Array tests for convert and reverseind (#42366)

Author: kshyatt

test/abstractarray.jl

@@ -514,6 +514,9 @@ function test_primitives(::Type{T}, shape, ::Type{TestAbstractArray}) where T
     @test convert(Matrix, Y) == Y
     @test convert(Matrix, view(Y, 1:2, 1:2)) == Y
     @test_throws MethodError convert(Matrix, X)
+
+    # convert(::Type{Union{}}, A::AbstractMatrix)
+    @test_throws MethodError convert(Union{}, X)
 end
 
 mutable struct TestThrowNoGetindex{T} <: AbstractVector{T} end

test/arrayops.jl

@@ -1576,6 +1576,12 @@ end
     @test reverse!(Any[]) == Any[]
 end
 
+@testset "reverseind" begin
+    @test reverseind([1, 2, 3], 2) == 2
+    @test reverseind([1, 2, 3], 0) == 4
+    @test reverseind([1, 2, 3], 3) == 1
+end
+
 @testset "reverse dim" begin
     @test isequal(reverse([2,3,1], dims=1), [1,3,2])
     @test_throws ArgumentError reverse([2,3,1], dims=2)