diff --git a/test/nullable.jl b/test/nullable.jl
deleted file mode 100644
index 2edc67cdc3cae..0000000000000
--- a/test/nullable.jl
+++ /dev/null
@@ -1,520 +0,0 @@
-# This file is a part of Julia. License is MIT: https://julialang.org/license
-
-# "is a null with type T", curried on 2nd argument
-isnull_oftype(x::Nullable, T::Type) = eltype(x) == T && isnull(x)
-isnull_oftype(T::Type) = x -> isnull_oftype(x, T)
-
-# return true if nullables (or arrays of nullables) have the same type,
-# nullity, and value (if they are non-null)
-istypeequal(x::Nullable, y::Nullable) =
-    typeof(x) == typeof(y) && isnull(filter(!, x .== y))
-istypeequal(x::AbstractArray, y::AbstractArray) =
-    length(x) == length(y) && all(xy -> istypeequal(xy...), zip(x, y))
-
-types = [
-    Bool,
-    Float16,
-    Float32,
-    Float64,
-    Int128,
-    Int16,
-    Int32,
-    Int64,
-    Int8,
-    UInt16,
-    UInt32,
-    UInt64,
-    UInt8,
-]
-
-# Nullable{T}() = new(true)
-for T in types
-    x = Nullable{T}()
-    @test x.hasvalue === false
-    @test isa(x.value, T)
-    @test eltype(Nullable{T}) === T
-    @test eltype(x) === T
-end
-
-# Nullable{T}(value::T) = new(false, value)
-for T in types
-    x = Nullable{T}(zero(T))
-    @test x.hasvalue === true
-    @test isa(x.value, T)
-    @test x.value === zero(T)
-    @test eltype(x) === T
-
-    x = Nullable{T}(one(T))
-    @test x.hasvalue === true
-    @test isa(x.value, T)
-    @test x.value === one(T)
-    @test eltype(x) === T
-end
-
-# Nullable{T}(value::T, hasvalue::Bool) = new(hasvalue, value)
-for T in types
-    x = Nullable{T}(zero(T), true)
-    @test x.hasvalue === true
-    @test isa(x.value, T)
-    @test x.value === zero(T)
-    @test eltype(x) === T
-
-    x = Nullable{T}(zero(T), false)
-    @test x.hasvalue === false
-    @test isa(x.value, T)
-    @test eltype(Nullable{T}) === T
-    @test eltype(x) === T
-end
-
-
-# struct NullException <: Exception
-@test isa(NullException(), NullException)
-@test_throws NullException throw(NullException())
-
-# Nullable{T}(value::T) = Nullable{T}(value)
-for T in types
-    v = zero(T)
-    x = Nullable(v)
-    @test x.hasvalue === true
-    @test isa(x.value, T)
-    @test x.value === v
-
-    v = one(T)
-    x = Nullable(v)
-    @test x.hasvalue === true
-    @test isa(x.value, T)
-    @test x.value === v
-end
-
-# show{T}(io::IO, x::Nullable{T})
-io1 = IOBuffer()
-io2 = IOBuffer()
-for (i, T) in enumerate(types)
-    x1 = Nullable{T}()
-    x2 = Nullable(zero(T))
-    x3 = Nullable(one(T))
-    show(io1, x1)
-    @test String(take!(io1)) == @sprintf("Nullable{%s}()", T)
-    show(io1, x2)
-    showcompact(io2, get(x2))
-    @test String(take!(io1)) == @sprintf("Nullable{%s}(%s)", T, String(take!(io2)))
-    show(io1, x3)
-    showcompact(io2, get(x3))
-    @test String(take!(io1)) == @sprintf("Nullable{%s}(%s)", T, String(take!(io2)))
-end
-
-module NullableTestEnum
-import Test
-# For curmod_*
-include("testenv.jl")
-io = IOBuffer()
-@enum TestEnum a b
-show(io, Nullable(a))
-Test.@test String(take!(io)) == "Nullable{$(curmod_prefix)TestEnum}(a)"
-end
-
-# showcompact(io::IO, x::Nullable)
-io1 = IOBuffer()
-io2 = IOBuffer()
-for (i, T) in enumerate(types)
-    x1 = Nullable{T}()
-    x2 = Nullable(zero(T))
-    x3 = Nullable(one(T))
-    showcompact(io1, x1)
-    @test String(take!(io1)) == "#NULL"
-    showcompact(io1, x2)
-    showcompact(io2, get(x2))
-    @test String(take!(io1)) == String(take!(io2))
-    showcompact(io1, x3)
-    showcompact(io2, get(x3))
-    @test String(take!(io1)) == String(take!(io2))
-
-    a1 = [x2]
-    showcompact(io1, a1)
-    showcompact(io2, x2)
-    @test String(take!(io1)) ==
-        @sprintf("Nullable{%s}[%s]", string(T), String(take!(io2)))
-end
-
-# get(x::Nullable)
-for T in types
-    x1 = Nullable{T}()
-    x2 = Nullable(zero(T))
-    x3 = Nullable(one(T))
-
-    @test_throws NullException get(x1)
-    @test get(x2) === zero(T)
-    @test get(x3) === one(T)
-end
-
-@test_throws NullException get(Nullable())
-
-# get{S, T}(x::Nullable{S}, y::T)
-for T in types
-    x0 = Nullable()
-    x1 = Nullable{T}()
-    x2 = Nullable(zero(T))
-    x3 = Nullable(one(T))
-
-    @test get(x0, zero(T)) === zero(T)
-    @test get(x0, one(T)) === one(T)
-    @test get(x1, zero(T)) === zero(T)
-    @test get(x1, one(T)) === one(T)
-    @test get(x2, one(T)) === zero(T)
-    @test get(x3, zero(T)) === one(T)
-end
-
-for T in types
-    # unsafe_get(x::Nullable)
-    x1 = Nullable{T}()
-    x2 = Nullable(zero(T))
-    x3 = Nullable(one(T))
-    a = rand(T)
-    x4 = Nullable(a)
-
-    @test isa(unsafe_get(x1), T)
-    @test unsafe_get(x2) === zero(T)
-    @test unsafe_get(x3) === one(T)
-    @test unsafe_get(x4) === a
-
-    # unsafe_get(x)
-    x2 = zero(T)
-    x3 = one(T)
-    x4 = rand(T)
-
-    @test unsafe_get(x2) === zero(T)
-    @test unsafe_get(x3) === one(T)
-    @test unsafe_get(x4) === x4
-end
-
-@test_throws UndefRefError unsafe_get(Nullable())
-@test_throws UndefRefError unsafe_get(Nullable{String}())
-@test_throws UndefRefError unsafe_get(Nullable{Array}())
-
-for T in types
-    # isnull(x::Nullable)
-    x1 = Nullable{T}()
-    x2 = Nullable(zero(T))
-    x3 = Nullable(one(T))
-
-    @test isnull(x1) === true
-    @test isnull(x2) === false
-    @test isnull(x3) === false
-
-    # isnull(x)
-    x1 = zero(T)
-    x2 = one(T)
-    x3 = rand(T)
-
-    @test isnull(x1) === false
-    @test isnull(x2) === false
-    @test isnull(x3) === false
-end
-
-@test isnull(Nullable())
-
-# function =={S, T}(x::Nullable{S}, y::Nullable{T})
-for T in types
-    x0 = Nullable()
-    x1 = Nullable{T}()
-    x2 = Nullable{T}()
-    x3 = Nullable(zero(T))
-    x4 = Nullable(one(T))
-
-    @test_throws NullException (x0 == x1)
-    @test_throws NullException (x0 == x2)
-    @test_throws NullException (x0 == x3)
-    @test_throws NullException (x0 == x4)
-
-    @test_throws NullException (x1 == x1)
-    @test_throws NullException (x1 == x2)
-    @test_throws NullException (x1 == x3)
-    @test_throws NullException (x1 == x4)
-
-    @test_throws NullException (x2 == x1)
-    @test_throws NullException (x2 == x2)
-    @test_throws NullException (x2 == x3)
-    @test_throws NullException (x2 == x4)
-
-    @test_throws NullException (x3 == x1)
-    @test_throws NullException (x3 == x2)
-    @test_throws NullException (x3 == x3)
-    @test_throws NullException (x3 == x4)
-
-    @test_throws NullException (x4 == x1)
-    @test_throws NullException (x4 == x2)
-    @test_throws NullException (x4 == x3)
-    @test_throws NullException (x4 == x4)
-end
-
-# function hash(x::Nullable, h::UInt)
-for T in types
-    x0 = Nullable()
-    x1 = Nullable{T}()
-    x2 = Nullable{T}()
-    x3 = Nullable(zero(T))
-    x4 = Nullable(one(T))
-
-    @test isa(hash(x0), UInt)
-    @test isa(hash(x1), UInt)
-    @test isa(hash(x2), UInt)
-    @test isa(hash(x3), UInt)
-    @test isa(hash(x4), UInt)
-
-    @test hash(x0) == hash(x2)
-    @test hash(x0) != hash(x3)
-    @test hash(x0) != hash(x4)
-    @test hash(x1) == hash(x2)
-    @test hash(x1) != hash(x3)
-    @test hash(x1) != hash(x4)
-    @test hash(x2) != hash(x3)
-    @test hash(x2) != hash(x4)
-    @test hash(x3) != hash(x4)
-end
-
-mutable struct TestNType{T}
-    v::Nullable{T}
-end
-
-for T in types
-    x1 = TestNType{T}(Nullable{T}())
-    @test isnull(x1.v)
-    x1.v = one(T)
-    @test !isnull(x1.v)
-    @test get(x1.v, one(T)) === one(T)
-end
-
-# Operators
-TestTypes = [[T.parameters[1] for T in Base.uniontypes(Base.NullSafeTypes)];
-             [BigInt, BigFloat,
-              Complex{Int}, Complex{Float64}, Complex{BigFloat},
-              Rational{Int}, Rational{BigInt}]]
-for S in TestTypes, T in TestTypes
-    u0 = zero(S)
-    u1 = one(S)
-    if S <: AbstractFloat
-        u2 = S(NaN)
-    elseif S <: Complex && S.parameters[1] <: AbstractFloat
-        u2 = S(NaN, NaN)
-    else
-        u2 = u1
-    end
-
-    v0 = zero(T)
-    v1 = one(T)
-    if T <: AbstractFloat
-        v2 = T(NaN)
-    elseif T <: Complex && T.parameters[1] <: AbstractFloat
-        v2 = T(NaN, NaN)
-    else
-        v2 = v1
-    end
-
-    for u in (u0, u1, u2), v in (v0, v1, v2)
-        # function isequal(x::Nullable, y::Nullable)
-        @test isequal(Nullable(u), Nullable(v)) === isequal(u, v)
-        @test isequal(Nullable(u), Nullable(u)) === true
-        @test isequal(Nullable(v), Nullable(v)) === true
-
-        @test isequal(Nullable(u), Nullable(v, false)) === false
-        @test isequal(Nullable(u, false), Nullable(v)) === false
-        @test isequal(Nullable(u, false), Nullable(v, false)) === true
-
-        @test isequal(Nullable(u), Nullable{T}()) === false
-        @test isequal(Nullable{S}(), Nullable(v)) === false
-        @test isequal(Nullable{S}(), Nullable{T}()) === true
-
-        @test isequal(Nullable(u), Nullable()) === false
-        @test isequal(Nullable(), Nullable(v)) === false
-        @test isequal(Nullable{S}(), Nullable()) === true
-        @test isequal(Nullable(), Nullable{T}()) === true
-        @test isequal(Nullable(), Nullable()) === true
-
-        # function isless(x::Nullable, y::Nullable)
-        if S <: Real && T <: Real
-            @test isless(Nullable(u), Nullable(v)) === isless(u, v)
-            @test isless(Nullable(u), Nullable(u)) === false
-            @test isless(Nullable(v), Nullable(v)) === false
-
-            @test isless(Nullable(u), Nullable(v, false)) === true
-            @test isless(Nullable(u, false), Nullable(v)) === false
-            @test isless(Nullable(u, false), Nullable(v, false)) === false
-
-            @test isless(Nullable(u), Nullable{T}()) === true
-            @test isless(Nullable{S}(), Nullable(v)) === false
-            @test isless(Nullable{S}(), Nullable{T}()) === false
-
-            @test isless(Nullable(u), Nullable()) === true
-            @test isless(Nullable(), Nullable(v)) === false
-            @test isless(Nullable{S}(), Nullable()) === false
-            @test isless(Nullable(), Nullable{T}()) === false
-            @test isless(Nullable(), Nullable()) === false
-        end
-    end
-end
-
-# issue #9462
-for T in types
-    @test isa(convert(Nullable{Number}, Nullable(one(T))), Nullable{Number})
-    @test isa(convert(Nullable{Number}, one(T)), Nullable{Number})
-    @test isa(convert(Nullable{T}, one(T)), Nullable{T})
-    @test isa(convert(Nullable{Any}, Nullable(one(T))), Nullable{Any})
-    @test isa(convert(Nullable{Any}, one(T)), Nullable{Any})
-
-    # one(T) is convertible to every type in types
-    # let's test that with Nullables
-    for S in types
-        @test isa(convert(Nullable{T}, one(S)), Nullable{T})
-    end
-end
-
-@test isnull(convert(Nullable, nothing))
-@test isnull(convert(Nullable{Int}, nothing))
-@test isa(convert(Nullable{Int}, nothing), Nullable{Int})
-
-@test convert(Nullable, 1) === Nullable(1)
-@test convert(Nullable, Nullable(1)) === Nullable(1)
-@test isequal(convert(Nullable, "a"), Nullable("a"))
-@test isequal(convert(Nullable, Nullable("a")), Nullable("a"))
-
-using Dates
-@test promote_type(Nullable{Int}, Int) === Nullable{Int}
-@test promote_type(Nullable{Union{}}, Int) === Nullable{Int}
-@test promote_type(Nullable{Float64}, Nullable{Int}) === Nullable{Float64}
-@test promote_type(Nullable{Union{}}, Nullable{Int}) === Nullable{Int}
-@test promote_type(Nullable{Date}, Nullable{DateTime}) === Nullable{DateTime}
-
-@test Base.promote_op(+, Nullable{Int}, Nullable{Int}) == Nullable{Int}
-@test Base.promote_op(-, Nullable{Int}, Nullable{Int}) == Nullable{Int}
-@test Base.promote_op(+, Nullable{Float64}, Nullable{Int}) == Nullable{Float64}
-@test Base.promote_op(-, Nullable{Float64}, Nullable{Int}) == Nullable{Float64}
-@test Base.promote_op(-, Nullable{DateTime}, Nullable{DateTime}) == Nullable{Dates.Millisecond}
-
-# tests for istypeequal (which uses filter, broadcast)
-@test istypeequal(Nullable(0), Nullable(0))
-@test !istypeequal(Nullable(0), Nullable(0.0))
-@test !istypeequal(Nullable(0), Nullable(1))
-@test !istypeequal(Nullable(0), Nullable(1.0))
-@test istypeequal([Nullable(0), Nullable(1)], [Nullable(0), Nullable(1)])
-@test istypeequal([Nullable(0), Nullable(1)], Any[Nullable(0), Nullable(1)])
-@test !istypeequal([Nullable(0), Nullable(1)], Any[Nullable(0.0), Nullable(1)])
-@test !istypeequal([Nullable(0), Nullable(1)], [Nullable(0), Nullable(2)])
-@test !istypeequal([Nullable(0), Nullable(1)],
-                   [Nullable(0), Nullable(1), Nullable(2)])
-
-# filter
-for p in (_ -> true, _ -> false)
-    @test @inferred(filter(p, Nullable()))      |> isnull_oftype(Union{})
-    @test @inferred(filter(p, Nullable{Int}())) |> isnull_oftype(Int)
-end
-@test @inferred(filter(_ -> true, Nullable(85)))  === Nullable(85)
-@test @inferred(filter(_ -> false, Nullable(85))) |> isnull_oftype(Int)
-@test @inferred(filter(x -> x > 0, Nullable(85))) === Nullable(85)
-@test @inferred(filter(x -> x < 0, Nullable(85))) |> isnull_oftype(Int)
-@test get(@inferred(filter(x -> length(x) > 2, Nullable("test")))) == "test"
-@test @inferred(filter(x -> length(x) > 5, Nullable("test"))) |>
-    isnull_oftype(String)
-
-# map
-sqr(x) = x^2
-@test @inferred(map(sqr, Nullable()))        |> isnull_oftype(Union{})
-@test @inferred(map(sqr, Nullable{Int}()))   |> isnull_oftype(Int)
-@test @inferred(map(sqr, Nullable(2)))       === Nullable(4)
-@test @inferred(map(+, Nullable(0.0)))       === Nullable(0.0)
-@test @inferred(map(+, Nullable(3.0, false)))=== Nullable(3.0, false)
-@test @inferred(map(-, Nullable(1.0)))       === Nullable(-1.0)
-@test @inferred(map(-, Nullable{Float64}())) |> isnull_oftype(Float64)
-@test @inferred(map(sin, Nullable(1)))       === Nullable(sin(1))
-@test @inferred(map(sin, Nullable{Int}()))   |> isnull_oftype(Float64)
-
-# should not throw if function wouldn't be called
-@test map(x -> x ? 0 : 0.0, Nullable())       |> isnull_oftype(Union{})
-@test map(x -> x ? 0 : 0.0, Nullable(true))   === Nullable(0)
-@test map(x -> x ? 0 : 0.0, Nullable(false))  === Nullable(0.0)
-@test map(x -> x ? 0 : 0.0, Nullable{Bool}()) |> isnull_oftype(Union{})
-
-# broadcast and elementwise
-@test sin.(Nullable(0.0))            === Nullable(0.0)
-@test sin.(Nullable{Float64}())      |> isnull_oftype(Float64)
-@test @inferred(broadcast(sin, Nullable(0.0)))       === Nullable(0.0)
-@test @inferred(broadcast(sin, Nullable{Float64}())) |> isnull_oftype(Float64)
-
-@test Nullable(8) .+ Nullable(10)     === Nullable(18)
-@test Nullable(8) .- Nullable(10)     === Nullable(-2)
-@test Nullable(8) .+ Nullable{Int}()  |> isnull_oftype(Int)
-@test Nullable{Int}() .- Nullable(10) |> isnull_oftype(Int)
-
-@test @inferred(broadcast(log, 10, Nullable(1.0))) ===
-      Nullable(0.0)
-@test @inferred(broadcast(log, 10, Nullable{Float64}())) |>
-      isnull_oftype(Float64)
-@test @inferred(broadcast(log, Nullable(10), Nullable(1.0))) ===
-      Nullable(0.0)
-@test @inferred(broadcast(log, Nullable(10), Nullable{Float64}())) |>
-      isnull_oftype(Float64)
-
-@test Nullable(2) .^ Nullable(4)      === Nullable(16)
-@test Nullable(2) .^ Nullable{Int}()  |> isnull_oftype(Int)
-
-# multi-arg broadcast
-@test (Nullable(1) .+ Nullable(1) .+ Nullable(1) .+ Nullable(1) .+ Nullable(1) .+
-       Nullable(1) === Nullable(6))
-@test (Nullable(1) .+ Nullable(1) .+ Nullable(1) .+ Nullable{Int}() .+
-       Nullable(1) .+ Nullable(1) |> isnull_oftype(Int))
-
-# these are not inferrable because there are too many arguments
-us = map(Nullable, 1:20)
-@test broadcast(max, us...) === Nullable(20)
-@test isnull(broadcast(max, us..., Nullable{Int}()))
-
-# test all elementwise operations
-# note that elementwise operations are the same as broadcast
-for op in (+, -, *, /, \, //, ==, <, !=, <=, ÷, %, <<, >>, ^)
-    # op(1, 1) chosen because it works for all operations
-    res = op(1, 1)
-    @test @inferred(broadcast(op, Nullable(1), Nullable(1)))         ===
-          Nullable(res)
-    @test @inferred(broadcast(op, Nullable{Int}(), Nullable(1)))     |>
-          isnull_oftype(typeof(res))
-    @test @inferred(broadcast(op, Nullable(1), Nullable{Int}()))     |>
-          isnull_oftype(typeof(res))
-    @test @inferred(broadcast(op, Nullable{Int}(), Nullable{Int}())) |>
-          isnull_oftype(typeof(res))
-    @test @inferred(broadcast(op, Nullable(1), 1))                   ===
-          Nullable(res)
-    @test @inferred(broadcast(op, 1, Nullable(1)))                   ===
-          Nullable(res)
-end
-
-# test reasonable results for Union{}
-# the exact types of these is finnicky and depends on implementation details
-# but is guaranteed to be at worst concrete and possibly Union{} on a good day
-@test isnull(@inferred(Nullable() .+ Nullable()))
-@test isnull(@inferred(Nullable() .+ 1))
-@test isnull(@inferred(Nullable() .+ Nullable(1)))
-
-# test that things don't pessimize because of non-homogenous types
-@test Nullable(10.5) ===
-    @inferred(broadcast(+, 1, 2, Nullable(3), Nullable(4.0), Nullable(1//2)))
-
-# test fast path taken
-for op in (+, *, -)
-    for b1 in (false, true)
-        for b2 in (false, true)
-            @test Nullable{Int}(op(1, 2), b1 & b2) ===
-                @inferred(broadcast(op, Nullable{Int}(1, b1),
-                                        Nullable{Int}(2, b2)))
-        end
-    end
-end
-
-# issue #11675
-@test repr(Nullable()) == "Nullable{Union{}}()"
-
-# issue #19270
-let f19270(x::S, y::T) where {S,T} = Base.promote_op(^, S, T)
-    @test f19270(Nullable(0.0f0), Nullable(BigInt(0))) == Nullable{Float32}
-end
-
-# issue #21397
-@test Nullable(Tuple) === Nullable{DataType}(Tuple)