From 9ff0d68650062305d57cad6edd4131b77d0f8e6f Mon Sep 17 00:00:00 2001
From: kalmarek <kalmar@amu.edu.pl>
Date: Fri, 7 Jun 2019 18:49:51 +0200
Subject: [PATCH] AA promote_rule is not symmetric by design

---
 test/AARing_interface_conformance.jl | 19 +++++++++++++++----
 test/runtests.jl                     |  9 ++++-----
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/test/AARing_interface_conformance.jl b/test/AARing_interface_conformance.jl
index 3d6da2e..e6ce23b 100644
--- a/test/AARing_interface_conformance.jl
+++ b/test/AARing_interface_conformance.jl
@@ -3,6 +3,10 @@ using AbstractAlgebra
 
 has_base_ring(R::AbstractAlgebra.NCRing) = base_ring(R) != Union{}
 
+function AbstractAlgebra.promote_rule(::Type{S}, ::Type{T}) where {S <: Real, T <: Real}
+    return Base.promote_rule(S, T)
+end
+
 function test_data_type(f,g)
     @testset "Data type" begin
         f,g = deepcopy(f), deepcopy(g)
@@ -229,16 +233,23 @@ function test_promote_rules(f,g)
     f,g = deepcopy(f), deepcopy(g)
     @testset "promote_rules" begin
 
-        @test_broken AbstractAlgebra.promote_rule(typeof(f), Int16) == typeof(f)
-        @test_broken promote_rule(typeof(f), BigInt) == typeof(f)
+        function test_promotes(F::Type, I::Type)
+            @testset "Promote_type with $I" begin
+                @test AbstractAlgebra.promote_rule(F, I) isa Type
+                @test AbstractAlgebra.promote_rule(F, I) != Union{}
+            end
+        end
 
+        test_promotes(typeof(f), Int16)
+        test_promotes(typeof(f), Int)
+
+        test_promotes(typeof(f), typeof(g))
         @test AbstractAlgebra.promote_rule(typeof(f), typeof(g)) == typeof(f)
-        @test AbstractAlgebra.promote_rule(typeof(g), typeof(f)) == typeof(f)
 
         if has_base_ring(parent(f))
             S = base_ring(parent(f))
+            test_promotes(typeof(f), elem_type(S))
             @test AbstractAlgebra.promote_rule(typeof(f), elem_type(S)) == typeof(f)
-            @test AbstractAlgebra.promote_rule(elem_type(S), typeof(f)) == typeof(f)
         end
     end
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 9588402..7caa56a 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -4,13 +4,14 @@ using AbstractAlgebra
 using GroupRings
 using SparseArrays
 
-@testset "Group Rings tests" begin
+include("AARing_interface_conformance.jl")
 
+@testset "Group Rings tests" begin
     include("unittests.jl")
     include("usetests.jl")
 
     let
-        include("AARing_interface_conformance.jl")
+
         R = AbstractAlgebra.zz
         G = PermGroup(4)
 
@@ -19,8 +20,6 @@ using SparseArrays
         X = rand(RG, 0.2, -3:3)
         Y = rand(RG, 0.4, -1:1)
 
-        # test_ringinterface(X, Y)
-        test_promote_rules(X, Y)
+        test_ringinterface(X, Y)
     end
-
 end