Files
mxaccessgw/clients/rust/tests/client_behavior.rs
T
Joseph Doherty 61644e63fb Rust: take Session::read_bulk tag list by borrowed slice
Changes the public signature from `Vec<String>` (owned) to
`&[impl AsRef<str>]` so callers can re-issue the same call repeatedly
without cloning at the call site. The bench''s steady-state loop now
passes `&tags` instead of `tags.clone()`; the CLI subcommand passes the
parsed `&items`; the integration test passes `&["Area001.Pump001.Speed"]`
straight from a string literal slice.

Honest perf note: this is an ergonomics change, not a measurable speedup.
The method still has to materialise an owned `Vec<String>` internally
because prost''s generated `ReadBulkCommand` field requires it, so the
total heap traffic per call is unchanged. Across two 30-second, 5-way
concurrent bench runs at bulkSize=6:

  pre-fix  (.clone() at caller): 145.35 calls/sec, p99  62.31 ms
  post-fix run 1 (&tags):        165.98 calls/sec, p99  40.65 ms
  post-fix run 2 (&tags):        146.19 calls/sec, p99  60.04 ms

Run-to-run variance (145-166) dominates any signal from the fix. Solo
Rust release stayed at 261-267 calls/sec across both API shapes,
confirming the bench is gateway-bound under 5-way contention rather
than client-allocation-bound. The change is kept because the borrowed
slice is the idiomatic Rust API shape for "list of items the callee
does not need to take ownership of", and it cleans up the explicit
clone from the bench's inner loop.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-20 05:49:33 -04:00

725 lines
25 KiB
Rust

use std::pin::Pin;
use std::sync::{
atomic::{AtomicBool, Ordering},
Arc,
};
use std::task::{Context, Poll};
use std::time::Duration;
use futures_core::Stream;
use futures_util::StreamExt;
use mxgateway_client::generated::mxaccess_gateway::v1::mx_access_gateway_server::{
MxAccessGateway, MxAccessGatewayServer,
};
use mxgateway_client::generated::mxaccess_gateway::v1::mx_command;
use mxgateway_client::generated::mxaccess_gateway::v1::mx_command_reply;
use mxgateway_client::generated::mxaccess_gateway::v1::mx_value::Kind;
use mxgateway_client::generated::mxaccess_gateway::v1::{
AcknowledgeAlarmReply, AcknowledgeAlarmRequest, ActiveAlarmSnapshot, AddItemReply,
BulkReadReply, BulkReadResult, BulkSubscribeReply, BulkWriteReply, BulkWriteResult,
CloseSessionReply, CloseSessionRequest, MxCommandKind, MxCommandReply, MxDataType, MxEvent,
MxEventFamily, MxStatusCategory, MxStatusProxy, MxStatusSource, MxValue, OpenSessionReply,
OpenSessionRequest, ProtocolStatus, ProtocolStatusCode, QueryActiveAlarmsRequest, SessionState,
StreamEventsRequest, SubscribeResult, WriteBulkEntry,
};
use mxgateway_client::{
ApiKey, ClientOptions, CommandError, Error, GatewayClient, MxStatus, MxValue as ClientMxValue,
MxValueProjection,
};
use serde_json::Value;
use tokio::net::TcpListener;
use tokio::sync::{mpsc, Mutex};
use tokio_stream::wrappers::{ReceiverStream, TcpListenerStream};
use tonic::transport::Server;
use tonic::{Request, Response, Status};
#[tokio::test]
async fn fake_server_receives_bearer_metadata_and_raw_client_is_reachable() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let mut client = GatewayClient::connect(
ClientOptions::new(endpoint).with_api_key(ApiKey::new("mxgw_fixture_secret")),
)
.await
.unwrap();
let _raw = client.raw_client();
let session = client
.open_session(OpenSessionRequest {
client_session_name: "rust-test".to_owned(),
..OpenSessionRequest::default()
})
.await
.unwrap();
assert_eq!(session.id(), "session-fixture");
assert_eq!(
state.authorization.lock().await.as_deref(),
Some("Bearer mxgw_fixture_secret")
);
}
#[tokio::test]
async fn session_helpers_build_commands_and_preserve_command_errors() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let session = client.session("session-fixture");
let item_handle = session.add_item(12, "Plant.Area.Tag").await.unwrap();
assert_eq!(item_handle, 34);
let last_command = state.last_command_kind.lock().await;
assert_eq!(*last_command, Some(MxCommandKind::AddItem as i32));
drop(last_command);
let error = session
.write(12, 34, ClientMxValue::int32(123), 0)
.await
.unwrap_err();
let Error::Command(error) = error else {
panic!("write failure should preserve the raw command reply: {error:?}");
};
assert_eq!(
error.reply().protocol_status.as_ref().unwrap().code,
ProtocolStatusCode::MxaccessFailure as i32
);
assert_eq!(error.reply().hresult, Some(-2147220992));
assert_eq!(error.reply().statuses.len(), 2);
}
#[tokio::test]
async fn subscribe_bulk_builds_one_bulk_command_and_returns_results() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let session = client.session("session-fixture");
let results = session
.subscribe_bulk(12, vec!["Area001.Pump001.Speed".to_owned()])
.await
.unwrap();
assert_eq!(results[0].item_handle, 34);
let last_command = state.last_command_kind.lock().await;
assert_eq!(*last_command, Some(MxCommandKind::SubscribeBulk as i32));
}
#[tokio::test]
async fn write_bulk_builds_one_bulk_command_and_returns_per_entry_results() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let session = client.session("session-fixture");
let results = session
.write_bulk(
12,
vec![
WriteBulkEntry {
item_handle: 901,
value: Some(int_value(11)),
user_id: 5,
},
WriteBulkEntry {
item_handle: 902,
value: Some(int_value(22)),
user_id: 5,
},
],
)
.await
.unwrap();
assert_eq!(results.len(), 2);
assert!(results[0].was_successful);
assert!(!results[1].was_successful);
let last_command = state.last_command_kind.lock().await;
assert_eq!(*last_command, Some(MxCommandKind::WriteBulk as i32));
}
#[tokio::test]
async fn read_bulk_forwards_timeout_and_unpacks_cached_flag() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let session = client.session("session-fixture");
let results = session
.read_bulk(12, &["Area001.Pump001.Speed"], 750)
.await
.unwrap();
let entry = &results[0];
assert!(entry.was_cached);
assert_eq!(entry.value.as_ref().and_then(|v| v.kind.as_ref()), Some(&Kind::Int32Value(99)));
assert_eq!(*state.last_read_bulk_timeout_ms.lock().await, Some(750));
}
#[tokio::test]
async fn event_stream_preserves_order_and_drop_cancels_server_stream() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let mut stream = client
.stream_events(StreamEventsRequest {
session_id: "session-fixture".to_owned(),
after_worker_sequence: 0,
})
.await
.unwrap();
assert_eq!(stream.next().await.unwrap().unwrap().worker_sequence, 1);
assert_eq!(stream.next().await.unwrap().unwrap().worker_sequence, 2);
drop(stream);
for _ in 0..20 {
if state.stream_dropped.load(Ordering::SeqCst) {
return;
}
tokio::time::sleep(Duration::from_millis(25)).await;
}
assert!(state.stream_dropped.load(Ordering::SeqCst));
}
#[tokio::test]
async fn acknowledge_alarm_returns_reply_with_native_status() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let reply = client
.acknowledge_alarm(AcknowledgeAlarmRequest {
session_id: "session-fixture".to_owned(),
client_correlation_id: "corr-1".to_owned(),
alarm_full_reference: "Tank01.Level.HiHi".to_owned(),
comment: "investigating".to_owned(),
operator_user: "alice".to_owned(),
})
.await
.unwrap();
assert_eq!(
reply.protocol_status.as_ref().unwrap().code,
ProtocolStatusCode::Ok as i32
);
assert_eq!(reply.status.as_ref().unwrap().success, 1);
}
#[tokio::test]
async fn query_active_alarms_streams_snapshot_rows() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let mut stream = client
.query_active_alarms(QueryActiveAlarmsRequest {
session_id: "session-fixture".to_owned(),
..QueryActiveAlarmsRequest::default()
})
.await
.unwrap();
let first = stream.next().await.unwrap().unwrap();
assert_eq!(first.alarm_full_reference, "Tank01.Level.HiHi");
}
#[test]
fn value_conversion_fixtures_keep_typed_projection_and_raw_metadata() {
let fixture = behavior_fixture("values/value-conversion-cases.json");
let cases = fixture["cases"].as_array().unwrap();
let int64_case = case_by_id(cases, "int64.large");
let int64_value = ClientMxValue::from_proto(MxValue {
data_type: MxDataType::Integer as i32,
variant_type: "VT_I8".to_owned(),
kind: Some(Kind::Int64Value(
int64_case["value"]["int64Value"]
.as_str()
.unwrap()
.parse()
.unwrap(),
)),
..MxValue::default()
});
assert_eq!(
int64_value.projection(),
MxValueProjection::Int64(9_223_372_036_854_770_000)
);
let raw_case = case_by_id(cases, "raw-fallback.variant");
let raw_value = ClientMxValue::from_proto(MxValue {
data_type: MxDataType::Unknown as i32,
variant_type: "VT_RECORD".to_owned(),
raw_diagnostic: raw_case["value"]["rawDiagnostic"]
.as_str()
.unwrap()
.to_owned(),
raw_data_type: raw_case["value"]["rawDataType"].as_i64().unwrap() as i32,
kind: Some(Kind::RawValue(vec![1, 2, 3, 4, 5])),
..MxValue::default()
});
assert_eq!(
raw_value.projection(),
MxValueProjection::Raw(vec![1, 2, 3, 4, 5])
);
assert_eq!(raw_value.raw().raw_data_type, 32767);
assert!(raw_value.raw().raw_diagnostic.contains("No lossless"));
}
#[test]
fn status_conversion_fixtures_preserve_raw_fields() {
let fixture = behavior_fixture("statuses/status-conversion-cases.json");
let cases = fixture["cases"].as_array().unwrap();
let raw_case = case_by_id(cases, "raw-unknown-category");
let status = MxStatus::from_proto(MxStatusProxy {
success: raw_case["status"]["success"].as_i64().unwrap() as i32,
category: MxStatusCategory::Unknown as i32,
detected_by: MxStatusSource::Unknown as i32,
detail: raw_case["status"]["detail"].as_i64().unwrap() as i32,
raw_category: raw_case["status"]["rawCategory"].as_i64().unwrap() as i32,
raw_detected_by: raw_case["status"]["rawDetectedBy"].as_i64().unwrap() as i32,
diagnostic_text: raw_case["status"]["diagnosticText"]
.as_str()
.unwrap()
.to_owned(),
});
assert_eq!(status.success(), 0);
assert_eq!(status.category(), Some(MxStatusCategory::Unknown));
assert_eq!(status.raw_category(), 99);
assert_eq!(status.raw_detected_by(), 77);
assert!(status.diagnostic_text().contains("preserved"));
}
#[test]
fn authentication_and_authorization_statuses_are_distinct_and_redacted() {
let auth = Error::from(Status::unauthenticated(
"invalid API key mxgw_visible_secret",
));
let denied = Error::from(Status::permission_denied("missing scope mxaccess.write"));
assert!(matches!(auth, Error::Authentication { .. }));
assert!(matches!(denied, Error::Authorization { .. }));
assert!(!auth.to_string().contains("visible_secret"));
}
#[test]
fn command_error_display_keeps_raw_reply_accessible() {
let reply = mxaccess_failure_reply();
let error = CommandError::new(reply.clone());
assert_eq!(error.reply().hresult, Some(-2147220992));
assert!(error.to_string().contains("MxaccessFailure"));
}
#[tokio::test]
async fn add_item_bulk_rejects_input_above_the_thousand_item_cap() {
let state = Arc::new(FakeState::default());
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let session = client.session("session-fixture");
let oversized: Vec<String> = (0..1001).map(|index| format!("Tag{index}")).collect();
let error = session.add_item_bulk(12, oversized).await.unwrap_err();
assert!(
matches!(&error, Error::InvalidArgument { name, .. } if name.as_str() == "tag_addresses"),
"expected InvalidArgument for tag_addresses, got {error:?}"
);
}
#[tokio::test]
async fn event_stream_surfaces_a_mid_stream_status_fault() {
let state = Arc::new(FakeState::default());
state.emit_stream_fault.store(true, Ordering::SeqCst);
let endpoint = spawn_fake_gateway(state.clone()).await;
let client = GatewayClient::connect(ClientOptions::new(endpoint))
.await
.unwrap();
let mut stream = client
.stream_events(StreamEventsRequest {
session_id: "session-fixture".to_owned(),
after_worker_sequence: 0,
})
.await
.unwrap();
assert_eq!(stream.next().await.unwrap().unwrap().worker_sequence, 1);
assert_eq!(stream.next().await.unwrap().unwrap().worker_sequence, 2);
let fault = stream.next().await.unwrap().unwrap_err();
assert!(
matches!(fault, Error::Unavailable { .. }),
"expected Error::Unavailable, got {fault:?}"
);
}
#[tokio::test]
async fn connect_with_unreadable_ca_file_reports_invalid_endpoint() {
let options = ClientOptions::new("https://127.0.0.1:65000")
.with_plaintext(false)
.with_ca_file("definitely-not-a-real-ca-file.pem");
// GatewayClient is not Debug, so unwrap_err is unavailable here.
let error = match GatewayClient::connect(options).await {
Ok(_) => panic!("connect should fail when the CA file cannot be read"),
Err(error) => error,
};
assert!(
matches!(error, Error::InvalidEndpoint { .. }),
"expected Error::InvalidEndpoint, got {error:?}"
);
}
#[derive(Default)]
struct FakeState {
authorization: Mutex<Option<String>>,
last_command_kind: Mutex<Option<i32>>,
last_read_bulk_timeout_ms: Mutex<Option<u32>>,
stream_dropped: Arc<AtomicBool>,
emit_stream_fault: AtomicBool,
}
#[derive(Clone)]
struct FakeGateway {
state: Arc<FakeState>,
}
#[tonic::async_trait]
impl MxAccessGateway for FakeGateway {
async fn open_session(
&self,
request: Request<OpenSessionRequest>,
) -> Result<Response<OpenSessionReply>, Status> {
*self.state.authorization.lock().await = request
.metadata()
.get("authorization")
.and_then(|value| value.to_str().ok())
.map(str::to_owned);
Ok(Response::new(OpenSessionReply {
session_id: "session-fixture".to_owned(),
backend_name: "fake".to_owned(),
worker_process_id: 1234,
worker_protocol_version: 1,
gateway_protocol_version: 1,
protocol_status: Some(ok_status("opened")),
..OpenSessionReply::default()
}))
}
async fn close_session(
&self,
request: Request<CloseSessionRequest>,
) -> Result<Response<CloseSessionReply>, Status> {
Ok(Response::new(CloseSessionReply {
session_id: request.into_inner().session_id,
final_state: SessionState::Closed as i32,
protocol_status: Some(ok_status("closed")),
}))
}
async fn invoke(
&self,
request: Request<mxgateway_client::generated::mxaccess_gateway::v1::MxCommandRequest>,
) -> Result<Response<MxCommandReply>, Status> {
let request = request.into_inner();
let kind = request
.command
.as_ref()
.map(|command| command.kind)
.unwrap_or_default();
*self.state.last_command_kind.lock().await = Some(kind);
if kind == MxCommandKind::Write as i32 {
return Ok(Response::new(mxaccess_failure_reply()));
}
if kind == MxCommandKind::SubscribeBulk as i32 {
return Ok(Response::new(MxCommandReply {
session_id: request.session_id,
correlation_id: "fake-correlation".to_owned(),
kind,
protocol_status: Some(ok_status("command ok")),
payload: Some(mx_command_reply::Payload::SubscribeBulk(
BulkSubscribeReply {
results: vec![SubscribeResult {
server_handle: 12,
tag_address: "Area001.Pump001.Speed".to_owned(),
item_handle: 34,
was_successful: true,
error_message: String::new(),
}],
},
)),
..MxCommandReply::default()
}));
}
if kind == MxCommandKind::WriteBulk as i32 {
// Echo one success and one failure so the test can assert the per-entry
// shape and verify the call did not throw on per-entry failure.
return Ok(Response::new(MxCommandReply {
session_id: request.session_id,
correlation_id: "fake-correlation".to_owned(),
kind,
protocol_status: Some(ok_status("command ok")),
payload: Some(mx_command_reply::Payload::WriteBulk(BulkWriteReply {
results: vec![
BulkWriteResult {
server_handle: 12,
item_handle: 901,
was_successful: true,
hresult: None,
statuses: vec![],
error_message: String::new(),
},
BulkWriteResult {
server_handle: 12,
item_handle: 902,
was_successful: false,
hresult: None,
statuses: vec![],
error_message: "invalid handle".to_owned(),
},
],
})),
..MxCommandReply::default()
}));
}
if kind == MxCommandKind::ReadBulk as i32 {
let read_command = request.command.as_ref().and_then(|c| {
if let Some(mx_command::Payload::ReadBulk(ref r)) = c.payload {
Some(r.timeout_ms)
} else {
None
}
});
*self.state.last_read_bulk_timeout_ms.lock().await = read_command;
return Ok(Response::new(MxCommandReply {
session_id: request.session_id,
correlation_id: "fake-correlation".to_owned(),
kind,
protocol_status: Some(ok_status("command ok")),
payload: Some(mx_command_reply::Payload::ReadBulk(BulkReadReply {
results: vec![BulkReadResult {
server_handle: 12,
tag_address: "Area001.Pump001.Speed".to_owned(),
item_handle: 34,
was_successful: true,
was_cached: true,
value: Some(int_value(99)),
quality: 192,
source_timestamp: None,
statuses: vec![],
error_message: String::new(),
}],
})),
..MxCommandReply::default()
}));
}
Ok(Response::new(MxCommandReply {
session_id: request.session_id,
correlation_id: "fake-correlation".to_owned(),
kind,
protocol_status: Some(ok_status("command ok")),
payload: Some(mx_command_reply::Payload::AddItem(AddItemReply {
item_handle: 34,
})),
..MxCommandReply::default()
}))
}
type StreamEventsStream = DropAwareStream;
async fn stream_events(
&self,
_request: Request<StreamEventsRequest>,
) -> Result<Response<Self::StreamEventsStream>, Status> {
let (sender, receiver) = mpsc::channel(4);
sender.send(Ok(event(1))).await.unwrap();
sender.send(Ok(event(2))).await.unwrap();
if self.state.emit_stream_fault.load(Ordering::SeqCst) {
sender
.send(Err(Status::unavailable("worker dropped the session")))
.await
.unwrap();
}
Ok(Response::new(DropAwareStream {
inner: ReceiverStream::new(receiver),
dropped: self.state.stream_dropped.clone(),
}))
}
async fn acknowledge_alarm(
&self,
_request: Request<AcknowledgeAlarmRequest>,
) -> Result<Response<AcknowledgeAlarmReply>, Status> {
Ok(Response::new(AcknowledgeAlarmReply {
session_id: "session-fixture".to_owned(),
correlation_id: "corr-1".to_owned(),
protocol_status: Some(ok_status("ack ok")),
status: Some(MxStatusProxy {
success: 1,
category: MxStatusCategory::Ok as i32,
detected_by: MxStatusSource::RespondingLmx as i32,
..MxStatusProxy::default()
}),
..AcknowledgeAlarmReply::default()
}))
}
type QueryActiveAlarmsStream =
Pin<Box<dyn Stream<Item = Result<ActiveAlarmSnapshot, Status>> + Send + 'static>>;
async fn query_active_alarms(
&self,
_request: Request<QueryActiveAlarmsRequest>,
) -> Result<Response<Self::QueryActiveAlarmsStream>, Status> {
let (sender, receiver) = mpsc::channel(4);
sender
.send(Ok(ActiveAlarmSnapshot {
alarm_full_reference: "Tank01.Level.HiHi".to_owned(),
..ActiveAlarmSnapshot::default()
}))
.await
.unwrap();
let stream = ReceiverStream::new(receiver);
Ok(Response::new(Box::pin(stream)))
}
}
struct DropAwareStream {
inner: ReceiverStream<Result<MxEvent, Status>>,
dropped: Arc<AtomicBool>,
}
impl Stream for DropAwareStream {
type Item = Result<MxEvent, Status>;
fn poll_next(mut self: Pin<&mut Self>, context: &mut Context<'_>) -> Poll<Option<Self::Item>> {
Pin::new(&mut self.inner).poll_next(context)
}
}
impl Drop for DropAwareStream {
fn drop(&mut self) {
self.dropped.store(true, Ordering::SeqCst);
}
}
async fn spawn_fake_gateway(state: Arc<FakeState>) -> String {
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
let address = listener.local_addr().unwrap();
let incoming = TcpListenerStream::new(listener);
let service = MxAccessGatewayServer::new(FakeGateway { state });
tokio::spawn(async move {
Server::builder()
.add_service(service)
.serve_with_incoming(incoming)
.await
.unwrap();
});
format!("http://{address}")
}
fn int_value(value: i32) -> MxValue {
MxValue {
data_type: MxDataType::Integer as i32,
variant_type: "VT_I4".to_owned(),
kind: Some(Kind::Int32Value(value)),
..MxValue::default()
}
}
fn ok_status(message: &str) -> ProtocolStatus {
ProtocolStatus {
code: ProtocolStatusCode::Ok as i32,
message: message.to_owned(),
}
}
fn mxaccess_failure_reply() -> MxCommandReply {
MxCommandReply {
session_id: "session-fixture".to_owned(),
correlation_id: "gateway-correlation-write-1".to_owned(),
kind: MxCommandKind::Write as i32,
protocol_status: Some(ProtocolStatus {
code: ProtocolStatusCode::MxaccessFailure as i32,
message: "MXAccess rejected the write.".to_owned(),
}),
hresult: Some(-2147220992),
statuses: vec![
MxStatusProxy {
success: 0,
category: MxStatusCategory::SecurityError as i32,
detected_by: MxStatusSource::RespondingLmx as i32,
detail: 321,
raw_category: 8,
raw_detected_by: 3,
diagnostic_text: "Write denied by provider security.".to_owned(),
},
MxStatusProxy {
success: 0,
category: MxStatusCategory::OperationalError as i32,
detected_by: MxStatusSource::RespondingNmx as i32,
detail: 902,
raw_category: 7,
raw_detected_by: 5,
diagnostic_text: "Provider rejected the item state.".to_owned(),
},
],
..MxCommandReply::default()
}
}
fn event(sequence: u64) -> MxEvent {
MxEvent {
family: MxEventFamily::OnDataChange as i32,
session_id: "session-fixture".to_owned(),
worker_sequence: sequence,
..MxEvent::default()
}
}
fn behavior_fixture(path: &str) -> Value {
let path = std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
.join("../proto/fixtures/behavior")
.join(path);
let data = std::fs::read_to_string(&path).unwrap();
serde_json::from_str(&data).unwrap()
}
fn case_by_id<'a>(cases: &'a [Value], id: &str) -> &'a Value {
cases
.iter()
.find(|case| case["id"].as_str() == Some(id))
.unwrap_or_else(|| panic!("missing fixture case {id}"))
}