From da9283d5e5703772cb7cf39ecdea2280746af968 Mon Sep 17 00:00:00 2001
From: Milan Bouchet-Valat <nalimilan@club.fr>
Date: Thu, 7 May 2020 11:18:20 +0200
Subject: [PATCH] Always return CategoricalArray names when input is
 CategoricalArray

Previously this was the case only when mixing a `CategoricalArray` with another column,
as the specialized `CategoricalArray` method used `levels`.
---
 src/freqtable.jl  | 3 ++-
 test/freqtable.jl | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/freqtable.jl b/src/freqtable.jl
index f7e5632..f3e7fbd 100644
--- a/src/freqtable.jl
+++ b/src/freqtable.jl
@@ -146,7 +146,8 @@ function _freqtable(x::NTuple{n, AbstractCategoricalVector}, skipmissing::Bool =
     len = map(length, x)
     allowsmissing = map(v -> eltype(v) >: Missing, x)
     lev = map(x) do v
-        eltype(v) >: Missing && !skipmissing ? [levels(v); missing] : allowmissing(levels(v))
+        l = eltype(v) >: Missing && !skipmissing ? [levels(v); missing] : levels(v)
+        CategoricalArray{eltype(v)}(l)
     end
     dims = map(length, lev)
 
diff --git a/test/freqtable.jl b/test/freqtable.jl
index 0a39810..13367a6 100644
--- a/test/freqtable.jl
+++ b/test/freqtable.jl
@@ -164,11 +164,14 @@ for docat in [false, true]
                   0 5
                   1 6]
     @test names(tab) == [["Iris-setosa", "Iris-versicolor", "Iris-virginica"], [false, true]]
+    @test (names(tab, 2) isa CategoricalArray) == docat
+
     tab = freqtable(iris, :Species, :LongSepal, subset=iris.SepalWidth .< 3.8)
     @test tab == [2 0
                   0 5
                   1 6]
     @test names(tab[1:2, :]) == [["Iris-setosa", "Iris-versicolor"], [false, true]]
+    @test (names(tab, 2) isa CategoricalArray) == docat
     iris_nt = (Species = iris.Species, LongSepal = iris.LongSepal)
     @test freqtable(iris, :Species, :LongSepal) == freqtable(iris_nt, :Species, :LongSepal)