Update tests

core/src/util.jl

@@ -70,7 +70,10 @@ function get_storages_from_levels(basin::Basin, levels::Vector)::Vector{Float64}
 
     for (i, level) in enumerate(levels)
         storage = get_storage_from_level(basin, i, level)
-        if isnan(storage)
+        bottom = first(basin.level[i])
+        node_id = basin.node_id.values[i]
+        if level < bottom
+            @error "The initial level ($level) of $node_id is below the bottom ($bottom)."
             errors = true
         end
         storages[i] = storage

core/test/utils_test.jl

@@ -114,14 +114,17 @@ end
     @test length(logger.logs) == 1
     @test logger.logs[1].level == Error
     @test logger.logs[1].message ==
-          "The level -1.0 of Basin #1 is lower than the bottom of this basin; 0.0."
+          "The initial level (-1.0) of Basin #1 is below the bottom (0.0)."
 
     # Converting from storages to levels and back should return the same storages
     storages = range(0.0, 2 * storage[end], 50)
     levels = [Ribasim.get_area_and_level(basin, 1, s)[2] for s in storages]
     storages_ = [Ribasim.get_storage_from_level(basin, 1, l) for l in levels]
-
     @test storages ≈ storages_
+
+    # At or below bottom the storage is 0
+    @test Ribasim.get_storage_from_level(basin, 1, 0.0) == 0.0
+    @test Ribasim.get_storage_from_level(basin, 1, -1.0) == 0.0
 end
 
 @testitem "Expand logic_mapping" begin