Revert "Revert "Add rand_tangent for types (#172)""

This reverts commit 65ab55c.

Author: Miha Zgubic

Diff for: Project.toml

@@ -1,6 +1,6 @@
 name = "FiniteDifferences"
 uuid = "26cc04aa-876d-5657-8c51-4c34ba976000"
-version = "0.12.11"
+version = "0.12.12"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

Diff for: src/rand_tangent.jl

@@ -57,3 +57,6 @@ function rand_tangent(rng::AbstractRNG, x::T) where {T}
         Tangent{T}(; NamedTuple{field_names}(tangents)...)
     end
 end
+
+rand_tangent(rng::AbstractRNG, ::Type) = NoTangent()
+rand_tangent(rng::AbstractRNG, ::Module) = NoTangent()

Diff for: test/rand_tangent.jl

@@ -11,6 +11,15 @@ using FiniteDifferences: rand_tangent
         (:a, NoTangent),
         (true, NoTangent),
         (4, NoTangent),
+        (FiniteDifferences, NoTangent),  # Module object
+        # Types (not instances of type)
+        (Foo, NoTangent),  
+        (Union{Int, Foo}, NoTangent),
+        (Union{Int, Foo}, NoTangent),
+        (Vector, NoTangent),
+        (Vector{Float64}, NoTangent),
+        (Integer, NoTangent),
+        (Type{<:Real}, NoTangent),
 
         # Numbers.
         (5.0, Float64),