[Fix #1489] Serializing java defined files

[fjtirado]

Fix #1489

[Copilot]

Pull request overview

Fixes #1489 by improving serialization/deserialization of workflows built via the Java DSL (including Java lambdas/method references), so generated YAML/JSON remains well-formed and more editor-friendly.

Changes:

• Introduces an experimental Jackson module to serialize function-like metadata (including SerializedLambda capture data) and to deserialize it back when possible.
• Refactors Java DSL “function call” plumbing to store callable objects in CallFunction.with arguments and task metadata rather than embedding custom task subtypes.
• Updates executors/builders and tests to validate workflow round-tripping (write → read) and predicate/function handling.

Reviewed changes

Copilot reviewed 111 out of 111 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
serialization/src/main/java/io/serverlessworkflow/serialization/DeserializeHelper.java	Adds overload to reuse a pre-parsed tree node during oneOf deserialization.
impl/json-utils/src/main/java/io/serverlessworkflow/impl/jackson/ObjectMapperFactoryProvider.java	Disables Jackson FAIL_ON_EMPTY_BEANS to allow serializing function/lambda placeholders.
impl/core/src/main/java/io/serverlessworkflow/impl/executors/SwitchExecutor.java	Switch filter building now operates on SwitchItem (supports metadata-based predicates).
impl/core/src/main/java/io/serverlessworkflow/impl/executors/ListenExecutor.java	Null-guards until when building the until predicate.
impl/core/src/main/java/io/serverlessworkflow/impl/executors/ForExecutor.java	Defers building collection/while resolvers to build time (builder methods).
impl/core/src/main/java/io/serverlessworkflow/impl/events/EventRegistrationBuilderInfo.java	Simplifies until/until-consumed registration logic.
generators/jackson/src/main/java/io/serverlessworkflow/generator/jackson/JacksonMixInPojo.java	Makes generated MixIns public (accessibility for Jackson).
fluent/spec/src/test/java/io/serverlessworkflow/fluent/spec/WorkflowBuilderTest.java	Updates default namespace expectation to org-acme.
fluent/spec/src/main/java/io/serverlessworkflow/fluent/spec/BaseWorkflowBuilder.java	Changes DEFAULT_NAMESPACE to org-acme.
experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/TypesUtils.java	Introduces utils for task metadata initialization and shared constants.
experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/TaskPredicate.java	New helper to attach/retrieve predicates via TaskMetadata additional properties.
experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java	Moves/refactors lambda reflection utilities (SerializedLambda extraction + class loading).
experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ForTaskFunction.java	New helper for storing for-loop predicates/collections via metadata (instead of subtype).
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/UntilPredicate.java	Removes subtype-based until predicate container.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/UniqueIdBiFunction.java	Moves package + uses FunctionObject marker for serializability.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedPredicate.java	Marks typed predicate as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedFunction.java	Marks typed function as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedFilterPredicate.java	Marks typed filter predicate as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedFilterFunction.java	Marks typed filter function as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedContextPredicate.java	Marks typed context predicate as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedContextFunction.java	Marks typed context function as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/SwitchCasePredicate.java	Removes subtype-based switch-case predicate container.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/SerializablePredicate.java	Moves package + uses FunctionObject marker for serializability.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/SerializableFunction.java	Moves package + uses FunctionObject marker for serializability.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/SerializableConsumer.java	Moves package + uses FunctionObject marker for serializability.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/OutputAsFunction.java	Removes subtype-based output mapping container.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/MapSetTaskConfiguration.java	Replaces subclass with factory method creating SetTaskConfiguration.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopPredicateIndexFilter.java	Marks loop predicate interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopPredicateIndexContext.java	Marks loop predicate interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopPredicateIndex.java	Marks loop predicate interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopPredicate.java	Marks loop predicate interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopFunctionIndex.java	Marks loop function interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopFunction.java	Marks loop function interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/InstanceIdFunction.java	Moves package + uses FunctionObject marker for serializability.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/InputFromFunction.java	Removes subtype-based input mapping container.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/FunctionObject.java	Introduces marker interface (Serializable) for runtime-invoked functional types.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ForTaskFunction.java	Removes subtype-based for-task container.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/FilterPredicate.java	Marks filter predicate interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/FilterFunction.java	Marks filter function interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ExportAsFunction.java	Removes subtype-based export mapping container.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ContextPredicate.java	Marks context predicate interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ContextFunction.java	Marks context function interface as FunctionObject.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/CallJava.java	Refactors to produce CallFunction + typed with arguments rather than custom task subtypes.
experimental/test/src/test/resources/logback.xml	Adds test logback configuration for debug visibility.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/TestSerializationUtils.java	Adds helper to write/read workflows in-memory (YAML) for round-trip tests.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/FuncTryCatchTest.java	Wraps workflow creation in serialization round-trip.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/FuncHttpTest.java	Wraps workflow creation in serialization round-trip.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/FuncEventFilterTest.java	Ensures listen workflows round-trip before execution.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/FuncDSLSerializationTest.java	New parameterized test validating YAML/JSON round-trip equality and execution.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/FuncDoTaskTest.java	Runs workflow after serialization round-trip.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/FuncCallAsyncTest.java	Runs workflow after serialization round-trip.
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/ForkFuncTest.java	Adjusts test to verify captured state survives serialization (captured field).
experimental/test/src/test/java/io/serverlessworkflow/fluent/test/ForEachFuncTest.java	Uses serializable functions and round-trip utility.
experimental/test/pom.xml	Adds test deps for API, logback, params, and new fluent serialization module.
experimental/pom.xml	Adds new experimental fluent jackson serialization module to dependencyManagement.
experimental/lambda/src/test/java/io/serverless/workflow/impl/executors/func/ModelTest.java	Updates tests to use plain OutputAs / CallTask and function objects.
experimental/lambda/src/test/java/io/serverless/workflow/impl/executors/func/ForTaskFunctionRegressionTest.java	Updates regression test to new metadata-based ForTaskFunction utility approach.
experimental/lambda/src/test/java/io/serverless/workflow/impl/executors/func/CallTest.java	Updates call/switch/for tests to new CallFunction + TaskPredicate approach.
experimental/lambda/src/test/java/io/serverless/workflow/impl/executors/func/CallJavaContextFunctionTest.java	Updates to new CallTask().withCallFunction(...) style.
experimental/lambda/src/main/resources/META-INF/services/io.serverlessworkflow.impl.executors.CallableTaskBuilder	Switches SPI registration to unified JavaCallFunctionBuilder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaSwitchExecutorBuilder.java	Reads predicates from task metadata rather than SwitchCase subtype.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaLoopFunctionIndexCallExecutorBuilder.java	Removes old subtype-based builder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaLoopFunctionIndexCallExecutor.java	Adds input/output class optionals to executor constructor.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaLoopFunctionCallExecutorBuilder.java	Removes old subtype-based builder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaLoopFunctionCallExecutor.java	Adds input/output class optionals to executor constructor.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaListenExecutorBuilder.java	Reads until predicate from metadata rather than Until subtype.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaFuncUtils.java	Simplifies predicate building to accept raw predicate object.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaFunctionCallExecutorBuilder.java	Removes old subtype-based builder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaForExecutorBuilder.java	Uses metadata-based ForTaskFunction and supports multiple predicate interface shapes.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaFilterFunctionCallExecutorBuilder.java	Removes old subtype-based builder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaContextFunctionCallExecutorBuilder.java	Removes old subtype-based builder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaConsumerCallExecutorBuilder.java	Removes old subtype-based builder.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaCallFunctionBuilder.java	New unified builder to execute Java calls encoded as CallFunction(call=Java).
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/AbstractJavaCallExecutor.java	Removes unused no-arg constructor; relies on optionals for typing.
experimental/fluent/pom.xml	Adds new jackson module under experimental fluent.
experimental/fluent/jackson/src/main/resources/META-INF/services/com.fasterxml.jackson.databind.Module	Registers FuncJacksonModule via service loader.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/TaskMetadataSerializer.java	Serializes TaskMetadata.additionalProperties with type wrappers.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/TaskMetadataDeserializer.java	Deserializes TaskMetadata.additionalProperties with type wrappers.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/SerializedLambdaWriter.java	Writes captured args for SerializedLambda during serialization.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/SerializedLambdaDeserializer.java	Rehydrates SerializedLambda from JSON, including captured args.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/SerializationUtils.java	Implements typed wrapper encoding/decoding for metadata values.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/SerializableFunctionSerializer.java	Serializes serializable lambdas via SerializedLambda, otherwise string fallback.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/OutputAsMixInEx.java	Overrides OutputAs handling with custom serializer/deserializer for function objects.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/FunctionDeserializer.java	Deserializes Function from SerializedLambda.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/FunctionArgumentsSerializer.java	Serializes FunctionArguments.additionalProperties with typed wrapper encoding.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/FunctionArgumentsDeserializer.java	Deserializes FunctionArguments.additionalProperties with typed wrapper decoding.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/FuncOutputAsSerializer.java	Serializes OutputAs.object with type wrapper when it’s a FunctionObject.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/FuncOutputAsDeserializer.java	Deserializes OutputAs from typed wrapper or falls back to oneOf handling.
experimental/fluent/jackson/src/main/java/io/serverlessworkflow/fluent/func/serialization/jackson/FuncJacksonModule.java	Registers all serializers/deserializers/mixins for function/metadata/lambda serialization.
experimental/fluent/jackson/pom.xml	New module definition and dependencies for fluent Jackson serialization.
experimental/fluent/func/src/test/java/io/serverlessworkflow/fluent/func/FuncDSLUniqueIdTest.java	Updates tests to validate unique-id behavior with CallFunction shape.
experimental/fluent/func/src/test/java/io/serverlessworkflow/fluent/func/FuncDSLTest.java	Updates tests to use CallFunction instead of old CallJava task subtypes.
experimental/fluent/func/src/test/java/io/serverlessworkflow/fluent/func/FuncDSLTaskNameTest.java	Removes subtype assertions for switch case predicates.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/spi/FuncTransformations.java	Replaces subtype wrappers with InputFrom/OutputAs object storage and typed wrappers.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/spi/FuncTaskTransformations.java	Replaces export wrappers with ExportAs object storage and typed wrappers.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncTaskItemListBuilder.java	Adds set(name, Map) convenience overload.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncSwitchTaskBuilder.java	Stores switch predicates in metadata via TaskPredicate instead of SwitchCase subtype.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncSetTaskBuilder.java	Uses MapSetTaskConfiguration.map(...) factory.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncListenToBuilder.java	Stores until predicates in metadata via TaskPredicate.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncListenTaskBuilder.java	Stores until predicates in metadata; passes listen task into strategy builder.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncForTaskBuilder.java	Migrates to plain ForTask + metadata helpers; adds serializable call-task helpers.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncForkTaskBuilder.java	Uses CallTask().withCallFunction(...) instead of old wrapper.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncEmitEventPropertiesBuilder.java	Updates imports to new SerializableFunction package.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncCallTaskBuilder.java	Uses CallTask + CallFunction; enforces serializable function overloads.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/Step.java	Updates imports to new reflection/serializable function packages.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/FuncEventFilterSpec.java	Updates imports to new SerializablePredicate package.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/FuncEmitSpec.java	Updates imports to new reflection/serializable function packages.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/FuncDSL.java	Updates imports; tightens for-each function types to serializable functions.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/CommonFuncOps.java	Updates imports to new reflection/serializable function packages.
api/src/main/java/io/serverlessworkflow/api/WorkflowWriter.java	Adds trace logging of serialized workflow output.
api/src/main/java/io/serverlessworkflow/api/ObjectMapperFactory.java	Disables Jackson FAIL_ON_EMPTY_BEANS for API mappers.

Comments suppressed due to low confidence (2)

experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:102

• Public API method name serializedFromFuntion contains a typo. Since this is used across modules, consider keeping it as a deprecated alias and introducing the correctly spelled serializedFromFunction to avoid cementing the typo in the API.
  experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:110
• Thread.currentThread().getContextClassLoader() can be null in some runtimes, which would cause a NullPointerException here during deserialization. Consider falling back to ReflectionUtils.class.getClassLoader() when the context class loader is null.

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[Copilot]

Pull request overview

Copilot reviewed 121 out of 121 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:95

• serializedFromFuntion is a public API with a typo in the method name. Since this is used outside this class, a safe approach is to keep the misspelled method as a deprecated wrapper and introduce a correctly spelled serializedFromFunction method for new call sites.
  experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:129
• inferMethodType(SerializedLambda) uses sl.getClass().getClassLoader() (i.e., the class loader of SerializedLambda, typically the bootstrap loader). This can fail to resolve user-defined parameter/return types referenced in the method descriptor, breaking type inference for lambdas that mention project classes. Use the thread context class loader (or another application class loader) instead.

[Copilot]

Pull request overview

Copilot reviewed 121 out of 121 changed files in this pull request and generated 5 comments.

Comments suppressed due to low confidence (2)

experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:129

• inferMethodType(SerializedLambda) uses sl.getClass().getClassLoader() (bootstrap loader) to resolve method descriptor types. This can fail when the lambda signature references application classes, because the bootstrap classloader can't load them. Prefer using the TCCL (or the capturing class’ loader) to resolve the descriptor.
  experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:99
• Public API method name serializedFromFuntion contains a typo. To avoid cementing the misspelling, add a correctly spelled alias (and deprecate the misspelled one) while keeping backward compatibility.

[Copilot]

Pull request overview

Copilot reviewed 121 out of 121 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:130

• inferMethodType(SerializedLambda sl) passes sl.getClass().getClassLoader() into MethodType.fromMethodDescriptorString(...). Since SerializedLambda is in java.base, this is typically the bootstrap loader (often null), which can fail to resolve application types referenced in the method descriptor and break type inference at runtime.
  experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/ReflectionUtils.java:101
• Public API method name serializedFromFuntion has a typo ("Funtion"). This is easy to accidentally propagate into more call sites and hard to fix later without breaking compatibility.

[Copilot]

Pull request overview

Copilot reviewed 122 out of 122 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 122 out of 122 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 122 out of 122 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

experimental/types/src/main/java/io/serverlessworkflow/api/types/utils/TaskMetadataKeys.java:18

• TaskMetadataKeys is an empty utility class with an implicit public constructor. This makes it instantiable and looks accidental; it can also trip style checks for utility classes. Either remove it if unused, or at least make the constructor private.

[ricardozanini]

I have a few nitpicks, but we can fix them along the way. Looks great!

[Copilot]

Pull request overview

Copilot reviewed 122 out of 122 changed files in this pull request and generated 1 comment.