Revert "autotangent mapreduce tests"

This reverts commit 440591e.

Author: Miha Zgubic

test/rulesets/Base/mapreduce.jl

@@ -2,23 +2,39 @@
     @testset "sum" begin
         sizes = (3, 4, 7)
         @testset "dims = $dims" for dims in (:, 1)
+            fkwargs = (dims=dims,)
             @testset "Array{$N, $T}" for N in eachindex(sizes), T in (Float64, ComplexF64)
                 s = sizes[1:N]
                 x = randn(T, s...)
-                test_frule(sum, x; fkwargs=(;dims=dims))
-                test_rrule(sum, x; fkwargs=(;dims=dims))
+                ẋ = randn(T, s...)
+                x̄ = randn(T, s...)
+                y = sum(x; dims=dims)
+                Δy = randn(eltype(y), size(y)...)
+                frule_test(sum, (x, ẋ); fkwargs=fkwargs)
+                rrule_test(sum, Δy, (x, x̄); fkwargs=fkwargs)
             end
         end
     end  # sum
 
     @testset "sum abs2" begin
         sizes = (3, 4, 7)
         @testset "dims = $dims" for dims in (:, 1)
+            fkwargs = (dims=dims,)
             @testset "Array{$N, $T}" for N in eachindex(sizes), T in (Float64, ComplexF64)
                 s = sizes[1:N]
-                x = randn(T, s...)
-                test_frule(sum, abs2, x; fkwargs=(;dims=dims))
-                test_rrule(sum, abs2 ⊢ nothing, x; fkwargs=(;dims=dims))
+                x, ẋ, x̄ = randn(T, s...), randn(T, s...), randn(T, s...)
+                y = sum(abs2, x; dims=dims)
+                Δy = randn(eltype(y), size(y)...)
+                @testset "frule" begin
+                    # can't use frule_test here because it doesn't yet ignore nothing tangents
+                    y_ad, ẏ_ad = frule((Zero(), Zero(), ẋ), sum, abs2, x; dims=dims)
+                    @test y_ad == y
+                    ẏ_fd = jvp(_fdm, z -> sum(abs2, z; dims=dims), (x, ẋ))
+                    @test ẏ_ad ≈ ẏ_fd
+                end
+                @testset "rrule" begin
+                    rrule_test(sum, Δy, (abs2, nothing), (x, x̄); fkwargs=fkwargs)
+                end
             end
         end
     end  # sum abs2