fix(core): Schedule trigger cannot have an interval (#2008)

close #2005

core/src/main/java/io/kestra/core/models/triggers/types/Schedule.java

@@ -21,6 +21,7 @@
 import io.kestra.core.runners.RunnerUtils;
 import io.kestra.core.services.ConditionService;
 import io.kestra.core.validations.CronExpression;
+import io.swagger.v3.oas.annotations.Hidden;
 import io.swagger.v3.oas.annotations.media.Schema;
 import lombok.*;
 import lombok.experimental.SuperBuilder;
@@ -35,6 +36,7 @@
 import java.util.Optional;
 import javax.validation.Valid;
 import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Null;
 
 @SuperBuilder
 @ToString
@@ -143,7 +145,9 @@ public class Schedule extends AbstractTrigger implements PollingTriggerInterface
     @PluginProperty
     private ScheduleBackfill backfill;
 
+    @Schema(hidden = true)
     @Builder.Default
+    @Null
     private final Duration interval = null;
 
     @Valid

core/src/test/java/io/kestra/core/validations/ScheduleTest.java

@@ -33,4 +33,19 @@ void cronValidation()  {
         assertThat(modelValidator.isValid(build).isPresent(), is(true));
         assertThat(modelValidator.isValid(build).get().getMessage(), containsString("backfill and lateMaximumDelay are incompatible options"));
     }
+
+    @Test
+    void intervalValidation() {
+        Schedule build = Schedule.builder()
+            .id(IdUtils.create())
+            .type(Schedule.class.getName())
+            .cron("* * * * *")
+            .interval(Duration.ofSeconds(5))
+            .build();
+
+
+        assertThat(modelValidator.isValid(build).isPresent(), is(true));
+        assertThat(modelValidator.isValid(build).get().getMessage(), containsString("interval: must be null"));
+
+    }
 }