feat(stepfunctions): close conformance gap with 23 missing ops

[vieiralucas]

Summary

• 23 new Step Functions handlers covering activities + task tokens, state machine versions/aliases, map runs, RedriveExecution, StartSyncExecution, TestState, and ValidateStateMachineDefinition.
• New per-account state for activities, versions, aliases, map runs, and pending task tokens.
• States conformance: 14/37 -> 37/37 (100%).

Test plan

• cargo test -p fakecloud-conformance --test stepfunctions -> 23 pass
• cargo run -p fakecloud-conformance -- run --services states -> 37/37 OK
• cargo run -p fakecloud-conformance -- audit / check -> PASS
• cargo clippy --workspace --all-targets -- -D warnings
• cargo fmt

---

Summary by cubic

Implements 23 missing AWS Step Functions operations and closes the states emulator conformance gap. Conformance is now 37/37 (100%) with per-account state for activities, versions/aliases, map runs, and task tokens.

• New Features

  • Activities: create/describe/list/delete + GetActivityTask; persists task tokens per account.
  • Versions & Aliases: publish/list/delete versions; CRUD aliases with weighted routing.
  • Map Runs: describe/list/update; per-account storage; 404 on unknown ARNs.
  • Execution: RedriveExecution; StartSyncExecution (EXPRESS); TestState; ValidateStateMachineDefinition.

• Bug Fixes

  • ListStateMachineAliases anchors on ':' to prevent prefix bleed.
  • routingConfiguration validated (1–2 routes; weights 0–100 sum to 100; version ARN required).
  • StartSyncExecution validates JSON input and returns InvalidExecutionInput on bad payloads.

^{Written for commit 3eb1e56. Summary will update on new commits.}

[codecov]

Codecov Report

❌ Patch coverage is 4.24779% with 541 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
crates/fakecloud-stepfunctions/src/service.rs	2.52%	541 Missing ⚠️

📢 Thoughts on this report? Let us know!

[cubic-dev-ai]

4 issues found across 4 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:1037">
P2: `CreateStateMachineAlias` accepts invalid `routingConfiguration` values instead of validating required route count/weights.</violation>

<violation number="2" location="crates/fakecloud-stepfunctions/src/service.rs:1116">
P2: `ListStateMachineAliases` uses an over-broad prefix match and can return aliases for the wrong state machine.</violation>

<violation number="3" location="crates/fakecloud-stepfunctions/src/service.rs:1142">
P2: `UpdateStateMachineAlias` does not validate `routingConfiguration` and can store invalid routing weights.</violation>

<violation number="4" location="crates/fakecloud-stepfunctions/src/service.rs:1255">
P2: `StartSyncExecution` should validate `input` as JSON and return `InvalidExecutionInput` for malformed payloads.</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 1 file (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-stepfunctions/src/service.rs">

<violation number="1" location="crates/fakecloud-stepfunctions/src/service.rs:1469">
P2: `routingConfiguration` validation is incomplete: it accepts routes from different state machines. Reject mixed parent ARNs so alias routing stays valid and AWS-compatible.</violation>
</file>

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

[cubic-dev-ai]

P2: routingConfiguration validation is incomplete: it accepts routes from different state machines. Reject mixed parent ARNs so alias routing stays valid and AWS-compatible.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At crates/fakecloud-stepfunctions/src/service.rs, line 1469:

<comment>`routingConfiguration` validation is incomplete: it accepts routes from different state machines. Reject mixed parent ARNs so alias routing stays valid and AWS-compatible.</comment>

<file context>
@@ -1425,6 +1414,61 @@ fn resource_not_found(arn: &str) -> AwsServiceError {
+            format!("routingConfiguration weights must sum to 100, got {total}."),
+        ));
+    }
+    Ok(parsed)
+}
+
</file context>

Suggested change

	Ok(parsed)
	let parent = parsed[0]
	.state_machine_version_arn
	.rsplit_once(':')
	.map(|(p, _)| p)
	.ok_or_else(|| {
	AwsServiceError::aws_error(
	StatusCode::BAD_REQUEST,
	"ValidationException",
	"stateMachineVersionArn must be a version ARN.",
	)
	})?;
	if parsed.iter().any(|r| {
	r.state_machine_version_arn
	.rsplit_once(':')
	.map(|(p, _)| p)
	!= Some(parent)
	}) {
	return Err(AwsServiceError::aws_error(
	StatusCode::BAD_REQUEST,
	"ValidationException",
	"All routingConfiguration stateMachineVersionArn values must belong to the same state machine.",
	));
	}
	Ok(parsed)