fix(core): serialize duration as strings

Fixes #5615

Since Jackson 2.10, to serialize duration as string we need to switch WRITE_DURATIONS_AS_TIMESTAMPS off as it no longuer use WRITE_DATES_AS_TIMESTAMPS.
I tested and an old flow with a duration as timestamp is still readable so this is a backward compatible change.

But for the State duration, we still need to serialize it as a number as the database expect a number

core/src/main/java/io/kestra/core/models/flows/State.java

@@ -1,8 +1,12 @@
 package io.kestra.core.models.flows;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.datatype.jsr310.ser.DurationSerializer;
+import com.fasterxml.jackson.datatype.jsr310.util.DurationUnitConverter;
 import io.micronaut.core.annotation.Introspected;
 import lombok.Value;
 import lombok.extern.slf4j.Slf4j;
@@ -84,10 +88,11 @@ public State reset() {
     }
 
     @JsonProperty(access = JsonProperty.Access.READ_ONLY)
+    @JsonFormat(shape = JsonFormat.Shape.NUMBER_INT) // force serialization as timestamp as the database column is using a number
     public Duration getDuration() {
         return Duration.between(
             this.histories.getFirst().getDate(),
-            this.histories.size() > 1 ? this.histories.get(this.histories.size() - 1).getDate() : Instant.now()
+            this.histories.size() > 1 ? this.histories.getLast().getDate() : Instant.now()
         );
     }
 

core/src/main/java/io/kestra/core/serializers/JacksonMapper.java

@@ -121,6 +121,7 @@ public static ObjectMapper ofIon() {
     private static ObjectMapper configure(ObjectMapper mapper) {
         return mapper
             .configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)
+            .configure(SerializationFeature.WRITE_DURATIONS_AS_TIMESTAMPS, false)
             .setSerializationInclusion(JsonInclude.Include.NON_NULL)
             .registerModule(new JavaTimeModule())
             .registerModule(new Jdk8Module())

core/src/test/java/io/kestra/plugin/core/kv/SetTest.java

@@ -209,8 +209,7 @@ void typeSpecified() throws Exception {
         assertThat(kv.getValue(TEST_KEY).get().value(), is(Instant.parse("2023-05-02T01:02:03Z")));
 
         set.toBuilder().value("P1DT5S").kvType(KVType.DURATION).build().run(runContext);
-        // TODO Hack meanwhile we handle duration serialization as currently they are stored as bigint...
-        assertThat((long) Double.parseDouble(kv.getValue(TEST_KEY).get().value().toString()), is(Duration.ofDays(1).plus(Duration.ofSeconds(5)).toSeconds()));
+        assertThat(kv.getValue(TEST_KEY).get().value(), is(Duration.ofDays(1).plus(Duration.ofSeconds(5))));
 
         set.toBuilder().value("[{\"some\":\"value\"},{\"another\":\"value\"}]").kvType(KVType.JSON).build().run(runContext);
         assertThat(kv.getValue(TEST_KEY).get().value(), is(List.of(Map.of("some", "value"), Map.of("another", "value"))));