Add date/time argument type. (#9817)

* Add date/time argument type.
* Add an argument to select which time formats are valid.
* Increase minimum date for epoch timestamps to avoid ambiguity.

command/base_flags_test.go

@@ -0,0 +1,115 @@
+package command
+
+import (
+	"testing"
+	"time"
+)
+
+func Test_TimeParsing(t *testing.T) {
+	var zeroTime time.Time
+
+	testCases := []struct {
+		Input    string
+		Formats  TimeFormat
+		Valid    bool
+		Expected time.Time
+	}{
+		{
+			"2020-08-24",
+			TimeVar_TimeOrDay,
+			true,
+			time.Date(2020, 8, 24, 0, 0, 0, 0, time.UTC),
+		},
+		{
+			"2099-09",
+			TimeVar_TimeOrDay,
+			false,
+			zeroTime,
+		},
+		{
+			"2099-09",
+			TimeVar_TimeOrDay | TimeVar_Month,
+			true,
+			time.Date(2099, 9, 1, 0, 0, 0, 0, time.UTC),
+		},
+		{
+			"2021-01-02T03:04:05-02:00",
+			TimeVar_TimeOrDay,
+			true,
+			time.Date(2021, 1, 2, 5, 4, 5, 0, time.UTC),
+		},
+		{
+			"2021-01-02T03:04:05",
+			TimeVar_TimeOrDay,
+			false, // Missing timezone not supported
+			time.Date(2021, 1, 2, 3, 4, 5, 0, time.UTC),
+		},
+		{
+			"2021-01-02T03:04:05+02:00",
+			TimeVar_TimeOrDay,
+			true,
+			time.Date(2021, 1, 2, 1, 4, 5, 0, time.UTC),
+		},
+		{
+			"1598313593",
+			TimeVar_TimeOrDay,
+			true,
+			time.Date(2020, 8, 24, 23, 59, 53, 0, time.UTC),
+		},
+		{
+			"2037",
+			TimeVar_TimeOrDay,
+			false,
+			zeroTime,
+		},
+		{
+			"20201212",
+			TimeVar_TimeOrDay,
+			false,
+			zeroTime,
+		},
+		{
+			"9999999999999999999999999999999999999999999999",
+			TimeVar_TimeOrDay,
+			false,
+			zeroTime,
+		},
+		{
+			"2021-13-02T03:04:05-02:00",
+			TimeVar_TimeOrDay,
+			false,
+			zeroTime,
+		},
+		{
+			"2021-12-02T24:04:05+00:00",
+			TimeVar_TimeOrDay,
+			false,
+			zeroTime,
+		},
+		{
+			"2021-01-02T03:04:05.234567890Z",
+			TimeVar_TimeOrDay,
+			true,
+			time.Date(2021, 1, 2, 3, 4, 5, 234567890, time.UTC),
+		},
+	}
+
+	for _, tc := range testCases {
+		var result time.Time
+		timeVal := newTimeValue(zeroTime, &result, false, tc.Formats)
+		err := timeVal.Set(tc.Input)
+		if err == nil && !tc.Valid {
+			t.Errorf("Time %q parsed without error as %v, but is not valid", tc.Input, result)
+			continue
+		}
+		if err != nil {
+			if tc.Valid {
+				t.Errorf("Time %q parsed as error, but is valid", tc.Input)
+			}
+			continue
+		}
+		if !tc.Expected.Equal(result) {
+			t.Errorf("Time %q parsed incorrectly, expected %v but got %v", tc.Input, tc.Expected.UTC(), result.UTC())
+		}
+	}
+}