From 36f8400a738953856d083cbfc73e977cb0522e46 Mon Sep 17 00:00:00 2001
From: Rafael Schouten <rafaelschouten@gmail.com>
Date: Sun, 1 Oct 2023 08:22:34 +0200
Subject: [PATCH 1/2] add singleton traits (#15)

* add singleton traits

* test traits

* test that passing an object rather than a type works

* Update src/implements.jl

Co-authored-by: Guillaume Dalle <22795598+gdalle@users.noreply.github.com>

---------

Co-authored-by: Guillaume Dalle <22795598+gdalle@users.noreply.github.com>
---
 src/implements.jl | 23 ++++++++++++++++++++++-
 test/runtests.jl  |  6 ++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/implements.jl b/src/implements.jl
index 3f5406b..9129ade 100644
--- a/src/implements.jl
+++ b/src/implements.jl
@@ -15,7 +15,8 @@ Without specifying `Options`, the return value specifies that at least
 all the mandatory components of the interace are implemented.
 """
 function implements end
-implements(::Type{<:Interface}, obj) = false
+implements(T::Type{<:Interface}, obj) = implements(T, typeof(obj))
+implements(::Type{<:Interface}, obj::Type) = false
 
 """
     @implements(interface, objtype)
@@ -67,3 +68,23 @@ end
 
 _all_in(items::Tuple, collection) = all(map(in(collection), items))
 _all_in(item::Symbol, collection) = in(item, collection)
+
+struct Implemented{T<:Interface} end
+struct NotImplemented{T<:Interface} end
+
+"""
+    implemented_trait(T::Type{<:Interface}, obj)
+    implemented_trait(T::Type{<:Interface{Option}}, obj)
+
+Provides a single type for using interface implementation
+as a trait.
+
+Returns `Implemented{T}()` or `NotImplemented{T}()`.
+"""
+function implemented_trait(::Type{T}, obj) where T<:Interface
+    if implements(T, obj)
+        Implemented{T}()
+    else
+        NotImplemented{T}()
+    end
+end
diff --git a/test/runtests.jl b/test/runtests.jl
index 8c3c9da..27970e3 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -41,7 +41,13 @@ Animals.talk(::Duck) = :quack
 @testset "duck" begin
     ducks = [Duck(1), Duck(2)]
     @test Interfaces.implements(Animals.AnimalInterface, Duck) == true
+    @test Interfaces.implements(Animals.AnimalInterface, first(ducks)) == true
     @test Interfaces.implements(Animals.AnimalInterface{:dig}, Duck) == false
+    @test Interfaces.implements(Animals.AnimalInterface{:dig}, first(ducks)) == false
+    @test @inferred Interfaces.implemented_trait(Animals.AnimalInterface{:walk}, Duck) == Interfaces.Implemented{Animals.AnimalInterface{:walk}}()
+    @test @inferred Interfaces.implemented_trait(Animals.AnimalInterface{:walk}, first(ducks)) == Interfaces.Implemented{Animals.AnimalInterface{:walk}}()
+    @test @inferred Interfaces.implemented_trait(Animals.AnimalInterface{:dig}, Duck) == Interfaces.NotImplemented{Animals.AnimalInterface{:dig}}()
+    @test @inferred Interfaces.implemented_trait(Animals.AnimalInterface{:dig}, first(ducks)) == Interfaces.NotImplemented{Animals.AnimalInterface{:dig}}()
     @test Interfaces.test(Animals.AnimalInterface, Duck, ducks) == true
     @test Interfaces.test(Animals.AnimalInterface{(:walk,:talk)}, Duck, ducks) == true
     # TODO wrap errors somehow, or just let Invariants.jl handle that.

From e7936228c2e271fb256e4adea279a67cf632d6bb Mon Sep 17 00:00:00 2001
From: Rafael Schouten <rafaelschouten@gmail.com>
Date: Sun, 1 Oct 2023 14:52:23 +0200
Subject: [PATCH 2/2] add aqua tests (#19)

* add aqua tests

* add aqua dep
---
 Project.toml     |  4 +++-
 src/test.jl      | 15 +++++++++------
 test/runtests.jl |  3 +++
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/Project.toml b/Project.toml
index 53e524a..b257b01 100644
--- a/Project.toml
+++ b/Project.toml
@@ -7,7 +7,9 @@ version = "0.1.0"
 julia = "1.6"
 
 [extras]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test"]
+test = ["Aqua", "Documenter", "Test"]
diff --git a/src/test.jl b/src/test.jl
index 51fcbcd..0a8a5da 100644
--- a/src/test.jl
+++ b/src/test.jl
@@ -18,15 +18,21 @@ If no interface type is passed, Interfaces.jl will find all the
 interfaces available and test them.
 """
 function test(T::Type{<:Interface{Keys}}, O::Type, test_objects; kw...) where Keys
+    # Allow passing the keys in the abstract type
+    # But get them out and put them in the `keys` keyword
     T1 = _get_type(T).name.wrapper
     objs = TestObjectWrapper(test_objects)
-    return test(T1, O, objs; keys=Keys, kw...)
+    # And run the tests on the parameterless type
+    return _test(T1, O, objs; keys=Keys, kw...)
 end
 function test(T::Type{<:Interface}, O::Type, test_objects; kw...)
     objs = TestObjectWrapper(test_objects)
-    return test(T, O, objs; kw...)
+    return _test(T, O, objs; kw...)
 end
-function test(T::Type{<:Interface}, O::Type, objs::TestObjectWrapper;
+# Convenience method for users to test a single object
+test(T::Type{<:Interface}, obj; kw...) = test(T, typeof(obj), (obj,); kw...)
+
+function _test(T::Type{<:Interface}, O::Type, objs::TestObjectWrapper;
     show=true, keys=nothing
 )
     if show
@@ -52,9 +58,6 @@ function test(T::Type{<:Interface}, O::Type, objs::TestObjectWrapper;
         return all(_bool(results))
     end
 end
-# Convenience method for users to test a single object
-test(T::Type{<:Interface}, obj; kw...) =
-    test(T, typeof(obj), TestObjectWrapper((obj,)); kw...)
 
 function _test(tests::NamedTuple{K}, objs::TestObjectWrapper) where K
     map(keys(tests), values(tests)) do k, v
diff --git a/test/runtests.jl b/test/runtests.jl
index 27970e3..aea9d6d 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,5 +1,8 @@
 using Interfaces
 using Test
+using Aqua
+
+Aqua.test_all(Interfaces)
 
 module Animals