expand min/max with missing to all types (#25403)

Author: JeffBezanson

base/missing.jl

@@ -77,16 +77,22 @@ for f in (:(Base.zero), :(Base.one), :(Base.oneunit))
 end
 
 # Binary operators/functions
-for f in (:(+), :(-), :(*), :(/), :(^),
-          :(div), :(mod), :(fld), :(rem), :(min), :(max))
+for f in (:(+), :(-), :(*), :(/), :(^), :(div), :(mod), :(fld), :(rem))
     @eval begin
         # Scalar with missing
         ($f)(::Missing, ::Missing) = missing
-        ($f)(d::Missing, x::Number) = missing
-        ($f)(d::Number, x::Missing) = missing
+        ($f)(::Missing, ::Number)  = missing
+        ($f)(::Number,  ::Missing) = missing
     end
 end
 
+min(::Missing, ::Missing) = missing
+min(::Missing, ::Any)     = missing
+min(::Any,     ::Missing) = missing
+max(::Missing, ::Missing) = missing
+max(::Missing, ::Any)     = missing
+max(::Any,     ::Missing) = missing
+
 # Rounding and related functions
 for f in (:(ceil), :(floor), :(round), :(trunc))
     @eval begin

test/missing.jl

@@ -77,6 +77,15 @@ end
         @test ismissing(f(1, missing))
         @test ismissing(f(missing, 1))
     end
+
+    @test ismissing(min(missing, missing))
+    @test ismissing(max(missing, missing))
+    for f in [min, max]
+        for arg in ["", "a", 1, -1.0, [2]]
+            @test ismissing(f(missing, arg))
+            @test ismissing(f(arg, missing))
+        end
+    end
 end
 
 @testset "bit operators" begin