Check and fix the sumsquares demo

src/CheckedArithmetic.jl

@@ -106,12 +106,16 @@ macro check(expr)
     for i = 2:length(expr.args)
         safeexpr.args[i] = Expr(:call, :(CheckedArithmetic.safearg), expr.args[i])
     end
-    return esc(quote
-        val = $expr
-        valcmp = CheckedArithmetic.safeconvert(typeof(val), $safeexpr)
-        @test val == valcmp
-        return val
-    end)
+    return quote
+        local val = $(esc(expr))
+        local valcmp = CheckedArithmetic.safeconvert(typeof(val), $(esc(safeexpr)))
+        if ismissing(val) && ismissing(valcmp)
+            val
+        else
+            val == valcmp || error(val, " is not equal to ", valcmp)
+            val
+        end
+    end
 end
 
 """
@@ -172,12 +176,12 @@ safearg(ref::Ref) = Ref(safearg(ref[]))
 safearg(d::Dict) = Dict(safearg(p) for p in d)
 safearg(d::Base.EnvDict) = d
 safearg(d::Base.ImmutableDict) = Base.ImmutableDict(safearg(p) for p in d)
-safearg(d::Iterators.Pairs) = Iterators.Pairs(safearg(p) for p in d)
+safearg(d::Iterators.Pairs) = Iterators.Pairs(safearg(d.data), d.itr)
 safearg(d::IdDict) = IdDict(safearg(p) for p in d)
 safearg(d::WeakKeyDict) = WeakKeyDict(k=>safearg(v) for (k, v) in d)  # do not convert keys
 ## AbstractSets
-safearg(s::Set) = Set(f(x) for x in s)
-safearg(s::Base.IdSet) = Base.IdSet(f(x) for x in s)
+safearg(s::Set) = Set(safearg(x) for x in s)
+safearg(s::Base.IdSet) = Base.IdSet(safearg(x) for x in s)
 safearg(s::BitSet) = s
 
 # Other common types
@@ -243,6 +247,7 @@ Base.@pure accumulatortype(op::Function, T1::Type, T2::Type, T3::Type...) =
     accumulatortype(op, promote_type(T1, T2, T3...))
 Base.@pure accumulatortype(T1::Type, T2::Type, T3::Type...) =
     accumulatortype(*, T1, T2, T3...)
+accumulatortype(::Type{T}) where T = accumulatortype(*, T)
 
 const SignPreserving = Union{typeof(+), typeof(*)}
 const ArithmeticOp = Union{SignPreserving,typeof(-)}

test/runtests.jl

@@ -1,5 +1,5 @@
 using CheckedArithmetic
-using Test
+using Test, Dates
 
 @test isempty(detect_ambiguities(CheckedArithmetic, Base, Core))
 
@@ -8,6 +8,14 @@ using Test
     minus(x, y) = x - y
 end
 
+function sumsquares(A::AbstractArray)
+    s = zero(accumulatortype(eltype(A)))
+    for a in A
+        s += acc(a)^2
+    end
+    return s
+end
+
 @testset "CheckedArithmetic.jl" begin
     @testset "@checked" begin
         @test @checked(abs(Int8(-2))) === Int8(2)
@@ -41,7 +49,7 @@ end
         @test_throws OverflowError minus(0x20, 0x30)
     end
 
-    @testset "check" begin
+    @testset "@check" begin
         @test @check(3+5) == 8
         @test_throws InexactError @check(0xf0+0x15)
         @test @check([3]+[5]) == [8]
@@ -54,10 +62,10 @@ end
         @test @check(times2(Dict("a"=>7))) == Dict("a"=>14)
         @test_throws InexactError @check(times2(Dict("a"=>0xf0)))
         for item in Any["hi", :hi, (3,), (silly="hi",), trues(3), [true], 1:3, 1:2:5,
-                        LinRange(1, 3, 3), StepRangeLen(1.0, 3.0, 3), 0x01:0x03, Ref(2),
+                        LinRange(1, 3, 3), StepRangeLen(1.0, 3.0, 3), 0x01:0x03,
                         pairs((silly="hi",)), Set([1,3]), BitSet(7), nothing, missing,
                         Some(nothing), 'c', MIME("text/plain"), IOBuffer(), r"\d+",
-                        Channel(), CartesianIndex(1, 3), Base.UUID(0), `ls`,
+                        Channel(7), CartesianIndex(1, 3), Base.UUID(0), `ls`,
                         sum, Base, Val(3), Task(()->1), Base.Order.Forward, Timer(0.1),
                         now()]
             @test @check(identity(item)) === item
@@ -69,5 +77,7 @@ end
         @test acc(-, 0x02) === 2
         @test accumulatortype(-, UInt8) === Int
         @test accumulatortype(*, Int16, Float16) === Float64
+
+        @test sumsquares(0x00:0xff) == sumsquares(0:255)
     end
 end