓₓ == second_derivative(g_1D, inner_stencil, closure_stencils)
+            @test Dₓₓ isa LazyTensor{Float64,1,1}
         end
         @testset "2D" begin
-            Dₓₓ = second_derivative(g_2D,inner_stencil,closure_stencils,1)
-            D2 = second_derivative(g_1D,inner_stencil,closure_stencils,1)
-            I = IdentityTensor{Float64}(size(g_2D)[2])
-            @test Dₓₓ == D2⊗I
-            @test Dₓₓ == second_derivative(g_2D,stencil_set,1)
-            @test Dₓₓ isa LazyTensor{T,2,2} where T
+            Dₓₓ = second_derivative(g_2D,stencil_set,1)
+            @test Dₓₓ isa LazyTensor{Float64,2,2}
         end
     end
 
@@ -43,10 +39,10 @@
             maxOrder = 4;
             for i = 0:maxOrder-1
                 f_i(x) = 1/factorial(i)*x^i
-                monomials = (monomials...,evalOn(g_1D,f_i))
+                monomials = (monomials...,eval_on(g_1D,f_i))
             end
-            v = evalOn(g_1D,x -> sin(x))
-            vₓₓ = evalOn(g_1D,x -> -sin(x))
+            v = eval_on(g_1D,x -> sin(x))
+            vₓₓ = eval_on(g_1D,x -> -sin(x))
 
             # 2nd order interior stencil, 1nd order boundary stencil,
             # implies that L*v should be exact for monomials up to order 2.
@@ -75,15 +71,15 @@
         end
 
         @testset "2D" begin
-            l2(v) = sqrt(prod(spacing(g_2D))*sum(v.^2));
+            l2(v) = sqrt(prod(spacing.(g_2D.grids))*sum(v.^2));
             binomials = ()
             maxOrder = 4;
             for i = 0:maxOrder-1
                 f_i(x,y) = 1/factorial(i)*y^i + x^i
-                binomials = (binomials...,evalOn(g_2D,f_i))
+                binomials = (binomials...,eval_on(g_2D,f_i))
             end
-            v = evalOn(g_2D, (x,y) -> sin(x)+cos(y))
-            v_yy = evalOn(g_2D,(x,y) -> -cos(y))
+            v = eval_on(g_2D, (x,y) -> sin(x)+cos(y))
+            v_yy = eval_on(g_2D,(x,y) -> -cos(y))
 
             # 2nd order interior stencil, 1st order boundary stencil,
             # implies that L*v should be exact for binomials up to order 2.
@@ -92,7 +88,7 @@
                 Dyy = second_derivative(g_2D,stencil_set,2)
                 @test Dyy*binomials[1] ≈ zeros(Float64,size(g_2D)...) atol = 5e-9
                 @test Dyy*binomials[2] ≈ zeros(Float64,size(g_2D)...) atol = 5e-9
-                @test Dyy*binomials[3] ≈ evalOn(g_2D,(x,y)->1.) atol = 5e-9
+                @test Dyy*binomials[3] ≈ eval_on(g_2D,(x,y)->1.) atol = 5e-9
                 @test Dyy*v ≈ v_yy rtol = 5e-2 norm = l2
             end
 
@@ -105,8 +101,8 @@
                 # due to accumulation of round-off errors/cancellation errors?
                 @test Dyy*binomials[1] ≈ zeros(Float64,size(g_2D)...) atol = 5e-9
                 @test Dyy*binomials[2] ≈ zeros(Float64,size(g_2D)...) atol = 5e-9
-                @test Dyy*binomials[3] ≈ evalOn(g_2D,(x,y)->1.) atol = 5e-9
-                @test Dyy*binomials[4] ≈ evalOn(g_2D,(x,y)->y) atol = 5e-9
+                @test Dyy*binomials[3] ≈ eval_on(g_2D,(x,y)->1.) atol = 5e-9
+                @test Dyy*binomials[4] ≈ eval_on(g_2D,(x,y)->y) atol = 5e-9
                 @test Dyy*v ≈ v_yy rtol = 5e-4 norm = l2
             end
         end