fix(core): allow null val for optional input with default (#11819)

[fhussonnois]

Handles multipart 'null' string as null (no value) for the input

Fixes: #11819

[github-actions]

🐋 Docker image

ghcr.io/kestra-io/kestra-pr:11960

docker run --pull=always --rm -it -p 8080:8080 --user=root -v /var/run/docker.sock:/var/run/docker.sock -v /tmp:/tmp ghcr.io/kestra-io/kestra-pr:11960 server local

🧪 Java Unit Tests

	Tests	Passed ✅	Skipped ⚠️	Failed	Time ⏱
Java Tests Report	3425 ran	3412 ✅	13 ⚠️	0 ❌	52m 59s 96ms

[loicmathieu]

I'm not convinced here as now a String input with the string "null" would be considered a null input which seems wrong to me and is clearly a BC.

A null input should not have any part.

[github-actions]

Tests report quick summary:

totals > tests: 3425, success: 3412, skipped: 13, failed: 0

Project	Status	Success	Skipped	Failed
cli	success ✅	72	0	0
core	success ✅	1601	0	0
executor	success ✅	3	0	0
jdbc	success ✅	10	0	0
jdbc-h2	success ✅	430	0	0
jdbc-mysql	success ✅	432	0	0
jdbc-postgres	success ✅	432	0	0
processor	success ✅	7	0	0
runner-memory	success ✅	1	0	0
scheduler	success ✅	22	0	0
script	success ✅	11	0	0
storage-local	success ✅	62	0	0
webserver	success ✅	337	0	0
worker	success ✅	5	0	0

---

Flaky tests report quick summary:

totals > tests: 22, success: 17, skipped: 2, failed: 3

Project	Status	Success	Skipped	Failed
cli	success ✅	2	0	0
core	failed ❌	2	0	3
jdbc	success ✅	2	0	0
jdbc-h2	success ✅	2	0	0
jdbc-mysql	success ✅	4	0	0
jdbc-postgres	success ✅	4	0	0
scheduler	success ✅	2	0	0
webserver	success ✅	1	0	0

Failed tests:

core > io.kestra.plugin.core.flow.PauseTest > delayFromInput() failed ❌ in 0.079

java.lang.IllegalArgumentException: Unable to find flow 'pause-duration-from-input'

java.lang.IllegalArgumentException: Unable to find flow 'pause-duration-from-input'
	at io.kestra.core.runners.TestRunnerUtils.lambda$runOneUntilPaused$1(TestRunnerUtils.java:121)
	at java.base/java.util.Optional.orElseThrow(Optional.java:403)
	at io.kestra.core.runners.TestRunnerUtils.runOneUntilPaused(TestRunnerUtils.java:121)
	at io.kestra.plugin.core.flow.PauseTest$Suite.runDurationFromInput(PauseTest.java:201)
	at io.kestra.plugin.core.flow.PauseTest.delayFromInput(PauseTest.java:66)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at io.micronaut.test.extensions.junit5.MicronautJunit5Extension$2.proceed(MicronautJunit5Extension.java:142)
	at io.micronaut.test.extensions.AbstractMicronautExtension.interceptEach(AbstractMicronautExtension.java:162)
	at io.micronaut.test.extensions.AbstractMicronautExtension.interceptTest(AbstractMicronautExtension.java:119)
	at io.micronaut.test.extensions.junit5.MicronautJunit5Extension.interceptTestMethod(MicronautJunit5Extension.java:129)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

core > io.kestra.plugin.core.flow.PauseTest > parallelDelay() failed ❌ in 0.044

java.lang.IllegalArgumentException: Unable to find flow 'each-parallel-pause'

java.lang.IllegalArgumentException: Unable to find flow 'each-parallel-pause'
	at io.kestra.core.runners.TestRunnerUtils.lambda$runOne$0(TestRunnerUtils.java:79)
	at java.base/java.util.Optional.orElseThrow(Optional.java:403)
	at io.kestra.core.runners.TestRunnerUtils.runOne(TestRunnerUtils.java:79)
	at io.kestra.core.runners.TestRunnerUtils.runOne(TestRunnerUtils.java:66)
	at io.kestra.plugin.core.flow.PauseTest$Suite.runParallelDelay(PauseTest.java:219)
	at io.kestra.plugin.core.flow.PauseTest.parallelDelay(PauseTest.java:72)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at io.micronaut.test.extensions.junit5.MicronautJunit5Extension$2.proceed(MicronautJunit5Extension.java:142)
	at io.micronaut.test.extensions.AbstractMicronautExtension.interceptEach(AbstractMicronautExtension.java:162)
	at io.micronaut.test.extensions.AbstractMicronautExtension.interceptTest(AbstractMicronautExtension.java:119)
	at io.micronaut.test.extensions.junit5.MicronautJunit5Extension.interceptTestMethod(MicronautJunit5Extension.java:129)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.tryRemoveAndExec(ForkJoinPool.java:1351)
	at java.base/java.util.concurrent.ForkJoinTask.awaitDone(ForkJoinTask.java:422)
	at java.base/java.util.concurrent.ForkJoinTask.join(ForkJoinTask.java:651)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

core > io.kestra.plugin.core.flow.PauseTest > delay() failed ❌ in 0.053

java.lang.IllegalArgumentException: Unable to find flow 'pause-delay'

java.lang.IllegalArgumentException: Unable to find flow 'pause-delay'
	at io.kestra.core.runners.TestRunnerUtils.lambda$runOneUntilPaused$1(TestRunnerUtils.java:121)
	at java.base/java.util.Optional.orElseThrow(Optional.java:403)
	at io.kestra.core.runners.TestRunnerUtils.runOneUntilPaused(TestRunnerUtils.java:121)
	at io.kestra.plugin.core.flow.PauseTest$Suite.runDelay(PauseTest.java:183)
	at io.kestra.plugin.core.flow.PauseTest.delay(PauseTest.java:60)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at io.micronaut.test.extensions.junit5.MicronautJunit5Extension$2.proceed(MicronautJunit5Extension.java:142)
	at io.micronaut.test.extensions.AbstractMicronautExtension.interceptEach(AbstractMicronautExtension.java:162)
	at io.micronaut.test.extensions.AbstractMicronautExtension.interceptTest(AbstractMicronautExtension.java:119)
	at io.micronaut.test.extensions.junit5.MicronautJunit5Extension.interceptTestMethod(MicronautJunit5Extension.java:129)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)