fix(abc:st): correct default value of date type (#1823)

Author: cipchk

packages/abc/st/st-data-source.ts

@@ -239,7 +239,10 @@ export class STDataSource {
           text = this.currencySrv.format(value, col.currency?.format);
           break;
         case 'date':
-          text = value === col.default ? col.default : this.datePipe.transform(value, col.dateFormat);
+          text =
+            value == null || value === col.default || (typeof value === 'number' && value <= 0)
+              ? col.default
+              : this.datePipe.transform(value, col.dateFormat);
           break;
         case 'yn':
           text = this.ynPipe.transform(value === col.yn!.truth, col.yn!.yes!, col.yn!.no!, col.yn!.mode!, false);

packages/abc/st/test/st-data-source.spec.ts

@@ -791,6 +791,14 @@ describe('abc: table: data-souce', () => {
             done();
           });
         });
+        it('should be return default value when is 0 timestamp', done => {
+          options.columns[0] = { index: 'date', type: 'date', default: '-' } as _STColumn;
+          options.data = [{ date: 0 }, { date: new Date() }];
+          srv.process(options).subscribe(res => {
+            expect(res.list[0]._values[0].text).toBe('-');
+            done();
+          });
+        });
       });
       it('via yn', done => {
         options.columns[0].type = 'yn';