[Fix #1209] Adding Context and Filter predicate

[fjtirado]

Fix #1209

Also, as suggested by @ricardozanini, Java prefix is removed from functions.

[Copilot]

Pull request overview

This PR addresses issue #1209 by expanding Java predicate/function support to optionally receive workflow and task context, enabling context-aware filtering and evaluation across the experimental Java runtime and fluent DSL.

Changes:

• Introduces new context-aware predicate/function types (ContextPredicate, FilterPredicate, ContextFunction, FilterFunction) plus typed wrappers.
• Updates switch/listen/for execution paths to build predicates/functions from the new container/wrapper types.
• Refactors the fluent DSL and tests to use the renamed/updated function interfaces and new switch predicate container type.

Reviewed changes

Copilot reviewed 41 out of 41 changed files in this pull request and generated 16 comments.

Show a summary per file

File	Description
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/UntilPredicate.java	Stores predicates as Object (typed wrappers) and implements PredicateContainer to support multiple predicate shapes.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedFilterPredicate.java	Adds typed wrapper for FilterPredicate argument conversion.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedFilterFunction.java	Adds typed wrapper for FilterFunction argument conversion.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedContextPredicate.java	Adds typed wrapper for ContextPredicate argument conversion.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/TypedContextFunction.java	Renames typed context function wrapper to match new ContextFunction interface.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/SwitchCasePredicate.java	New switch-case container supporting plain/typed/context/task-aware predicates.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/SwitchCaseFunction.java	Removes the old SwitchCaseFunction container implementation.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/PredicateContainer.java	Introduces a common interface for types that “carry” a predicate object.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/OutputAsFunction.java	Updates overloads to use FilterFunction / ContextFunction and new typed wrappers.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopPredicateIndexFilter.java	Adds loop predicate shape that receives workflow/task context.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/LoopPredicateIndexContext.java	Adds loop predicate shape that receives workflow context.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/InputFromFunction.java	Updates overloads to use FilterFunction / ContextFunction and new typed wrappers.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ForTaskFunction.java	Extends while predicate options to include index + workflow/task context forms.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/FilterPredicate.java	Introduces predicate that receives workflow + task context.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/FilterFunction.java	Renames JavaFilterFunction to FilterFunction (context+task-aware function).
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ExportAsFunction.java	Updates overloads to use FilterFunction / ContextFunction and new typed wrappers.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/EventDataPredicate.java	Adds context-aware predicate overloads for event data filtering.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ContextPredicate.java	Introduces predicate that receives workflow context.
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/ContextFunction.java	Renames JavaContextFunction to ContextFunction (workflow-context-aware function).
experimental/types/src/main/java/io/serverlessworkflow/api/types/func/CallJava.java	Updates call variants and nested types to use ContextFunction / FilterFunction.
experimental/lambda/src/test/java/io/serverless/workflow/impl/executors/func/CallTest.java	Updates switch predicate test to use SwitchCasePredicate.
experimental/lambda/src/test/java/io/serverless/workflow/impl/executors/func/CallJavaContextFunctionTest.java	Updates test to use ContextFunction.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/expressions/func/JavaExpressionFactory.java	Adds predicate building for new predicate types and typed wrappers; updates priority logic.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaSwitchExecutorBuilder.java	Switch executor now uses SwitchCasePredicate and JavaFuncUtils.from(...).
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaListenExecutorBuilder.java	Listen executor now uses UntilPredicate + JavaFuncUtils.from(...).
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaFuncUtils.java	Replaces old typed-predicate construction helper with predicate-container based predicate building.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaForExecutorBuilder.java	Passes workflow/task context into the new loop predicate signature.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaFilterFunctionCallExecutorBuilder.java	Updates builder to use FilterFunction.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaFilterFunctionCallExecutor.java	Updates executor to call FilterFunction.apply(...).
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaContextFunctionCallExecutorBuilder.java	Updates builder to use ContextFunction.
experimental/lambda/src/main/java/io/serverlessworkflow/impl/executors/func/JavaContextFunctionCallExecutor.java	Updates executor to call ContextFunction.apply(...).
experimental/fluent/func/src/test/java/io/serverlessworkflow/fluent/func/FuncDSLUniqueIdTest.java	Updates test extraction/casts to FilterFunction.
experimental/fluent/func/src/test/java/io/serverlessworkflow/fluent/func/FuncDSLTest.java	Updates DSL tests to use FilterFunction.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/spi/FuncTransformations.java	Updates DSL transformation interfaces to accept ContextFunction / FilterFunction.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/spi/FuncTaskTransformations.java	Updates task-specific transformation interfaces to accept ContextFunction / FilterFunction.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/Step.java	Updates DSL Step APIs + Javadoc references to renamed function interfaces.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/ReflectionUtils.java	Updates type inference helpers to accept ContextFunction / FilterFunction.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/FuncDSL.java	Updates DSL entrypoints and internal wrappers to use renamed function interfaces.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/dsl/FuncCallStep.java	Updates internal step representation to store ContextFunction / FilterFunction.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncSwitchTaskBuilder.java	Switch DSL builder now constructs SwitchCasePredicate.
experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncCallTaskBuilder.java	Call-task DSL builder now accepts ContextFunction / FilterFunction.

Comments suppressed due to low confidence (2)

experimental/types/src/main/java/io/serverlessworkflow/api/types/func/FilterFunction.java:25

• This change renames the public API type JavaFilterFunction to FilterFunction (and similarly for context variants) across modules. That’s a breaking change beyond the stated goal of adding optional context parameters; if intentional, it should be called out in the PR description/release notes and (if needed) provide migration guidance or deprecation shims.
  experimental/lambda/src/main/java/io/serverlessworkflow/impl/expressions/func/JavaExpressionFactory.java:136
• buildIfFilter(...) still only recognizes Predicate and TypedPredicate. With the new ContextPredicate / FilterPredicate (and typed variants), when/if predicates stored in metadata will be silently ignored. Extend this method to handle the new predicate types the same way buildPredicate(...) does.

  public Optional<WorkflowPredicate> buildIfFilter(TaskBase task) {
    TaskMetadata metadata = task.getMetadata();
    if (metadata != null) {
      Object obj = metadata.getAdditionalProperties().get(TaskMetadataKeys.IF_PREDICATE);
      if (obj instanceof Predicate pred) {
        return Optional.of(fromPredicate(pred));
      } else if (obj instanceof TypedPredicate pred) {
        return Optional.of(fromPredicate(pred));
      }

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.

[Copilot]

Pull request overview

Copilot reviewed 41 out of 41 changed files in this pull request and generated 6 comments.

Comments suppressed due to low confidence (1)

experimental/fluent/func/src/test/java/io/serverlessworkflow/fluent/func/FuncDSLTest.java:118

• Test comment and assertion message still reference JavaFilterFunction, but the API type is now FilterFunction. Updating these strings will avoid confusion when reading failures and keep tests aligned with the renamed API.

    // JavaFilterFunction<T,R> is (T, WorkflowContextData, TaskContextData) -> R
    FilterFunction<String, Map<String, Object>> jf =
        (val, wfCtx, taskCtx) -> Map.of("wrapped", val, "wfId", wfCtx.instanceData().id());

    Workflow wf =
        FuncWorkflowBuilder.workflow("step-emit-export")
            .tasks(emit("emitWrapped", spec).exportAs(jf)) // chaining on Step
            .build();

    List<TaskItem> items = wf.getDo();
    assertEquals(1, items.size());
    Task t = items.get(0).getTask();
    assertNotNull(t.getEmitTask(), "EmitTask expected");

    // Export is attached to Task
    Export ex = t.getEmitTask().getExport();
    assertNotNull(ex, "Export should be set via Step.exportAs(JavaFilterFunction)");
    assertNotNull(ex.getAs(), "'as' should be populated");

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.

[ricardozanini]

LGTM, but Co-Pilot is pointing out a few null checks that I think are worth adding.

[fjtirado]

LGTM, but Co-Pilot is pointing out a few null checks that I think are worth adding.

Yes, I handle them a bit differently from what copilot recommended, if class is null, lets use the non typed variant.

[Copilot]

Pull request overview

Copilot reviewed 41 out of 41 changed files in this pull request and generated 8 comments.

Comments suppressed due to low confidence (1)

experimental/fluent/func/src/main/java/io/serverlessworkflow/fluent/func/FuncSwitchTaskBuilder.java:67

• The Objects.requireNonNull failure message says "When is required", but this branch is validating that then is present for a default case. Update the message to reflect what is actually required (e.g., "Then is required") to avoid confusing users.

    if (switchCaseValue.predicate() == null) {
      Objects.requireNonNull(switchCaseValue.getThen(), "When is required");
      if (switchCaseValue.getThen().getFlowDirectiveEnum() != null) {

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

You can also share your feedback on Copilot code review. Take the survey.