Merge pull request #37834 from sostock/compoundperiodhash

Fix hashing of Dates.CompoundPeriod

Author: quinnj

stdlib/Dates/src/periods.jl

@@ -472,6 +472,14 @@ Base.hash(x::Year, h::UInt) = hash(12 * value(x), h + otherperiod_seed(x))
 Base.hash(x::Quarter, h::UInt) = hash(3 * value(x), h + otherperiod_seed(x))
 Base.hash(x::Month, h::UInt) = hash(value(x), h + otherperiod_seed(x))
 
+function Base.hash(x::CompoundPeriod, h::UInt)
+    isempty(x.periods) && return hash(0, h + zero_or_fixedperiod_seed)
+    for p in x.periods
+        h = hash(p, h)
+    end
+    return h
+end
+
 Base.isless(x::FixedPeriod, y::OtherPeriod) = throw(MethodError(isless, (x, y)))
 Base.isless(x::OtherPeriod, y::FixedPeriod) = throw(MethodError(isless, (x, y)))
 

stdlib/Dates/test/periods.jl

@@ -477,6 +477,14 @@ end
         end
     end
 end
+@testset "Hashing for CompoundPeriod (#37447)" begin
+    periods = [Dates.Year(0), Dates.Minute(0), Dates.Second(0), Dates.CompoundPeriod(),
+               Dates.Minute(2), Dates.Second(120), Dates.CompoundPeriod(Dates.Minute(2)),
+               Dates.CompoundPeriod(Dates.Second(120)), Dates.CompoundPeriod(Dates.Minute(1), Dates.Second(60))]
+    for x = periods, y = periods
+        @test isequal(x,y) == (hash(x) == hash(y))
+    end
+end
 
 @testset "#30832" begin
     @test Dates.toms(Dates.Second(1) + Dates.Nanosecond(1)) == 1e3