Format dates

l10n/src/lib.rs

@@ -121,13 +121,20 @@ impl L10N {
         }
     */
 
-    fn format_date(
+    fn format_date(&self, date: NaiveDate, date_style: length::Date) -> String {
-        &self,
+        let formatter = icu::datetime::DateFormatter::try_new_with_length(
-        time: NaiveDate,
+            &DataLocale::from(&self.locale),
-        date_style: length::Date,
+            date_style,
-        time_style: length::Time,
+        )
-    ) -> String {
+        .unwrap();
-        unimplemented!()
+        let icu_date: icu::calendar::Date<icu::calendar::Gregorian> =
+            icu::calendar::Date::try_new_gregorian_date(
+                date.year(),
+                date.month().try_into().unwrap(),
+                date.day().try_into().unwrap(),
+            )
+            .unwrap();
+        formatter.format_to_string(&icu_date.to_any()).unwrap()
     }
 
     fn format_f64(&self, value: f64) -> String {
@@ -172,7 +179,20 @@ impl From<DateTime> for icu::calendar::DateTime<icu::calendar::Gregorian> {
 mod tests {
     use super::*;
 
-    fn reftime() -> DateTime {
+    fn ref_l10n() -> L10N {
+        let mut l10n = L10N::default();
+        // Make sure we know the locale before the test begins. Some systems, such as my own, are
+        // not actually in English.
+        l10n.set_locale("en-US".to_owned());
+        l10n.set_timezone(chrono_tz::US::Eastern);
+        l10n
+    }
+
+    fn ref_date() -> NaiveDate {
+        NaiveDate::from_ymd_opt(2006, 1, 2).unwrap()
+    }
+
+    fn ref_time() -> DateTime {
         NaiveDate::from_ymd_opt(2006, 1, 2)
             .unwrap()
             .and_hms_opt(3, 4, 5)
@@ -184,12 +204,8 @@ mod tests {
 
     #[test]
     fn it_formats_a_time_in_utc() {
-        let mut l10n = L10N::default();
+        let mut l10n = ref_l10n();
-        // Make sure we know the locale before the test begins. Some systems, such as my own, are
+        let now = ref_time();
-        // not actually in English.
-        l10n.set_locale("en-US".to_owned());
-        l10n.set_timezone(chrono_tz::US::Eastern);
-        let now = reftime();
 
         // 202f is the code-point for a narrow non-breaking space. Presumably this is used in
         // particular to ensure that the am/pm marker doesn't get split off from the time
@@ -207,12 +223,8 @@ mod tests {
 
     #[test]
     fn it_formats_a_time_in_the_current_zone() {
-        let mut l10n = L10N::default();
+        let mut l10n = ref_l10n();
-        // Make sure we know the locale before the test begins. Some systems, such as my own, are
+        let now = ref_time();
-        // not actually in English.
-        l10n.set_locale("en-US".to_owned());
-        l10n.set_timezone(chrono_tz::US::Eastern);
-        let now = reftime();
 
         // 202f is the code-point for a narrow non-breaking space. Presumably this is used in
         // particular to ensure that the am/pm marker doesn't get split off from the time
@@ -228,6 +240,23 @@ mod tests {
         );
     }
 
+    #[test]
+    fn it_formats_dates() {
+        let mut l10n = ref_l10n();
+        let today = ref_date();
+
+        assert_eq!(
+            l10n.format_date(today.clone(), length::Date::Long),
+            "January 2, 2006"
+        );
+
+        l10n.set_locale("eo-EO".to_owned());
+        assert_eq!(
+            l10n.format_date(today.clone(), length::Date::Long),
+            "2006-Januaro-02"
+        );
+    }
+
     #[test]
     fn it_formats_a_number_according_to_locale() {
         unimplemented!()