Add a test for empty enums.

src/EnumX.jl

@@ -132,7 +132,7 @@ function Base.show(io::IO, ::MIME"text/plain", ::Base.Type{E}) where E <: Enum
     mx = maximum(x -> textwidth(x.first), stringmap; init = 0)
     print(iob,
         "Enum type $(nameof(parentmodule(E))).$(nameof(E)) <: ",
-        "Enum{$(Base.Enums.basetype(E))} with $(n) instance$(n == 1 ? "" : "s"):"
+        "Enum{$(Base.Enums.basetype(E))} with $(n) instance$(n == 1 ? "" : "s")$(n>0 ? ":" : "")"
     )
     for (k, v) in stringmap
         print(iob, "\n ", rpad(k, mx), " = $(v)")

test/runtests.jl

@@ -213,7 +213,6 @@ end
 @test FruitT.Apple === FruitT.Typ(0)
 
 let io = IOBuffer()
-    io = IOBuffer()
     show(io, "text/plain", FruitT.Typ)
     str = String(take!(io))
     @test str == "Enum type FruitT.Typ <: Enum{Int32} with 2 instances:\n FruitT.Apple  = 0\n FruitT.Banana = 1"
@@ -235,4 +234,17 @@ catch err
     @test err.msg == "instance name Fruit.Apple reserved for the Enum typename."
 end
 
+
+# Empty enum
+@enumx FruitEmpty
+@test instances(FruitEmpty.T) == ()
+let io = IOBuffer()
+    show(io, "text/plain", FruitEmpty.T)
+    str = String(take!(io))
+    @test str == "Enum type FruitEmpty.T <: Enum{Int32} with 0 instances"
+end
+
+@enumx T=Typ FruitEmptyT
+@test instances(FruitEmptyT.Typ) == ()
+
 end # testset