testing: Add tests for Lua dates

Also fix a timezone bug discovered while testing

internal/handlers/date_lua.go

@@ -63,9 +63,10 @@ func luaWeakCheckTableFieldInt(L *lua.LState, T *lua.LTable, n int, name string,
 }
 
 func luaDateNew(L *lua.LState) int {
+	// TODO make this track the user's timezone
 	v := L.Get(1)
 	if s, ok := v.(lua.LString); ok {
-		date, err := time.Parse(timeFormat, s.String())
+		date, err := time.ParseInLocation(timeFormat, s.String(), time.Local)
 		if err != nil {
 			L.ArgError(1, "error parsing date string: "+err.Error())
 			return 0

internal/handlers/date_lua_test.go

@@ -0,0 +1,31 @@
+package handlers_test
+
+import (
+	"testing"
+)
+
+func TestLuaDates(t *testing.T) {
+	RunWith(t, &data[0], func(t *testing.T, d *TestData) {
+		simpleLuaTest(t, d.clients[0], []LuaTest{
+			{"Year", "return date.new('0009-01-03').Year", "9"},
+			{"Month", "return date.new('3999-02-01').Month", "2"},
+			{"Day", "return date.new('1997-12-31').Day", "31"},
+			{"__tostring", "return date.new('0997-12-01')", "0997-12-01"},
+			{"__tostring 2", "return date.new(997, 12, 1)", "0997-12-01"},
+			{"__tostring 3", "return date.new({year=997, month=12, day=1})", "0997-12-01"},
+			{"__eq", "return date.new('2017-10-05') == date.new(2017, 10, 5)", "true"},
+			{"(not) __eq", "return date.new('0997-12-01') == date.new('1997-12-01')", "false"},
+			{"__lt", "return date.new('0997-12-01') < date.new('1997-12-01')", "true"},
+			{"(not) __lt", "return date.new('2001-12-01') < date.new('1997-12-01')", "false"},
+			{"not __lt self", "return date.new('2001-12-01') < date.new('2001-12-01')", "false"},
+			{"__le", "return date.new('0997-12-01') <= date.new('1997-12-01')", "true"},
+			{"(not) __le", "return date.new(2001, 12, 1) <= date.new('1997-12-01')", "false"},
+			{"__le self", "return date.new('2001-12-01') <= date.new(2001, 12, 1)", "true"},
+			{"__add", "return date.new('2001-12-30') + date.new({year=0, month=0, day=1})", "2001-12-31"},
+			{"__add", "return date.new('2001-12-30') + date.new({year=0, month=0, day=2})", "2002-01-01"},
+			{"__sub", "return date.new('2001-12-30') - date.new({year=1, month=1, day=1})", "2000-11-29"},
+			{"__sub", "return date.new('2058-03-01') - date.new({year=0, month=0, day=1})", "2058-02-28"},
+			{"__sub", "return date.new('2058-03-31') - date.new({year=0, month=1, day=0})", "2058-02-28"},
+		})
+	})
+}