Fix conversion of Ok

Project.toml

@@ -1,7 +1,7 @@
 name = "ErrorTypes"
 uuid = "7f495686-c6d2-4c77-9e8e-e4c865675f9d"
 authors = ["Jakob Nybo Nissen <jakobnybonissen@gmail.com>"]
-version = "0.1.0"
+version = "0.2.0"
 
 [deps]
 SumTypes = "8e1ec7a9-0e02-4297-b0fe-6433085c89f2"

src/ErrorTypes.jl

@@ -72,7 +72,11 @@ end
 # Convert an error to another error if the former is a subtype of the other
 function Base.convert(::Type{Result{O1, E1}}, x::Result{O2, E2}
 ) where {O1, E1, O2 <: O1, E2 <: E1}
-    Err{O1, E1}(x.data._1)
+    if x.data isa Err
+        Err{O1, E1}(x.data._1)
+    else
+        Ok{O1, E1}(x.data._1)
+    end
 end
 
 # Convert Result value that contains an Err, even if the Ok parameter

test/runtests.jl

@@ -86,6 +86,7 @@ end
 
     # convert a result directly to another if all the subtypes match
     @test convert(Result{Integer, AbstractString}, Err{Int, String}("boo")) isa Result{Integer, AbstractString}
+    @test convert(Result{Signed, String}, Ok{Int32, String}(Int32(9))) isa Result{Signed, String}
     @test_throws MethodError convert(Result{Dict, Array}, Ok{Int, Bool}(1))
 
     # convert Result values with differing params. It works if the param of