Fix wrong default in ReactantExt for ImmersedBoundaryGrid (#4177)

* Fix wrong default in ReactantExt

* Add another test with SplitExplicit

* Comment out problematic test

Author: glwagner

ext/OceananigansReactantExt/Grids.jl

@@ -115,7 +115,7 @@ function reactant_immersed_boundary_grid(grid, ib; active_cells_map, active_z_co
 end
 
 function ImmersedBoundaryGrid(grid::ReactantUnderlyingGrid, ib::AbstractImmersedBoundary;
-                              active_cells_map::Bool=true,
+                              active_cells_map::Bool=false,
                               active_z_columns::Bool=active_cells_map)
 
     return reactant_immersed_boundary_grid(grid, ib; active_cells_map, active_z_columns)

test/test_reactant.jl

@@ -20,12 +20,23 @@ using Random
 
 OceananigansReactantExt = Base.get_extension(Oceananigans, :OceananigansReactantExt)
 
-function test_reactant_model_correctness(GridType, ModelType, grid_kw, model_kw)
+bottom_height(x, y) = - 0.5
+
+function test_reactant_model_correctness(GridType, ModelType, grid_kw, model_kw; immersed_boundary_grid=true)
     r_arch = ReactantState()
     r_grid = GridType(r_arch; grid_kw...)
-    r_model = ModelType(; grid=r_grid, model_kw...)
-
     grid = GridType(CPU(); grid_kw...)
+
+    if immersed_boundary_grid
+        grid = ImmersedBoundaryGrid(grid, GridFittedBottom(bottom_height))
+        r_grid = ImmersedBoundaryGrid(r_grid, GridFittedBottom(bottom_height))
+        @test isnothing(r_grid.interior_active_cells)
+        @test isnothing(r_grid.active_z_columns)
+        @test isnothing(grid.interior_active_cells)
+        @test isnothing(grid.active_z_columns)
+    end
+
+    r_model = ModelType(; grid=r_grid, model_kw...)
     model = ModelType(; grid=grid, model_kw...)
 
     ui = randn(size(model.velocities.u)...)
@@ -83,7 +94,7 @@ function test_reactant_model_correctness(GridType, ModelType, grid_kw, model_kw)
     @test parent(v) ≈ parent(rv)
     @test parent(w) ≈ parent(rw)
 
-    return nothing
+    return r_simulation
 end
 
 function add_one!(f)
@@ -188,15 +199,18 @@ end
 end
 
 @testset "Reactant Super Simple Simulation Tests" begin
+    @info "Performing Reactanigans super simple simulation tests..."
     nonhydrostatic_model_kw = (; advection=WENO())
     hydrostatic_model_kw = (; momentum_advection=WENO())
     Nx, Ny, Nz = (10, 10, 10) # number of cells
     halo = (7, 7, 7)
     longitude = (0, 4)
+    stretched_longitude = [0, 0.1, 0.2, 0.3, 0.4, 0.6, 1.3, 2.5, 2.6, 3.5, 4.0]
     latitude = (0, 4)
     z = (-1, 0)
     lat_lon_kw = (; size=(Nx, Ny, Nz), halo, longitude, latitude, z)
     rectilinear_kw = (; size=(Nx, Ny, Nz), halo, x=(0, 1), y=(0, 1), z=(0, 1))
+    stretched_lat_lon_kw = (; size=(Nx, Ny, Nz), halo, longitude=stretched_longitude, latitude, z)
 
     # FFTs are not supported by Reactant so we don't run this test:
     # @info "Testing RectilinearGrid + NonhydrostaticModel Reactant correctness"
@@ -205,10 +219,24 @@ end
     @info "Testing RectilinearGrid + HydrostaticFreeSurfaceModel Reactant correctness"
     hydrostatic_model_kw = (; free_surface=ExplicitFreeSurface(gravitational_acceleration=1))
     test_reactant_model_correctness(RectilinearGrid, HydrostaticFreeSurfaceModel, rectilinear_kw, hydrostatic_model_kw)
+    test_reactant_model_correctness(RectilinearGrid, HydrostaticFreeSurfaceModel, rectilinear_kw, hydrostatic_model_kw, immersed_boundary_grid=true)
 
     @info "Testing LatitudeLongitudeGrid + HydrostaticFreeSurfaceModel Reactant correctness"
     hydrostatic_model_kw = (; momentum_advection=WENO())
     test_reactant_model_correctness(LatitudeLongitudeGrid, HydrostaticFreeSurfaceModel, lat_lon_kw, hydrostatic_model_kw)
+    test_reactant_model_correctness(LatitudeLongitudeGrid, HydrostaticFreeSurfaceModel, lat_lon_kw, hydrostatic_model_kw, immersed_boundary_grid=true)
+
+    #=
+    # This test takes too long
+    @info "Testing LatitudeLongitudeGrid + SplitExplicitFreeSurface + HydrostaticFreeSurfaceModel Reactant correctness"
+    hydrostatic_model_kw = (; momentum_advection=WENOVectorInvariant(), free_surface=SplitExplicitFreeSurface(substeps=4))
+    test_reactant_model_correctness(LatitudeLongitudeGrid, HydrostaticFreeSurfaceModel, lat_lon_kw, hydrostatic_model_kw)
+    simulation = test_reactant_model_correctness(LatitudeLongitudeGrid, HydrostaticFreeSurfaceModel, lat_lon_kw, hydrostatic_model_kw, immersed_boundary_grid=true)
+    η = simulation.model.free_surface.η
+    η_grid = η.grid
+    @test isnothing(η_grid.interior_active_cells)
+    @test isnothing(η_grid.active_z_columns)
+    =#
 
     #=
     equation_of_state = TEOS10EquationOfState()