test(mesh): add Mesh API regression

test/mesh/test_mesh_api.jl

@@ -0,0 +1,50 @@
+# SPDX-FileCopyrightText: 2015-2026 Jukka Aho
+# SPDX-License-Identifier: MIT
+
+using Test
+using JuliaFEM
+using Tensors
+
+@testset "Mesh API (connectivity, sets, surface)" begin
+    mesh = create_structured_box_mesh(Hex8, nx=2, ny=2, nz=1)
+    @test validate(mesh)
+    @test topology_type(mesh) === Hex8
+
+    cm = connectivity_matrix(mesh)
+    @test size(cm, 1) == nnodes(Hex8)
+    @test size(cm, 2) == nelements(mesh)
+    @test cm[:, 1] == collect(mesh.connectivity[1])
+
+    p = get_node(mesh, 1)
+    @test p isa Vec{3,Float64}
+
+    ec = get_elements_for_node(mesh, UInt32(1))
+    @test !isempty(ec)
+    @test get_elements_for_node(mesh, 1) == ec
+
+    els = get_elements_in_set(mesh, :all)
+    @test length(els) == nelements(mesh)
+    nds = get_nodes_in_set(mesh, :xmin)
+    @test !isempty(nds)
+
+    @test JuliaFEM.surface_topology(Hex8) === Quadrilateral{4}
+    @test JuliaFEM.surface_topology(Tet4) === Triangle{3}
+
+    surf = extract_surface(mesh, :all)
+    @test nelements(surf) == nelements(mesh)
+    @test nnodes_per_element(surf) == 4
+
+    summary = sprint() do io
+        info(io, mesh)
+    end
+    @test occursin("Mesh{", summary)
+    @test occursin("elements", sprint(show, mesh))
+end
+
+@testset "extract_surface unsupported volume topology" begin
+    nodes = [Vec((0.0, 0.0, 0.0)), Vec((1.0, 0.0, 0.0)), Vec((0.0, 1.0, 0.0)),
+             Vec((0.0, 0.0, 1.0)), Vec((1.0, 0.0, 1.0)), Vec((0.0, 1.0, 1.0))]
+    conn = [(UInt32(1), UInt32(2), UInt32(3), UInt32(4), UInt32(5), UInt32(6))]
+    mesh_w = Mesh{Wedge{6}}(nodes, conn; element_sets=Dict(:w => Set(UInt32(1))))
+    @test_throws ErrorException extract_surface(mesh_w, :w)
+end