feat(common): support ICU standard "stand alone day of week" with DatePipe (#40766)

This commit adds support for Finnish full date formatting,
as well as `c/cc/ccc/cccc/ccccc/cccccc` date formats in the `DatePipe`.

Fixes #26922

PR Close #40766

goldens/size-tracking/integration-payloads.json

@@ -30,7 +30,7 @@
     "master": {
       "uncompressed": {
         "runtime-es2015": 1485,
-        "main-es2015": 136703,
+        "main-es2015": 137236,
         "polyfills-es2015": 37641
       }
     }

packages/common/src/i18n/format_date.ts

@@ -13,7 +13,7 @@ export const ISO8601_DATE_REGEX =
 //    1        2       3         4          5          6          7          8  9     10      11
 const NAMED_FORMATS: {[localeId: string]: {[format: string]: string}} = {};
 const DATE_FORMATS_SPLIT =
-    /((?:[^GyYMLwWdEabBhHmsSzZO']+)|(?:'(?:[^']|'')*')|(?:G{1,5}|y{1,4}|Y{1,4}|M{1,5}|L{1,5}|w{1,2}|W{1}|d{1,2}|E{1,6}|a{1,5}|b{1,5}|B{1,5}|h{1,2}|H{1,2}|m{1,2}|s{1,2}|S{1,3}|z{1,4}|Z{1,5}|O{1,4}))([\s\S]*)/;
+    /((?:[^BEGHLMOSWYZabcdhmswyz']+)|(?:'(?:[^']|'')*')|(?:G{1,5}|y{1,4}|Y{1,4}|M{1,5}|L{1,5}|w{1,2}|W{1}|d{1,2}|E{1,6}|c{1,6}|a{1,5}|b{1,5}|B{1,5}|h{1,2}|H{1,2}|m{1,2}|s{1,2}|S{1,3}|z{1,4}|Z{1,5}|O{1,4}))([\s\S]*)/;
 
 enum ZoneWidth {
   Short,
@@ -445,7 +445,7 @@ const DATE_FORMATS: {[format: string]: DateFormatter} = {};
 // Based on CLDR formats:
 // See complete list: http://www.unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table
 // See also explanations: http://cldr.unicode.org/translation/date-time
-// TODO(ocombe): support all missing cldr formats: Y, U, Q, D, F, e, c, j, J, C, A, v, V, X, x
+// TODO(ocombe): support all missing cldr formats: U, Q, D, F, e, j, J, C, A, v, V, X, x
 function getDateFormatter(format: string): DateFormatter|null {
   if (DATE_FORMATS[format]) {
     return DATE_FORMATS[format];
@@ -557,6 +557,26 @@ function getDateFormatter(format: string): DateFormatter|null {
       formatter = dateGetter(DateType.Date, 2);
       break;
 
+    // Day of the Week StandAlone (1, 1, Mon, Monday, M, Mo)
+    case 'c':
+    case 'cc':
+      formatter = dateGetter(DateType.Day, 1);
+      break;
+    case 'ccc':
+      formatter =
+          dateStrGetter(TranslationType.Days, TranslationWidth.Abbreviated, FormStyle.Standalone);
+      break;
+    case 'cccc':
+      formatter = dateStrGetter(TranslationType.Days, TranslationWidth.Wide, FormStyle.Standalone);
+      break;
+    case 'ccccc':
+      formatter =
+          dateStrGetter(TranslationType.Days, TranslationWidth.Narrow, FormStyle.Standalone);
+      break;
+    case 'cccccc':
+      formatter = dateStrGetter(TranslationType.Days, TranslationWidth.Short, FormStyle.Standalone);
+      break;
+
     // Day of the Week
     case 'E':
     case 'EE':

packages/common/src/pipes/date_pipe.ts

@@ -86,6 +86,11 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
  *  |                     | EEEE        | Wide                                                          | Tuesday                                                    |
  *  |                     | EEEEE       | Narrow                                                        | T                                                          |
  *  |                     | EEEEEE      | Short                                                         | Tu                                                         |
+ *  | Week day standalone | c, cc       | Numeric: 1 digit                                              | 2                                                          |
+ *  |                     | ccc         | Abbreviated                                                   | Tue                                                        |
+ *  |                     | cccc        | Wide                                                          | Tuesday                                                    |
+ *  |                     | ccccc       | Narrow                                                        | T                                                          |
+ *  |                     | cccccc      | Short                                                         | Tu                                                         |
  *  | Period              | a, aa & aaa | Abbreviated                                                   | am/pm or AM/PM                                             |
  *  |                     | aaaa        | Wide (fallback to `a` when missing)                           | ante meridiem/post meridiem                                |
  *  |                     | aaaaa       | Narrow                                                        | a/p                                                        |

packages/common/test/i18n/format_date_spec.ts

@@ -9,6 +9,7 @@ import localeAr from '@angular/common/locales/ar';
 import localeDe from '@angular/common/locales/de';
 import localeEn from '@angular/common/locales/en';
 import localeEnExtra from '@angular/common/locales/extra/en';
+import localeFi from '@angular/common/locales/fi';
 import localeHu from '@angular/common/locales/hu';
 import localeSr from '@angular/common/locales/sr';
 import localeTh from '@angular/common/locales/th';
@@ -78,6 +79,7 @@ describe('Format date', () => {
       ɵregisterLocaleData(localeSr);
       ɵregisterLocaleData(localeTh);
       ɵregisterLocaleData(localeAr);
+      ɵregisterLocaleData(localeFi);
     });
 
     afterAll(() => ɵunregisterLocaleData());
@@ -116,6 +118,12 @@ describe('Format date', () => {
         W: '3',
         d: '15',
         dd: '15',
+        c: '1',
+        cc: '1',
+        ccc: 'Mon',
+        cccc: 'Monday',
+        ccccc: 'M',
+        cccccc: 'Mo',
         E: 'Mon',
         EE: 'Mon',
         EEE: 'Mon',
@@ -178,6 +186,12 @@ describe('Format date', () => {
         W: '1',
         d: '1',
         dd: '01',
+        c: '4',
+        cc: '4',
+        ccc: 'Thu',
+        cccc: 'Thursday',
+        ccccc: 'T',
+        cccccc: 'Th',
         E: 'Thu',
         EE: 'Thu',
         EEE: 'Thu',
@@ -427,5 +441,10 @@ describe('Format date', () => {
       expect(formatDate('0001-01-11', 'YYYY', ɵDEFAULT_LOCALE_ID)).toEqual('0001');
       expect(formatDate('0000-01-11', 'YYYY', ɵDEFAULT_LOCALE_ID)).toEqual('0000');
     });
+
+    // https://github.com/angular/angular/issues/26922
+    it('should support fullDate in finnish, which uses standalone week day', () => {
+      expect(formatDate(date, 'fullDate', 'fi')).toMatch('maanantai 15. kesäkuuta 2015');
+    });
   });
 });