Override Date.prototype.to*String with Intl.DateTimeFormat.format

src/js/i18n.js

Index: src/js/i18n.js
diff --git a/src/js/i18n.js b/src/js/i18n.js
index 18d13db9a2c2f96e88f2c96305486ec7cb933cc9..92c9a80a0b7b5ed4264738e2c7f5001f97a4b1ba 100644
--- a/src/js/i18n.js
+++ b/src/js/i18n.js
@@ -1959,7 +1959,10 @@ var savedObjects = {
   'numberformat': GlobalIntlNumberFormat,
   'dateformatall': GlobalIntlDateTimeFormat,
   'dateformatdate': GlobalIntlDateTimeFormat,
-  'dateformattime': GlobalIntlDateTimeFormat
+  'dateformattime': GlobalIntlDateTimeFormat,
+  'datetostring': GlobalIntlDateTimeFormat,
+  'datetodatestring': GlobalIntlDateTimeFormat,
+  'datetotimestring': GlobalIntlDateTimeFormat,
 };
 
 
@@ -1971,12 +1974,18 @@ var defaultObjects = {
   'dateformatall': UNDEFINED,
   'dateformatdate': UNDEFINED,
   'dateformattime': UNDEFINED,
+  'datetostring': UNDEFINED,
+  'datetodatestring': UNDEFINED,
+  'datetotimestring': UNDEFINED,
 };
 
 function clearDefaultObjects() {
   defaultObjects['dateformatall'] = UNDEFINED;
   defaultObjects['dateformatdate'] = UNDEFINED;
   defaultObjects['dateformattime'] = UNDEFINED;
+  defaultObjects['datetostring'] = UNDEFINED;
+  defaultObjects['datetodatestring'] = UNDEFINED;
+  defaultObjects['datetotimestring'] = UNDEFINED;
 }
 
 var date_cache_version = 0;
@@ -1993,11 +2002,14 @@ function checkDateCacheCurrent() {
 
 /**
  * Returns cached or newly created instance of a given service.
- * We cache only default instances (where no locales or options are provided).
+ * We cache only default instances (where no locales or options are provided)
+ * or overrides of Date.prototype.to{,Date,Time}String for which useCached
+ * is defined.
  */
-function cachedOrNewService(service, locales, options, defaults) {
+function cachedOrNewService(service, locales, options, defaults, useCached) {
   var useOptions = (IS_UNDEFINED(defaults)) ? options : defaults;
-  if (IS_UNDEFINED(locales) && IS_UNDEFINED(options)) {
+  if (!IS_UNDEFINED(useCached) ||
+      (IS_UNDEFINED(locales) && IS_UNDEFINED(options))) {
     checkDateCacheCurrent();
     if (IS_UNDEFINED(defaultObjects[service])) {
       defaultObjects[service] = new savedObjects[service](locales, useOptions);
@@ -2139,7 +2151,8 @@ OverrideFunction(GlobalNumber.prototype, 'toLocaleString', function() {
 /**
  * Returns actual formatted date or fails if date parameter is invalid.
  */
-function toLocaleDateTime(date, locales, options, required, defaults, service) {
+function toLocaleDateTime(date, locales, options, required, defaults, service,
+                          useCached) {
   if (!(date instanceof GlobalDate)) {
     throw %make_type_error(kMethodInvokedOnWrongType, "Date");
   }
@@ -2150,7 +2163,7 @@ function toLocaleDateTime(date, locales, options, required, defaults, service) {
   var internalOptions = toDateTimeOptions(options, required, defaults);
 
   var dateFormat =
-      cachedOrNewService(service, locales, options, internalOptions);
+      cachedOrNewService(service, locales, options, internalOptions, useCached);
 
   return formatDate(dateFormat, date);
 }
@@ -2169,6 +2182,18 @@ OverrideFunction(GlobalDate.prototype, 'toLocaleString', function() {
   }
 );
 
+OverrideFunction(GlobalDate.prototype, 'toString', function() {
+    var options = {
+      weekday: "short", month: "short", year: "numeric", day: "2-digit",
+      hour: "2-digit", minute: "2-digit", second: "2-digit",
+      timeZoneName: "short", hour12: false,
+    };
+
+    return toLocaleDateTime(
+        this, "en-US", options, 'any', 'all', 'datetostring', true);
+  }
+);
+
 
 /**
  * Formats a Date object (this) using locale and options values.
@@ -2183,6 +2208,15 @@ OverrideFunction(GlobalDate.prototype, 'toLocaleDateString', function() {
   }
 );
 
+OverrideFunction(GlobalDate.prototype, 'toDateString', function() {
+    var options = { weekday: "short", month: "short", year: "numeric",
+                    day: "2-digit",};
+
+    return toLocaleDateTime(
+        this, "en-US", options, 'date', 'date', 'datetodatestring', true);
+  }
+);
+
 
 /**
  * Formats a Date object (this) using locale and options values.
@@ -2198,9 +2232,17 @@ OverrideFunction(GlobalDate.prototype, 'toLocaleTimeString', function() {
 );
 
 %FunctionRemovePrototype(FormatDateToParts);
-
 utils.Export(function(to) {
   to.FormatDateToParts = FormatDateToParts;
 });
 
+OverrideFunction(GlobalDate.prototype, 'toTimeString', function() {
+    var options = { hour: "2-digit", minute: "2-digit", second: "2-digit",
+                    timeZoneName: "short", hour12: false};
+
+    return toLocaleDateTime(
+        this, "en-US", options, 'time', 'time', 'datetotimestring', true);
+  }
+);
+
 })