Allow open-ended ranges

lib/pg_ranges/numrange.ex

@@ -92,6 +92,8 @@ defmodule PgRanges.NumRange do
     struct!(__MODULE__, fields)
   end
 
+  defp to_decimal(value)
+  defp to_decimal(nil), do: nil
   defp to_decimal(value) when is_float(value), do: Decimal.from_float(value)
   defp to_decimal(value), do: Decimal.new(value)
 end

lib/pg_ranges/tstzrange.ex

@@ -29,11 +29,20 @@ defmodule PgRanges.TstzRange do
   @impl true
   def new(lower, upper, opts \\ []) do
     time_zone_database = Keyword.get(opts, :time_zone_database, Calendar.get_time_zone_database())
-    {:ok, lower} = DateTime.shift_zone(lower, "Etc/UTC", time_zone_database)
-    {:ok, upper} = DateTime.shift_zone(upper, "Etc/UTC", time_zone_database)
+
+    lower = shift_to_utc(lower, time_zone_database)
+    upper = shift_to_utc(upper, time_zone_database)
 
     fields = Keyword.merge(opts, lower: lower, upper: upper)
 
     struct!(__MODULE__, fields)
   end
+
+  defp shift_to_utc(date_time, time_zone_database)
+  defp shift_to_utc(nil, _time_zone_database), do: nil
+
+  defp shift_to_utc(date_time, time_zone_database) do
+    {:ok, date_time} = DateTime.shift_zone(date_time, "UTC", time_zone_database)
+    date_time
+  end
 end

test/pg_ranges_test.exs

@@ -14,7 +14,7 @@ defmodule PgRanges.PgRangesTest do
     NumRange
   }
 
-  setup do
+  test "querying" do
     date_range = DateRange.new(~D[2018-04-21], ~D[2018-04-22])
     ts_range = TsRange.new(~N[2018-04-21 15:00:00], ~N[2018-04-22 01:00:00])
 
@@ -28,7 +28,7 @@ defmodule PgRanges.PgRangesTest do
     int8_range = Int8Range.new(0, 1_000_000_000)
     num_range = NumRange.new(0, 9.9, upper_inclusive: true)
 
-    {:ok, m} =
+    {:ok, _model} =
       Model.changeset(%Model{}, %{
         date: date_range,
         ts: ts_range,
@@ -39,15 +39,22 @@ defmodule PgRanges.PgRangesTest do
       })
       |> Repo.insert()
 
-    {:ok, model: m}
-  end
-
-  test "querying" do
-    range = Int4Range.new(1, 4)
+    search_range = Int4Range.new(1, 4)
 
     models =
-      Repo.all(from(m in Model, where: fragment("? @> ?", m.int4, type(^range, Int4Range))))
+      Repo.all(
+        from(m in Model, where: fragment("? @> ?", m.int4, type(^search_range, Int4Range)))
+      )
 
     assert length(models) == 1
   end
+
+  test "can create open ended ranges" do
+    assert %DateRange{lower: nil, upper: nil} = DateRange.new(nil, nil)
+    assert %TsRange{lower: nil, upper: nil} = TsRange.new(nil, nil)
+    assert %TstzRange{lower: nil, upper: nil} = TstzRange.new(nil, nil)
+    assert %Int4Range{lower: nil, upper: nil} = Int4Range.new(nil, nil)
+    assert %Int8Range{lower: nil, upper: nil} = Int8Range.new(nil, nil)
+    assert %NumRange{lower: nil, upper: nil} = NumRange.new(nil, nil)
+  end
 end