Add defaultEventSource to WorkflowApplication

[matheusandre1]

Many thanks for submitting your Pull Request ❤️!

What this PR does / why we need it: Closes: #1554

Special notes for reviewers:

Additional information (if needed):

[ricardozanini]

@matheusandre1 you must sign your commits with -S.

[matheusandre1]

@matheusandre1 you must sign your commits with -S.

Sorry, I always forget about that.

[fjtirado]

@matheusandre1
Lets make default event source a WorkflowValueResolver, so it returns an URI from the WorkflowContext, TaskContext and Model

[Copilot]

Pull request overview

This PR improves CloudEvent emission defaults by introducing an application-level default source resolver and by ensuring emitted events always have a time value, aligning emitted events more closely with the Serverless Workflow spec requirements discussed in #1554.

Changes:

• Added defaultEventSource to WorkflowApplication (configurable via builder, with a sensible default resolver).
• Updated EmitExecutor to default source via the application’s resolver and to always set time (defaulting to OffsetDateTime.now()).
• Added test coverage (including a YAML-based workflow sample) verifying defaulting and precedence behavior for source, time, and id.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
impl/test/src/test/resources/workflows-samples/emit-default-source.yaml	Adds a YAML workflow sample used to verify default CloudEvent source behavior when loading workflows from YAML.
impl/test/src/test/java/io/serverlessworkflow/impl/test/EmitExecutorTest.java	Adds tests covering source defaulting/override precedence, and time/id defaults for emitted events.
impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowApplication.java	Introduces defaultEventSource on the application and builder APIs to configure it, with a default resolver.
impl/core/src/main/java/io/serverlessworkflow/impl/executors/EmitExecutor.java	Switches emitted event source defaulting to use WorkflowApplication.defaultEventSource() and defaults time to now.
impl/core/src/main/java/io/serverlessworkflow/impl/events/EmitSourceResolver.java	Adds the default resolver implementation that builds source from application id + workflow definition id.
impl/core/src/main/java/io/serverlessworkflow/impl/events/CloudEventUtils.java	Updates the static fallback source() URI value to a more meaningful identifier.

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

[ricardozanini]

@matheusandre1 when generating the source URI please add the prefix /. E.g. /org-acme/payment-processor/1.0.0

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowApplication.java:413

• withDefaultEventSource(URI) accepts null and wraps it into a resolver that returns null. That prevents the default EmitSourceResolver fallback from being applied and will later pass null into CloudEventBuilder.withSource(...) (likely causing a runtime NPE/IAE during emit). Fail fast by rejecting null here.

    public Builder withDefaultEventSource(URI defaultEventSource) {
      return withDefaultEventSource((workflow, task, model) -> defaultEventSource);
    }

impl/core/src/main/java/io/serverlessworkflow/impl/executors/EmitExecutor.java:109

• defaultEventSource().apply(...) is used directly as the CloudEvent source. If a custom resolver returns null (or a caller previously passed a null URI), this will propagate into ceBuilder.withSource(...) and fail at runtime with an opaque NPE. Enforce a non-null resolved source with a clear message.

                    workflow
                        .definition()
                        .application()
                        .defaultEventSource()
                        .apply(workflow, taskContext, taskContext.input())));

[ricardozanini]

@matheusandre1 wanna open the counterpart in quarkus-flow? quarkiverse/quarkus-flow#776 We can use the defaultSource from here.

[matheusandre1]

@matheusandre1 wanna open the counterpart in quarkus-flow? quarkiverse/quarkus-flow#776 We can use the defaultSource from here.

I would, actually, but there are two open pull requests mentioning the issue.

[matheusandre1]

The GitHub PR is down; I'll submit the pull request when the next SDK release comes out.
cc: @ricardozanini