1use super::{Format, FormatEvent, FormatFields, FormatTime, Writer};
2use crate::{
3 field::{RecordFields, VisitOutput},
4 fmt::{
5 fmt_layer::{FmtContext, FormattedFields},
6 writer::WriteAdaptor,
7 },
8 registry::LookupSpan,
9};
10use serde::ser::{SerializeMap, Serializer as _};
11use serde_json::Serializer;
12use std::{
13 collections::BTreeMap,
14 fmt::{self, Write},
15};
16use tracing_core::{
17 field::{self, Field},
18 span::Record,
19 Event, Subscriber,
20};
21use tracing_serde::AsSerde;
22
23#[cfg(feature = "tracing-log")]
24use tracing_log::NormalizeEvent;
25
26#[derive(Debug, Copy, Clone, Eq, PartialEq)]
90pub struct Json {
91 pub(crate) flatten_event: bool,
92 pub(crate) display_current_span: bool,
93 pub(crate) display_span_list: bool,
94}
95
96impl Json {
97 pub fn flatten_event(&mut self, flatten_event: bool) {
99 self.flatten_event = flatten_event;
100 }
101
102 pub fn with_current_span(&mut self, display_current_span: bool) {
104 self.display_current_span = display_current_span;
105 }
106
107 pub fn with_span_list(&mut self, display_span_list: bool) {
110 self.display_span_list = display_span_list;
111 }
112}
113
114struct SerializableContext<'a, 'b, Span, N>(
115 &'b crate::layer::Context<'a, Span>,
116 std::marker::PhantomData<N>,
117)
118where
119 Span: Subscriber + for<'lookup> crate::registry::LookupSpan<'lookup>,
120 N: for<'writer> FormatFields<'writer> + 'static;
121
122impl<Span, N> serde::ser::Serialize for SerializableContext<'_, '_, Span, N>
123where
124 Span: Subscriber + for<'lookup> crate::registry::LookupSpan<'lookup>,
125 N: for<'writer> FormatFields<'writer> + 'static,
126{
127 fn serialize<Ser>(&self, serializer_o: Ser) -> Result<Ser::Ok, Ser::Error>
128 where
129 Ser: serde::ser::Serializer,
130 {
131 use serde::ser::SerializeSeq;
132 let mut serializer = serializer_o.serialize_seq(None)?;
133
134 if let Some(leaf_span) = self.0.lookup_current() {
135 for span in leaf_span.scope().from_root() {
136 serializer.serialize_element(&SerializableSpan(&span, self.1))?;
137 }
138 }
139
140 serializer.end()
141 }
142}
143
144struct SerializableSpan<'a, 'b, Span, N>(
145 &'b crate::registry::SpanRef<'a, Span>,
146 std::marker::PhantomData<N>,
147)
148where
149 Span: for<'lookup> crate::registry::LookupSpan<'lookup>,
150 N: for<'writer> FormatFields<'writer> + 'static;
151
152impl<Span, N> serde::ser::Serialize for SerializableSpan<'_, '_, Span, N>
153where
154 Span: for<'lookup> crate::registry::LookupSpan<'lookup>,
155 N: for<'writer> FormatFields<'writer> + 'static,
156{
157 fn serialize<Ser>(&self, serializer: Ser) -> Result<Ser::Ok, Ser::Error>
158 where
159 Ser: serde::ser::Serializer,
160 {
161 let mut serializer = serializer.serialize_map(None)?;
162
163 let ext = self.0.extensions();
164 let data = ext
165 .get::<FormattedFields<N>>()
166 .expect("Unable to find FormattedFields in extensions; this is a bug");
167
168 match serde_json::from_str::<serde_json::Value>(data) {
174 Ok(serde_json::Value::Object(fields)) => {
175 for field in fields {
176 serializer.serialize_entry(&field.0, &field.1)?;
177 }
178 }
179 Ok(_) if cfg!(debug_assertions) => panic!(
182 "span '{}' had malformed fields! this is a bug.\n error: invalid JSON object\n fields: {:?}",
183 self.0.metadata().name(),
184 data
185 ),
186 Ok(value) => {
190 serializer.serialize_entry("field", &value)?;
191 serializer.serialize_entry("field_error", "field was no a valid object")?
192 }
193 Err(e) if cfg!(debug_assertions) => panic!(
198 "span '{}' had malformed fields! this is a bug.\n error: {}\n fields: {:?}",
199 self.0.metadata().name(),
200 e,
201 data
202 ),
203 Err(e) => serializer.serialize_entry("field_error", &format!("{}", e))?,
207 };
208 serializer.serialize_entry("name", self.0.metadata().name())?;
209 serializer.end()
210 }
211}
212
213impl<S, N, T> FormatEvent<S, N> for Format<Json, T>
214where
215 S: Subscriber + for<'lookup> LookupSpan<'lookup>,
216 N: for<'writer> FormatFields<'writer> + 'static,
217 T: FormatTime,
218{
219 fn format_event(
220 &self,
221 ctx: &FmtContext<'_, S, N>,
222 mut writer: Writer<'_>,
223 event: &Event<'_>,
224 ) -> fmt::Result
225 where
226 S: Subscriber + for<'a> LookupSpan<'a>,
227 {
228 let mut timestamp = String::new();
229 self.timer.format_time(&mut Writer::new(&mut timestamp))?;
230
231 #[cfg(feature = "tracing-log")]
232 let normalized_meta = event.normalized_metadata();
233 #[cfg(feature = "tracing-log")]
234 let meta = normalized_meta.as_ref().unwrap_or_else(|| event.metadata());
235 #[cfg(not(feature = "tracing-log"))]
236 let meta = event.metadata();
237
238 let mut visit = || {
239 let mut serializer = Serializer::new(WriteAdaptor::new(&mut writer));
240
241 let mut serializer = serializer.serialize_map(None)?;
242
243 if self.display_timestamp {
244 serializer.serialize_entry("timestamp", ×tamp)?;
245 }
246
247 if self.display_level {
248 serializer.serialize_entry("level", &meta.level().as_serde())?;
249 }
250
251 let format_field_marker: std::marker::PhantomData<N> = std::marker::PhantomData;
252
253 let current_span = if self.format.display_current_span || self.format.display_span_list
254 {
255 event
256 .parent()
257 .and_then(|id| ctx.span(id))
258 .or_else(|| ctx.lookup_current())
259 } else {
260 None
261 };
262
263 if self.format.flatten_event {
264 let mut visitor = tracing_serde::SerdeMapVisitor::new(serializer);
265 event.record(&mut visitor);
266
267 serializer = visitor.take_serializer()?;
268 } else {
269 use tracing_serde::fields::AsMap;
270 serializer.serialize_entry("fields", &event.field_map())?;
271 };
272
273 if self.display_target {
274 serializer.serialize_entry("target", meta.target())?;
275 }
276
277 if self.display_filename {
278 if let Some(filename) = meta.file() {
279 serializer.serialize_entry("filename", filename)?;
280 }
281 }
282
283 if self.display_line_number {
284 if let Some(line_number) = meta.line() {
285 serializer.serialize_entry("line_number", &line_number)?;
286 }
287 }
288
289 if self.format.display_current_span {
290 if let Some(ref span) = current_span {
291 serializer
292 .serialize_entry("span", &SerializableSpan(span, format_field_marker))
293 .unwrap_or(());
294 }
295 }
296
297 if self.format.display_span_list && current_span.is_some() {
298 serializer.serialize_entry(
299 "spans",
300 &SerializableContext(&ctx.ctx, format_field_marker),
301 )?;
302 }
303
304 if self.display_thread_name {
305 let current_thread = std::thread::current();
306 match current_thread.name() {
307 Some(name) => {
308 serializer.serialize_entry("threadName", name)?;
309 }
310 None if !self.display_thread_id => {
312 serializer
313 .serialize_entry("threadName", &format!("{:?}", current_thread.id()))?;
314 }
315 _ => {}
316 }
317 }
318
319 if self.display_thread_id {
320 serializer
321 .serialize_entry("threadId", &format!("{:?}", std::thread::current().id()))?;
322 }
323
324 serializer.end()
325 };
326
327 visit().map_err(|_| fmt::Error)?;
328 writeln!(writer)
329 }
330}
331
332impl Default for Json {
333 fn default() -> Json {
334 Json {
335 flatten_event: false,
336 display_current_span: true,
337 display_span_list: true,
338 }
339 }
340}
341
342#[derive(Debug)]
345pub struct JsonFields {
346 _private: (),
349}
350
351impl JsonFields {
352 pub fn new() -> Self {
355 Self { _private: () }
356 }
357}
358
359impl Default for JsonFields {
360 fn default() -> Self {
361 Self::new()
362 }
363}
364
365impl<'a> FormatFields<'a> for JsonFields {
366 fn format_fields<R: RecordFields>(&self, mut writer: Writer<'_>, fields: R) -> fmt::Result {
368 let mut v = JsonVisitor::new(&mut writer);
369 fields.record(&mut v);
370 v.finish()
371 }
372
373 fn add_fields(
379 &self,
380 current: &'a mut FormattedFields<Self>,
381 fields: &Record<'_>,
382 ) -> fmt::Result {
383 if current.is_empty() {
384 let mut writer = current.as_writer();
387 let mut v = JsonVisitor::new(&mut writer);
388 fields.record(&mut v);
389 v.finish()?;
390 return Ok(());
391 }
392
393 let mut new = String::new();
408 let map: BTreeMap<&'_ str, serde_json::Value> =
409 serde_json::from_str(current).map_err(|_| fmt::Error)?;
410 let mut v = JsonVisitor::new(&mut new);
411 v.values = map;
412 fields.record(&mut v);
413 v.finish()?;
414 current.fields = new;
415
416 Ok(())
417 }
418}
419
420pub struct JsonVisitor<'a> {
425 values: BTreeMap<&'a str, serde_json::Value>,
426 writer: &'a mut dyn Write,
427}
428
429impl fmt::Debug for JsonVisitor<'_> {
430 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
431 f.write_fmt(format_args!("JsonVisitor {{ values: {:?} }}", self.values))
432 }
433}
434
435impl<'a> JsonVisitor<'a> {
436 pub fn new(writer: &'a mut dyn Write) -> Self {
443 Self {
444 values: BTreeMap::new(),
445 writer,
446 }
447 }
448}
449
450impl crate::field::VisitFmt for JsonVisitor<'_> {
451 fn writer(&mut self) -> &mut dyn fmt::Write {
452 self.writer
453 }
454}
455
456impl crate::field::VisitOutput<fmt::Result> for JsonVisitor<'_> {
457 fn finish(self) -> fmt::Result {
458 let inner = || {
459 let mut serializer = Serializer::new(WriteAdaptor::new(self.writer));
460 let mut ser_map = serializer.serialize_map(None)?;
461
462 for (k, v) in self.values {
463 ser_map.serialize_entry(k, &v)?;
464 }
465
466 ser_map.end()
467 };
468
469 if inner().is_err() {
470 Err(fmt::Error)
471 } else {
472 Ok(())
473 }
474 }
475}
476
477impl field::Visit for JsonVisitor<'_> {
478 #[cfg(all(tracing_unstable, feature = "valuable"))]
479 fn record_value(&mut self, field: &Field, value: valuable_crate::Value<'_>) {
480 let value = match serde_json::to_value(valuable_serde::Serializable::new(value)) {
481 Ok(value) => value,
482 Err(_e) => {
483 #[cfg(debug_assertions)]
484 unreachable!(
485 "`valuable::Valuable` implementations should always serialize \
486 successfully, but an error occurred: {}",
487 _e,
488 );
489
490 #[cfg(not(debug_assertions))]
491 return;
492 }
493 };
494
495 self.values.insert(field.name(), value);
496 }
497
498 fn record_f64(&mut self, field: &Field, value: f64) {
500 self.values
501 .insert(field.name(), serde_json::Value::from(value));
502 }
503
504 fn record_i64(&mut self, field: &Field, value: i64) {
506 self.values
507 .insert(field.name(), serde_json::Value::from(value));
508 }
509
510 fn record_u64(&mut self, field: &Field, value: u64) {
512 self.values
513 .insert(field.name(), serde_json::Value::from(value));
514 }
515
516 fn record_bool(&mut self, field: &Field, value: bool) {
518 self.values
519 .insert(field.name(), serde_json::Value::from(value));
520 }
521
522 fn record_str(&mut self, field: &Field, value: &str) {
524 self.values
525 .insert(field.name(), serde_json::Value::from(value));
526 }
527
528 fn record_bytes(&mut self, field: &Field, value: &[u8]) {
529 self.values
530 .insert(field.name(), serde_json::Value::from(value));
531 }
532
533 fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug) {
534 match field.name() {
535 #[cfg(feature = "tracing-log")]
537 name if name.starts_with("log.") => (),
538 name if name.starts_with("r#") => {
539 self.values
540 .insert(&name[2..], serde_json::Value::from(format!("{:?}", value)));
541 }
542 name => {
543 self.values
544 .insert(name, serde_json::Value::from(format!("{:?}", value)));
545 }
546 };
547 }
548}
549#[cfg(test)]
550mod test {
551 use super::*;
552 use crate::fmt::{format::FmtSpan, test::MockMakeWriter, time::FormatTime, SubscriberBuilder};
553 use tracing::{self, subscriber::with_default};
554
555 use std::fmt;
556 use std::path::Path;
557
558 struct MockTime;
559 impl FormatTime for MockTime {
560 fn format_time(&self, w: &mut Writer<'_>) -> fmt::Result {
561 write!(w, "fake time")
562 }
563 }
564
565 fn subscriber() -> SubscriberBuilder<JsonFields, Format<Json>> {
566 SubscriberBuilder::default().json()
567 }
568
569 #[test]
570 fn json() {
571 let expected =
572 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"span\":{\"answer\":42,\"name\":\"json_span\",\"number\":3,\"slice\":[97,98,99]},\"spans\":[{\"answer\":42,\"name\":\"json_span\",\"number\":3,\"slice\":[97,98,99]}],\"target\":\"better_tracing::fmt::format::json::test\",\"fields\":{\"message\":\"some json test\"}}\n";
573 let subscriber = subscriber()
574 .flatten_event(false)
575 .with_current_span(true)
576 .with_span_list(true);
577 test_json(expected, subscriber, || {
578 let span = tracing::span!(
579 tracing::Level::INFO,
580 "json_span",
581 answer = 42,
582 number = 3,
583 slice = &b"abc"[..]
584 );
585 let _guard = span.enter();
586 tracing::info!("some json test");
587 });
588 }
589
590 #[test]
591 fn json_filename() {
592 let current_path = Path::new("src")
593 .join("fmt")
594 .join("format")
595 .join("json.rs")
596 .to_str()
597 .expect("path must be valid unicode")
598 .replace('\\', "\\\\");
600 let expected =
601 &format!("{}{}{}",
602 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"span\":{\"answer\":42,\"name\":\"json_span\",\"number\":3},\"spans\":[{\"answer\":42,\"name\":\"json_span\",\"number\":3}],\"target\":\"better_tracing::fmt::format::json::test\",\"filename\":\"",
603 current_path,
604 "\",\"fields\":{\"message\":\"some json test\"}}\n");
605 let subscriber = subscriber()
606 .flatten_event(false)
607 .with_current_span(true)
608 .with_file(true)
609 .with_span_list(true);
610 test_json(expected, subscriber, || {
611 let span = tracing::span!(tracing::Level::INFO, "json_span", answer = 42, number = 3);
612 let _guard = span.enter();
613 tracing::info!("some json test");
614 });
615 }
616
617 #[test]
618 fn json_line_number() {
619 let expected =
620 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"span\":{\"answer\":42,\"name\":\"json_span\",\"number\":3},\"spans\":[{\"answer\":42,\"name\":\"json_span\",\"number\":3}],\"target\":\"better_tracing::fmt::format::json::test\",\"line_number\":42,\"fields\":{\"message\":\"some json test\"}}\n";
621 let subscriber = subscriber()
622 .flatten_event(false)
623 .with_current_span(true)
624 .with_line_number(true)
625 .with_span_list(true);
626 test_json_with_line_number(expected, subscriber, || {
627 let span = tracing::span!(tracing::Level::INFO, "json_span", answer = 42, number = 3);
628 let _guard = span.enter();
629 tracing::info!("some json test");
630 });
631 }
632
633 #[test]
634 fn json_flattened_event() {
635 let expected =
636 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"span\":{\"answer\":42,\"name\":\"json_span\",\"number\":3},\"spans\":[{\"answer\":42,\"name\":\"json_span\",\"number\":3}],\"target\":\"better_tracing::fmt::format::json::test\",\"message\":\"some json test\"}\n";
637
638 let subscriber = subscriber()
639 .flatten_event(true)
640 .with_current_span(true)
641 .with_span_list(true);
642 test_json(expected, subscriber, || {
643 let span = tracing::span!(tracing::Level::INFO, "json_span", answer = 42, number = 3);
644 let _guard = span.enter();
645 tracing::info!("some json test");
646 });
647 }
648
649 #[test]
650 fn json_disabled_current_span_event() {
651 let expected =
652 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"spans\":[{\"answer\":42,\"name\":\"json_span\",\"number\":3}],\"target\":\"better_tracing::fmt::format::json::test\",\"fields\":{\"message\":\"some json test\"}}\n";
653 let subscriber = subscriber()
654 .flatten_event(false)
655 .with_current_span(false)
656 .with_span_list(true);
657 test_json(expected, subscriber, || {
658 let span = tracing::span!(tracing::Level::INFO, "json_span", answer = 42, number = 3);
659 let _guard = span.enter();
660 tracing::info!("some json test");
661 });
662 }
663
664 #[test]
665 fn json_disabled_span_list_event() {
666 let expected =
667 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"span\":{\"answer\":42,\"name\":\"json_span\",\"number\":3},\"target\":\"better_tracing::fmt::format::json::test\",\"fields\":{\"message\":\"some json test\"}}\n";
668 let subscriber = subscriber()
669 .flatten_event(false)
670 .with_current_span(true)
671 .with_span_list(false);
672 test_json(expected, subscriber, || {
673 let span = tracing::span!(tracing::Level::INFO, "json_span", answer = 42, number = 3);
674 let _guard = span.enter();
675 tracing::info!("some json test");
676 });
677 }
678
679 #[test]
680 fn json_nested_span() {
681 let expected =
682 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"span\":{\"answer\":43,\"name\":\"nested_json_span\",\"number\":4},\"spans\":[{\"answer\":42,\"name\":\"json_span\",\"number\":3},{\"answer\":43,\"name\":\"nested_json_span\",\"number\":4}],\"target\":\"better_tracing::fmt::format::json::test\",\"fields\":{\"message\":\"some json test\"}}\n";
683 let subscriber = subscriber()
684 .flatten_event(false)
685 .with_current_span(true)
686 .with_span_list(true);
687 test_json(expected, subscriber, || {
688 let span = tracing::span!(tracing::Level::INFO, "json_span", answer = 42, number = 3);
689 let _guard = span.enter();
690 let span = tracing::span!(
691 tracing::Level::INFO,
692 "nested_json_span",
693 answer = 43,
694 number = 4
695 );
696 let _guard = span.enter();
697 tracing::info!("some json test");
698 });
699 }
700
701 #[test]
702 fn json_no_span() {
703 let expected =
704 "{\"timestamp\":\"fake time\",\"level\":\"INFO\",\"target\":\"better_tracing::fmt::format::json::test\",\"fields\":{\"message\":\"some json test\"}}\n";
705 let subscriber = subscriber()
706 .flatten_event(false)
707 .with_current_span(true)
708 .with_span_list(true);
709 test_json(expected, subscriber, || {
710 tracing::info!("some json test");
711 });
712 }
713
714 #[test]
715 fn record_works() {
716 let make_writer = MockMakeWriter::default();
720 let subscriber = crate::fmt()
721 .json()
722 .with_writer(make_writer.clone())
723 .finish();
724
725 with_default(subscriber, || {
726 tracing::info!("an event outside the root span");
727 assert_eq!(
728 parse_as_json(&make_writer)["fields"]["message"],
729 "an event outside the root span"
730 );
731
732 let span = tracing::info_span!("the span", na = tracing::field::Empty);
733 span.record("na", "value");
734 let _enter = span.enter();
735
736 tracing::info!("an event inside the root span");
737 assert_eq!(
738 parse_as_json(&make_writer)["fields"]["message"],
739 "an event inside the root span"
740 );
741 });
742 }
743
744 #[test]
745 fn json_span_event_show_correct_context() {
746 let buffer = MockMakeWriter::default();
747 let subscriber = subscriber()
748 .with_writer(buffer.clone())
749 .flatten_event(false)
750 .with_current_span(true)
751 .with_span_list(false)
752 .with_span_events(FmtSpan::FULL)
753 .finish();
754
755 with_default(subscriber, || {
756 let context = "parent";
757 let parent_span = tracing::info_span!("parent_span", context);
758
759 let event = parse_as_json(&buffer);
760 assert_eq!(event["fields"]["message"], "new");
761 assert_eq!(event["span"]["context"], "parent");
762
763 let _parent_enter = parent_span.enter();
764 let event = parse_as_json(&buffer);
765 assert_eq!(event["fields"]["message"], "enter");
766 assert_eq!(event["span"]["context"], "parent");
767
768 let context = "child";
769 let child_span = tracing::info_span!("child_span", context);
770 let event = parse_as_json(&buffer);
771 assert_eq!(event["fields"]["message"], "new");
772 assert_eq!(event["span"]["context"], "child");
773
774 let _child_enter = child_span.enter();
775 let event = parse_as_json(&buffer);
776 assert_eq!(event["fields"]["message"], "enter");
777 assert_eq!(event["span"]["context"], "child");
778
779 drop(_child_enter);
780 let event = parse_as_json(&buffer);
781 assert_eq!(event["fields"]["message"], "exit");
782 assert_eq!(event["span"]["context"], "child");
783
784 drop(child_span);
785 let event = parse_as_json(&buffer);
786 assert_eq!(event["fields"]["message"], "close");
787 assert_eq!(event["span"]["context"], "child");
788
789 drop(_parent_enter);
790 let event = parse_as_json(&buffer);
791 assert_eq!(event["fields"]["message"], "exit");
792 assert_eq!(event["span"]["context"], "parent");
793
794 drop(parent_span);
795 let event = parse_as_json(&buffer);
796 assert_eq!(event["fields"]["message"], "close");
797 assert_eq!(event["span"]["context"], "parent");
798 });
799 }
800
801 #[test]
802 fn json_span_event_with_no_fields() {
803 let buffer = MockMakeWriter::default();
806 let subscriber = subscriber()
807 .with_writer(buffer.clone())
808 .flatten_event(false)
809 .with_current_span(false)
810 .with_span_list(false)
811 .with_span_events(FmtSpan::FULL)
812 .finish();
813
814 with_default(subscriber, || {
815 let span = tracing::info_span!("valid_json");
816 assert_eq!(parse_as_json(&buffer)["fields"]["message"], "new");
817
818 let _enter = span.enter();
819 assert_eq!(parse_as_json(&buffer)["fields"]["message"], "enter");
820
821 drop(_enter);
822 assert_eq!(parse_as_json(&buffer)["fields"]["message"], "exit");
823
824 drop(span);
825 assert_eq!(parse_as_json(&buffer)["fields"]["message"], "close");
826 });
827 }
828
829 fn parse_as_json(buffer: &MockMakeWriter) -> serde_json::Value {
830 let buf = String::from_utf8(buffer.buf().to_vec()).unwrap();
831 let json = buf
832 .lines()
833 .last()
834 .expect("expected at least one line to be written!");
835 match serde_json::from_str(json) {
836 Ok(v) => v,
837 Err(e) => panic!(
838 "assertion failed: JSON shouldn't be malformed\n error: {}\n json: {}",
839 e, json
840 ),
841 }
842 }
843
844 fn test_json<T>(
845 expected: &str,
846 builder: crate::fmt::SubscriberBuilder<JsonFields, Format<Json>>,
847 producer: impl FnOnce() -> T,
848 ) {
849 let make_writer = MockMakeWriter::default();
850 let subscriber = builder
851 .with_writer(make_writer.clone())
852 .with_timer(MockTime)
853 .finish();
854
855 with_default(subscriber, producer);
856
857 let buf = make_writer.buf();
858 let actual = std::str::from_utf8(&buf[..]).unwrap();
859 assert_eq!(
860 serde_json::from_str::<std::collections::HashMap<&str, serde_json::Value>>(expected)
861 .unwrap(),
862 serde_json::from_str(actual).unwrap()
863 );
864 }
865
866 fn test_json_with_line_number<T>(
867 expected: &str,
868 builder: crate::fmt::SubscriberBuilder<JsonFields, Format<Json>>,
869 producer: impl FnOnce() -> T,
870 ) {
871 let make_writer = MockMakeWriter::default();
872 let subscriber = builder
873 .with_writer(make_writer.clone())
874 .with_timer(MockTime)
875 .finish();
876
877 with_default(subscriber, producer);
878
879 let buf = make_writer.buf();
880 let actual = std::str::from_utf8(&buf[..]).unwrap();
881 let mut expected =
882 serde_json::from_str::<std::collections::HashMap<&str, serde_json::Value>>(expected)
883 .unwrap();
884 let expect_line_number = expected.remove("line_number").is_some();
885 let mut actual: std::collections::HashMap<&str, serde_json::Value> =
886 serde_json::from_str(actual).unwrap();
887 let line_number = actual.remove("line_number");
888 if expect_line_number {
889 assert_eq!(line_number.map(|x| x.is_number()), Some(true));
890 } else {
891 assert!(line_number.is_none());
892 }
893 assert_eq!(actual, expected);
894 }
895}