fix: 🐛 Make all adapter constructor parameters optional. Make enUS locale default when no locales provided.

Author: sapozhnikovay

projects/ngx-mat-datefns-date-adapter/src/lib/ngx-mat-datefns-date-adapter.spec.ts

@@ -316,7 +316,7 @@ describe('NgxDateFnsDateAdapter', () => {
 
   it('should throw when attempting to set locale via string without providing NGX_MAT_DATEFNS_LOCALES token', () => {
     expect(() => adapter.setLocale('invalid')).toThrowError(
-      /locales array does not provided or is empty/
+      /locale 'invalid' does not exist in locales array. Add it to the NGX_MAT_DATEFNS_LOCALES token./
     );
   });
 
@@ -643,7 +643,7 @@ describe('NgxDateFnsDateAdapter with NGX_MAT_DATEFNS_LOCALES set', () => {
 
   it('should throw when attempting to set locale without providing it in the NGX_MAT_DATEFNS_LOCALES token', () => {
     expect(() => adapter.setLocale('ru')).toThrowError(
-      /locale \'ru\' does not exist/
+      /locale \'ru\' does not exist in locales array. Add it to the NGX_MAT_DATEFNS_LOCALES token./
     );
   });
 });

projects/ngx-mat-datefns-date-adapter/src/lib/ngx-mat-datefns-date-adapter.ts

@@ -60,26 +60,30 @@ export class NgxDateFnsDateAdapter extends DateAdapter<Date> {
       return localeCodeOrLocale as Locale;
     }
     if (!this.locales || !this.locales.length) {
-      throw new Error('locales array does not provided or is empty');
+      throw new Error('locales array does not provided or is empty. Provide it via the NGX_MAT_DATEFNS_LOCALES token.');
     }
     const locale = this.locales.find(
       (item) => item.code === localeCodeOrLocale
     );
     if (!locale) {
-      throw new Error(`locale '${localeCodeOrLocale}' does not exist`);
+      throw new Error(`locale '${localeCodeOrLocale}' does not exist in locales array. Add it to the NGX_MAT_DATEFNS_LOCALES token.`);
     }
     return locale;
   };
 
   constructor(
-    @Optional() @Inject(MAT_DATE_LOCALE) dateLocale: string,
-    @Inject(NGX_MAT_DATEFNS_LOCALES) private locales: Locale[],
+    @Optional() @Inject(MAT_DATE_LOCALE) dateLocale: string | null,
+    @Optional() @Inject(NGX_MAT_DATEFNS_LOCALES) private locales: Locale[] | null,
     @Optional()
     @Inject(NGX_MAT_DATEFNS_DATE_ADAPTER_OPTIONS)
     private options?: NgxDateFnsDateAdapterOptions
   ) {
     super();
 
+    if (!this.locales || this.locales.length === 0) {
+      this.locales = [enUS];
+    }
+
     try {
       this.setLocale(dateLocale || enUS);
     } catch (err) {