small changes

Author: Stephan Sahm

Changelog.md

@@ -23,7 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - flatten in general is now unified to use `convert` for interoperability between similar
   container types
 - flatten of ContextManager is again reverted back to not use `FlattenMe` anymore. Instead the
-  inner result value is explicitly converted to `ContextManager`, following the general principal
+  inner result value is explicitly converted to `ContextManager`, following the general principle
   now.
 
 ### Fixed

test/promote_type.jl

@@ -29,8 +29,8 @@ using DataTypesBasic
 # Option
 # ======
 
-@test promote_type(Identity{Int}, Nothing) == Union{Identity{Int}, Nothing}
-@test promote_type(Nothing, Identity{<:Number}) == Union{Identity{<:Number}, Nothing}
+@test promote_type(Identity{Int}, Const{Nothing}) == Union{Identity{Int}, Const{Nothing}}
+@test promote_type(Const{Nothing}, Identity{<:Number}) == Union{Identity{<:Number}, Const{Nothing}}
 
 @test Dict(:a => Identity(1), :b => Const(nothing)) isa Dict{Symbol, Option{Int}}
 
@@ -60,7 +60,7 @@ using DataTypesBasic
 # OptionEither
 # ============
 
-@test promote_type(Identity{Number}, Const{Int}, Nothing) == Union{Nothing, Const{Int64}, Identity{Number}}
+@test promote_type(Identity{Number}, Const{Int}, Const{Nothing}) == Union{Const, Identity{Number}}
 
 @test promote_type(Either{Number}, Const{Nothing}) == Either
 @test promote_type(Either{Number, AbstractString}, Const{Nothing}) == Either{<:Any, AbstractString}