feat(lambda): close conformance gap with 72 missing ops

[vieiralucas]

Summary

• 72 new Lambda handlers in extras.rs covering aliases, layers, function URL configs, concurrency (reserved + provisioned), code signing, event invoke configs, runtime management, scaling, recursion, capacity providers, durable executions + callbacks, and lifecycle extras (GetFunctionConfiguration, UpdateFunction{Code,Configuration}, GetAccountSettings, InvokeAsync, InvokeWithResponseStream).
• Resolver rewritten to recognise the many date prefixes the SDK uses per op family.
• Big new state surface: aliases, layers, function URL configs, concurrency, provisioned concurrency, code signing configs + function bindings, event invoke configs, runtime/scaling/recursion configs, tags, capacity providers, durable executions, account settings.
• Lambda conformance: 13/85 -> 85/85 (100%); workspace baseline +2615 passing variants.

Test plan

• cargo test -p fakecloud-conformance --test lambda -> 24 pass
• cargo run -p fakecloud-conformance -- run --services lambda -> 85/85 OK
• cargo run -p fakecloud-conformance -- audit / check -> PASS
• cargo clippy --workspace --all-targets -- -D warnings
• cargo fmt

---

Summary by cubic

Adds 72 missing Lambda operations to fakecloud-lambda to reach 100% conformance (85/85). State now persists all new resources and configs.

• New Features

  • Handlers for aliases/versions/layers; function URLs; reserved and provisioned concurrency; code signing + function bindings; event invoke configs; runtime/scaling/recursion; tags; capacity providers; durable executions + callbacks; and lifecycle extras (Get/UpdateFunction*, GetAccountSettings, InvokeAsync/InvokeWithResponseStream).
  • Includes per-resource policies/permissions and per-qualifier configs.

• Refactors

  • Router matches by path shape across mixed Lambda API date prefixes; removed date-specific branches.
  • Added extras.rs; exposed LambdaService state; durable executions now persist FunctionArn for correct list-by-function filtering.
  • Tests: tightened InvokeWithResponseStream failure handling; added 5 unit tests.
  • Conformance baseline updated (variants passed now 58,040; Lambda 3,347/3,347).

^{Written for commit d231c84. Summary will update on new commits.}

[cubic-dev-ai]

4 issues found across 6 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-lambda/src/service.rs">

<violation number="1" location="crates/fakecloud-lambda/src/service.rs:449">
P2: This `if false { ... }` block is dead code that can never execute. If it's kept as documentation, convert it to a comment; otherwise remove it entirely. Dead code behind `if false` confuses readers about whether routes are actually handled.</violation>

<violation number="2" location="crates/fakecloud-lambda/src/service.rs:471">
P2: Several date-specific routing blocks (prefixes `2019-09-25`, `2024-08-31`, `2025-11-30`/`2025-04-01`, `2024-09-01`/`2025-12-01`, `2020-04-22`) are unreachable dead code — the "any prefix" handlers above already return early for the same path patterns. These ~150 lines of dead routing add maintenance burden and make the router harder to reason about. Consider removing them.</violation>
</file>

<file name="crates/fakecloud-lambda/src/extras.rs">

<violation number="1" location="crates/fakecloud-lambda/src/extras.rs:1511">
P1: Checkpointed durable executions are created without a function ARN, so list-by-function filtering can miss them.</violation>
</file>

<file name="crates/fakecloud-conformance/tests/lambda.rs">

<violation number="1" location="crates/fakecloud-conformance/tests/lambda.rs:379">
P2: Don't discard the `invoke_with_response_stream` result; this test currently passes even when the route fails.</violation>
</file>

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

[codecov]

Codecov Report

❌ Patch coverage is 33.18182% with 1323 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
crates/fakecloud-lambda/src/extras.rs	34.52%	1047 Missing ⚠️
crates/fakecloud-lambda/src/service.rs	20.91%	276 Missing ⚠️

📢 Thoughts on this report? Let us know!

[cubic-dev-ai]

1 issue found across 3 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-lambda/src/extras.rs">

<violation number="1" location="crates/fakecloud-lambda/src/extras.rs:1517">
P2: Avoid hardcoding `us-east-1` when deriving the function ARN; use the account’s configured region so durable execution metadata is correct in other regions.</violation>
</file>

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

[cubic-dev-ai]

P2: Avoid hardcoding us-east-1 when deriving the function ARN; use the account’s configured region so durable execution metadata is correct in other regions.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At crates/fakecloud-lambda/src/extras.rs, line 1517:

<comment>Avoid hardcoding `us-east-1` when deriving the function ARN; use the account’s configured region so durable execution metadata is correct in other regions.</comment>

<file context>
@@ -1501,20 +1501,39 @@ impl LambdaService {
+        let derived_arn = body_arn.unwrap_or_else(|| match body_function {
+            Some(name) if name.starts_with("arn:") => name,
+            Some(name) => format!(
+                "arn:aws:lambda:us-east-1:{}:function:{name}",
+                req.account_id
+            ),
</file context>

Suggested change

	"arn:aws:lambda:us-east-1:{}:function:{name}",
	req.account_id
	),
	"arn:aws:lambda:{}:{}:function:{name}",
	state.region, req.account_id