Fix Date param binding (#628)

When `BindStyledParameterWithLocation` is used with a Date param,
`UnmarshalText` of the `Date`'s underlying `time.Time` was called.
This would result in an error, because the `DateFormat` `2016-01-02`
is not used by `time.Time`'s `UnmarshalText`. This commit adds an
override to `Date` to make the binding work.

Author: hslatman

date.go

@@ -32,3 +32,12 @@ func (d *Date) UnmarshalJSON(data []byte) error {
 func (d Date) String() string {
 	return d.Time.Format(DateFormat)
 }
+
+func (d *Date) UnmarshalText(data []byte) error {
+	parsed, err := time.Parse(DateFormat, string(data))
+	if err != nil {
+		return err
+	}
+	d.Time = parsed
+	return nil
+}

date_test.go

@@ -52,3 +52,14 @@ func TestDate_Stringer(t *testing.T) {
 		assert.Equal(t, "2019-04-01", fmt.Sprintf("%v", d))
 	})
 }
+
+func TestDate_UnmarshalText(t *testing.T) {
+	testDate := time.Date(2022, 6, 14, 0, 0, 0, 0, time.UTC)
+	value := []byte("2022-06-14")
+
+	date := Date{}
+	err := date.UnmarshalText(value)
+
+	assert.NoError(t, err)
+	assert.Equal(t, testDate, date.Time)
+}