Merge pull request #11 from JuliaDiff/aa/more-tests

Add some more tests

test/runtests.jl

@@ -1,7 +1,81 @@
 # TODO: more tests!
 
 using ChainRules, Test
-using ChainRules: One, Zero, rrule, frule, extern, cast, accumulate, accumulate!, store!
+using ChainRules: rrule, frule, extern, accumulate, accumulate!, store!, @scalar_rule,
+                  Wirtinger, wirtinger_primal, wirtinger_conjugate, add_wirtinger, mul_wirtinger,
+                  Zero, add_zero, mul_zero, One, add_one, mul_one,
+                  Casted, cast, add_casted, mul_casted
+using Base.Broadcast: broadcastable
+
+cool(x) = x + 1
+@testset "frule and rrule" begin
+    @test frule(cool, 1) === nothing
+    @test rrule(cool, 1) === nothing
+    ChainRules.@scalar_rule(Main.cool(x), one(x))
+    frx, fr = frule(cool, 1)
+    @test frx == 2
+    @test fr(1) == 1
+    rrx, rr = rrule(cool, 1)
+    @test rrx == 2
+    @test rr(1) == 1
+end
+
+@testset "iterating rules" begin
+    _, rule = frule(+, 1)
+    i = 0
+    for r in rule
+        @test r === rule
+        i += 1
+    end
+    @test i == 1  # rules only iterate once, yielding themselves
+end
+
+@testset "Differentials" begin
+    @testset "Wirtinger" begin
+        w = Wirtinger(1+1im, 2+2im)
+        @test wirtinger_primal(w) == 1+1im
+        @test wirtinger_conjugate(w) == 2+2im
+        @test add_wirtinger(w, w) == Wirtinger(2+2im, 4+4im)
+        # TODO: other add_wirtinger methods stack overflow
+        @test_throws ErrorException mul_wirtinger(w, w)
+        @test_throws ErrorException extern(w)
+        for x in w
+            @test x === w
+        end
+        @test broadcastable(w) == w
+        @test_throws ErrorException conj(w)
+    end
+    @testset "Zero" begin
+        z = Zero()
+        @test extern(z) === false
+        @test add_zero(z, z) == z
+        @test add_zero(z, 1) == 1
+        @test add_zero(1, z) == 1
+        @test mul_zero(z, z) == z
+        @test mul_zero(z, 1) == z
+        @test mul_zero(1, z) == z
+        for x in z
+            @test x === z
+        end
+        @test broadcastable(z) isa Ref{Zero}
+        @test conj(z) == z
+    end
+    @testset "One" begin
+        o = One()
+        @test extern(o) === true
+        @test add_one(o, o) == 2
+        @test add_one(o, 1) == 2
+        @test add_one(1, o) == 2
+        @test mul_one(o, o) == o
+        @test mul_one(o, 1) == 1
+        @test mul_one(1, o) == 1
+        for x in o
+            @test x === o
+        end
+        @test broadcastable(o) isa Ref{One}
+        @test conj(o) == o
+    end
+end
 
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 ##### `*(x, y)`