add test for JuliaLang#43599

test/reduce.jl

@@ -378,6 +378,27 @@ A = circshift(reshape(1:24,2,3,4), (0,1,1))
 @test size(extrema(A,dims=(1,2,3))) == size(maximum(A,dims=(1,2,3)))
 @test extrema(x->div(x, 2), A, dims=(2,3)) == reshape([(0,11),(1,12)],2,1,1)
 
+function test_extrema(f, a; dims)
+    vext = extrema(f, a; dims)
+    vmin, vmax = minimum(f, a; dims), maximum(f, a; dims)
+    @test all(x -> x[1] === x[2:3], zip(vext,vmin,vmax))
+end
+@testset "NaN/missing test for extrema with dims #43599" begin
+    A = randn(10,10)
+    A[rand(1:100, 4)] .= NaN
+    test_extrema(identity, A; dims = 1)
+    test_extrema(identity, A; dims = 2)
+    test_extrema(identity, A; dims = (1,2))
+    A = map(i -> isnan(i) ? missing : i, A)
+    test_extrema(identity, A; dims = 1)
+    test_extrema(identity, A; dims = 2)
+    test_extrema(identity, A; dims = (1,2))
+    A[rand(1:100, 4)] .= NaN
+    test_extrema(identity, A; dims = 1)
+    test_extrema(identity, A; dims = 2)
+    test_extrema(identity, A; dims = (1,2))
+end
+
 @testset "maximum/minimum/extrema with missing values" begin
     for x in (Vector{Union{Int,Missing}}(missing, 10),
               Vector{Union{Int,Missing}}(missing, 257))