feat(eventbridge): implement real EventBridge → Step Functions delivery

[vieiralucas]

Summary

• EventBridge rules and Scheduler schedules targeting Step Functions now actually start executions
• Added StepFunctionsDelivery trait to the core delivery bus
• Wired up delivery in both EventBridge service and Scheduler code paths
• State machine executions are started with the event payload as input, using the same ASL interpreter

Test plan

• E2E test: EventBridge rule starts and completes Step Functions execution
• Existing eb_put_events_stub_targets_no_error still passes
• cargo clippy -D warnings clean
• CI green

---

Summary by cubic

EventBridge rules and Scheduler schedules targeting Step Functions now start real executions with the event payload as input. This replaces stubs, runs via the ASL interpreter, and supports SNS, EventBridge, SQS, and Lambda tasks inside those executions.

• New Features

  • New StepFunctionsDelivery in fakecloud-core and StepFunctionsDeliveryImpl in fakecloud-server.
  • EventBridge and Scheduler now call the delivery bus to start executions.
  • start_execution_from_delivery in fakecloud-stepfunctions, with a full interpreter delivery bus (SNS, EventBridge, SQS, Lambda) for EB/Scheduler-started runs.
  • E2E test covers EB rule starting and completing an execution; state recording remains for introspection.

• Bug Fixes

  • Validate input JSON before starting cross-service executions; reject malformed payloads.
  • Include Lambda in the SNS fanout bus for SFN-triggered runs so SNS→Lambda subscriptions fire during EB-started executions.

^{Written for commit 88ea29f. Summary will update on new commits.}

[cubic-dev-ai]

2 issues found across 7 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="crates/fakecloud-stepfunctions/src/service.rs">

<violation number="1" location="crates/fakecloud-stepfunctions/src/service.rs:896">
P2: Validate cross-service execution input as JSON before starting execution. Without validation, malformed payloads are silently executed as `{}` via interpreter fallback.</violation>
</file>

<file name="crates/fakecloud-server/src/main.rs">

<violation number="1" location="crates/fakecloud-server/src/main.rs:229">
P1: EventBridge/Scheduler-started Step Functions executions are wired with a reduced delivery bus, so SNS/EventBridge Task integrations silently no-op instead of delivering.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

1 issue found across 2 files (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="crates/fakecloud-server/src/main.rs">

<violation number="1" location="crates/fakecloud-server/src/main.rs:231">
P2: SFN-triggered SNS publishes are configured with an SQS-only bus, so SNS Lambda subscriptions are never invoked.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}