oxicode 0.2.1

A modern binary serialization library - successor to bincode
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
//! Advanced async streaming tests (fifteenth set) for OxiCode.
//!
//! All 22 tests are top-level `#[tokio::test]` functions (no module wrapper).
//! Gated by the `async-tokio` feature at the file level.
//!
//! Types unique to this file: `Pipeline` and `PipelineStatus`.
//!
//! Coverage matrix:
//!   1:  Pipeline async roundtrip
//!   2:  PipelineStatus::Pending async roundtrip
//!   3:  PipelineStatus::Running async roundtrip
//!   4:  PipelineStatus::Completed async roundtrip
//!   5:  PipelineStatus::Failed async roundtrip
//!   6:  u32 async roundtrip
//!   7:  String async roundtrip
//!   8:  Vec<u8> async roundtrip
//!   9:  bool true async roundtrip
//!  10:  bool false async roundtrip
//!  11:  u64 async roundtrip
//!  12:  f32 async roundtrip
//!  13:  f64 async roundtrip
//!  14:  Option<String> Some async roundtrip
//!  15:  Option<String> None async roundtrip
//!  16:  Vec<Pipeline> 3-item async roundtrip
//!  17:  Vec<PipelineStatus> 4-variant async roundtrip
//!  18:  i32 negative async roundtrip
//!  19:  Empty Vec<u8> async roundtrip
//!  20:  Large Vec<u8> 1000 bytes async roundtrip
//!  21:  Tuple (u32, String) async roundtrip
//!  22:  Sequential writes — write 3 values, read back 3 values

#![cfg(feature = "async-tokio")]
#![allow(
    clippy::approx_constant,
    clippy::useless_vec,
    clippy::len_zero,
    clippy::unnecessary_cast,
    clippy::redundant_closure,
    clippy::too_many_arguments,
    clippy::type_complexity,
    clippy::needless_borrow,
    clippy::enum_variant_names,
    clippy::upper_case_acronyms,
    clippy::inconsistent_digit_grouping,
    clippy::unit_cmp,
    clippy::assertions_on_constants,
    clippy::iter_on_single_items,
    clippy::expect_fun_call,
    clippy::redundant_pattern_matching,
    variant_size_differences,
    clippy::absurd_extreme_comparisons,
    clippy::nonminimal_bool,
    clippy::for_kv_map,
    clippy::needless_range_loop,
    clippy::single_match,
    clippy::collapsible_if,
    clippy::needless_return,
    clippy::redundant_clone,
    clippy::map_entry,
    clippy::match_single_binding,
    clippy::bool_comparison,
    clippy::derivable_impls,
    clippy::manual_range_contains,
    clippy::needless_borrows_for_generic_args,
    clippy::manual_map,
    clippy::vec_init_then_push,
    clippy::identity_op,
    clippy::manual_flatten,
    clippy::single_char_pattern,
    clippy::search_is_some,
    clippy::option_map_unit_fn,
    clippy::while_let_on_iterator,
    clippy::clone_on_copy,
    clippy::box_collection,
    clippy::redundant_field_names,
    clippy::ptr_arg,
    clippy::large_enum_variant,
    clippy::match_ref_pats,
    clippy::needless_pass_by_value,
    clippy::unused_unit,
    clippy::let_and_return,
    clippy::suspicious_else_formatting,
    clippy::manual_strip,
    clippy::match_like_matches_macro,
    clippy::from_over_into,
    clippy::wrong_self_convention,
    clippy::inherent_to_string,
    clippy::new_without_default,
    clippy::unnecessary_wraps,
    clippy::field_reassign_with_default,
    clippy::manual_find,
    clippy::unnecessary_lazy_evaluations,
    clippy::should_implement_trait,
    clippy::missing_safety_doc,
    clippy::unusual_byte_groupings,
    clippy::bool_assert_comparison,
    clippy::zero_prefixed_literal,
    clippy::await_holding_lock,
    clippy::manual_saturating_arithmetic,
    clippy::explicit_counter_loop,
    clippy::needless_lifetimes,
    clippy::single_component_path_imports,
    clippy::uninlined_format_args,
    clippy::iter_cloned_collect,
    clippy::manual_str_repeat,
    clippy::excessive_precision,
    clippy::precedence,
    clippy::unnecessary_literal_unwrap
)]
use oxicode::async_tokio::{AsyncDecoder, AsyncEncoder};
use oxicode::{Decode, Encode};
use std::io::Cursor;
use tokio::io::BufReader;

// ---------------------------------------------------------------------------
// Types unique to this file
// ---------------------------------------------------------------------------

#[derive(Debug, PartialEq, Encode, Decode)]
struct Pipeline {
    id: u32,
    name: String,
    stages: Vec<String>,
    enabled: bool,
}

#[derive(Debug, PartialEq, Encode, Decode)]
enum PipelineStatus {
    Pending,
    Running(u32),
    Completed { duration_ms: u64 },
    Failed(String),
}

// ---------------------------------------------------------------------------
// Test 1: Pipeline async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_pipeline_roundtrip() {
    let val = Pipeline {
        id: 1,
        name: String::from("build-and-test"),
        stages: vec![
            String::from("checkout"),
            String::from("build"),
            String::from("test"),
        ],
        enabled: true,
    };

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write Pipeline");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Pipeline = dec
        .read_item()
        .await
        .expect("read Pipeline")
        .expect("expected Some(Pipeline)");

    assert_eq!(val, decoded, "Pipeline async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 2: PipelineStatus::Pending async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_pipeline_status_pending_roundtrip() {
    let val = PipelineStatus::Pending;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write PipelineStatus::Pending");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: PipelineStatus = dec
        .read_item()
        .await
        .expect("read PipelineStatus::Pending")
        .expect("expected Some(PipelineStatus)");

    assert_eq!(
        val, decoded,
        "PipelineStatus::Pending async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 3: PipelineStatus::Running async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_pipeline_status_running_roundtrip() {
    let val = PipelineStatus::Running(42);

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write PipelineStatus::Running");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: PipelineStatus = dec
        .read_item()
        .await
        .expect("read PipelineStatus::Running")
        .expect("expected Some(PipelineStatus)");

    assert_eq!(
        val, decoded,
        "PipelineStatus::Running async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 4: PipelineStatus::Completed async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_pipeline_status_completed_roundtrip() {
    let val = PipelineStatus::Completed {
        duration_ms: 12_345_678,
    };

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write PipelineStatus::Completed");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: PipelineStatus = dec
        .read_item()
        .await
        .expect("read PipelineStatus::Completed")
        .expect("expected Some(PipelineStatus)");

    assert_eq!(
        val, decoded,
        "PipelineStatus::Completed async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 5: PipelineStatus::Failed async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_pipeline_status_failed_roundtrip() {
    let val = PipelineStatus::Failed(String::from("out of memory during build step"));

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write PipelineStatus::Failed");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: PipelineStatus = dec
        .read_item()
        .await
        .expect("read PipelineStatus::Failed")
        .expect("expected Some(PipelineStatus)");

    assert_eq!(
        val, decoded,
        "PipelineStatus::Failed async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 6: u32 async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_u32_roundtrip() {
    let val: u32 = 3_141_592_653;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write u32");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: u32 = dec
        .read_item()
        .await
        .expect("read u32")
        .expect("expected Some(u32)");

    assert_eq!(val, decoded, "u32 async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 7: String async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_string_roundtrip() {
    let val = String::from("oxicode-async-pipeline-wave15");

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write String");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: String = dec
        .read_item()
        .await
        .expect("read String")
        .expect("expected Some(String)");

    assert_eq!(val, decoded, "String async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 8: Vec<u8> async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_vec_u8_roundtrip() {
    let val: Vec<u8> = vec![10, 20, 30, 40, 50, 60, 70, 80];

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write Vec<u8>");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Vec<u8> = dec
        .read_item()
        .await
        .expect("read Vec<u8>")
        .expect("expected Some(Vec<u8>)");

    assert_eq!(val, decoded, "Vec<u8> async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 9: bool true async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_bool_true_roundtrip() {
    let val: bool = true;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write bool true");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: bool = dec
        .read_item()
        .await
        .expect("read bool true")
        .expect("expected Some(bool)");

    assert_eq!(val, decoded, "bool true async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 10: bool false async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_bool_false_roundtrip() {
    let val: bool = false;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write bool false");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: bool = dec
        .read_item()
        .await
        .expect("read bool false")
        .expect("expected Some(bool)");

    assert_eq!(val, decoded, "bool false async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 11: u64 async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_u64_roundtrip() {
    let val: u64 = 18_446_744_073_709_551_000;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write u64");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: u64 = dec
        .read_item()
        .await
        .expect("read u64")
        .expect("expected Some(u64)");

    assert_eq!(val, decoded, "u64 async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 12: f32 async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_f32_roundtrip() {
    let val: f32 = std::f32::consts::PI;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write f32");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: f32 = dec
        .read_item()
        .await
        .expect("read f32")
        .expect("expected Some(f32)");

    assert_eq!(
        val.to_bits(),
        decoded.to_bits(),
        "f32 async roundtrip bit mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 13: f64 async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_f64_roundtrip() {
    let val: f64 = std::f64::consts::E;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write f64");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: f64 = dec
        .read_item()
        .await
        .expect("read f64")
        .expect("expected Some(f64)");

    assert_eq!(
        val.to_bits(),
        decoded.to_bits(),
        "f64 async roundtrip bit mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 14: Option<String> Some async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_option_string_some_roundtrip() {
    let val: Option<String> = Some(String::from("pipeline-deploy-prod"));

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write Option<String> Some");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Option<String> = dec
        .read_item()
        .await
        .expect("read Option<String> Some")
        .expect("expected Some(Option<String>)");

    assert_eq!(val, decoded, "Option<String> Some async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 15: Option<String> None async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_option_string_none_roundtrip() {
    let val: Option<String> = None;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write Option<String> None");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Option<String> = dec
        .read_item()
        .await
        .expect("read Option<String> None")
        .expect("expected Some(Option<String>)");

    assert_eq!(val, decoded, "Option<String> None async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 16: Vec<Pipeline> 3-item async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_vec_pipeline_three_roundtrip() {
    let val: Vec<Pipeline> = vec![
        Pipeline {
            id: 100,
            name: String::from("ci-pipeline"),
            stages: vec![String::from("lint"), String::from("test")],
            enabled: true,
        },
        Pipeline {
            id: 200,
            name: String::from("cd-pipeline"),
            stages: vec![
                String::from("build"),
                String::from("push"),
                String::from("deploy"),
            ],
            enabled: true,
        },
        Pipeline {
            id: 300,
            name: String::from("nightly-pipeline"),
            stages: vec![String::from("benchmark"), String::from("report")],
            enabled: false,
        },
    ];

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write Vec<Pipeline>");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Vec<Pipeline> = dec
        .read_item()
        .await
        .expect("read Vec<Pipeline>")
        .expect("expected Some(Vec<Pipeline>)");

    assert_eq!(
        val, decoded,
        "Vec<Pipeline> 3-item async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 17: Vec<PipelineStatus> 4-variant async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_vec_pipeline_status_four_variants_roundtrip() {
    let val: Vec<PipelineStatus> = vec![
        PipelineStatus::Pending,
        PipelineStatus::Running(7),
        PipelineStatus::Completed {
            duration_ms: 98_765,
        },
        PipelineStatus::Failed(String::from("network timeout")),
    ];

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val)
        .await
        .expect("write Vec<PipelineStatus>");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Vec<PipelineStatus> = dec
        .read_item()
        .await
        .expect("read Vec<PipelineStatus>")
        .expect("expected Some(Vec<PipelineStatus>)");

    assert_eq!(
        val, decoded,
        "Vec<PipelineStatus> 4-variant async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 18: i32 negative async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_i32_negative_roundtrip() {
    let val: i32 = -2_147_483_647;

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write i32 negative");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: i32 = dec
        .read_item()
        .await
        .expect("read i32 negative")
        .expect("expected Some(i32)");

    assert_eq!(val, decoded, "i32 negative async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 19: Empty Vec<u8> async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_empty_vec_u8_roundtrip() {
    let val: Vec<u8> = Vec::new();

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write empty Vec<u8>");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Vec<u8> = dec
        .read_item()
        .await
        .expect("read empty Vec<u8>")
        .expect("expected Some(Vec<u8>)");

    assert_eq!(val, decoded, "empty Vec<u8> async roundtrip mismatch");
    assert!(decoded.is_empty(), "decoded Vec<u8> must be empty");
}

// ---------------------------------------------------------------------------
// Test 20: Large Vec<u8> 1000 bytes async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_large_vec_u8_1000_bytes_roundtrip() {
    let val: Vec<u8> = (0u8..=255).cycle().take(1000).collect();
    assert_eq!(val.len(), 1000, "test data must be exactly 1000 bytes");

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write large Vec<u8>");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: Vec<u8> = dec
        .read_item()
        .await
        .expect("read large Vec<u8>")
        .expect("expected Some(Vec<u8>)");

    assert_eq!(
        val, decoded,
        "large Vec<u8> (1000 bytes) async roundtrip mismatch"
    );
}

// ---------------------------------------------------------------------------
// Test 21: Tuple (u32, String) async roundtrip
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_tuple_u32_string_roundtrip() {
    let val: (u32, String) = (9_999, String::from("pipeline-stage-label"));

    let mut buf = Vec::<u8>::new();
    let mut enc = AsyncEncoder::new(&mut buf);
    enc.write_item(&val).await.expect("write (u32, String)");
    enc.finish().await.expect("finish encoder");

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);
    let decoded: (u32, String) = dec
        .read_item()
        .await
        .expect("read (u32, String)")
        .expect("expected Some((u32, String))");

    assert_eq!(val, decoded, "(u32, String) async roundtrip mismatch");
}

// ---------------------------------------------------------------------------
// Test 22: Sequential writes — write 3 values, read back 3 values
// ---------------------------------------------------------------------------

#[tokio::test]
async fn test_async15_sequential_three_values_roundtrip() {
    let pipeline = Pipeline {
        id: 55,
        name: String::from("integration-tests"),
        stages: vec![
            String::from("setup"),
            String::from("run"),
            String::from("teardown"),
        ],
        enabled: true,
    };
    let status = PipelineStatus::Completed { duration_ms: 4_200 };
    let count: u32 = 777;

    let mut buf = Vec::<u8>::new();
    {
        let mut enc = AsyncEncoder::new(&mut buf);
        enc.write_item(&pipeline).await.expect("write Pipeline");
        enc.write_item(&status).await.expect("write PipelineStatus");
        enc.write_item(&count).await.expect("write u32");
        enc.finish().await.expect("finish encoder");
    }

    let cursor = Cursor::new(buf);
    let mut reader = BufReader::new(cursor);
    let mut dec = AsyncDecoder::new(&mut reader);

    let decoded_pipeline: Pipeline = dec
        .read_item()
        .await
        .expect("read Pipeline")
        .expect("expected Some(Pipeline)");
    let decoded_status: PipelineStatus = dec
        .read_item()
        .await
        .expect("read PipelineStatus")
        .expect("expected Some(PipelineStatus)");
    let decoded_count: u32 = dec
        .read_item()
        .await
        .expect("read u32")
        .expect("expected Some(u32)");

    assert_eq!(
        pipeline, decoded_pipeline,
        "sequential read: Pipeline mismatch"
    );
    assert_eq!(
        status, decoded_status,
        "sequential read: PipelineStatus mismatch"
    );
    assert_eq!(count, decoded_count, "sequential read: u32 mismatch");

    let eof: Option<u32> = dec.read_item().await.expect("read after end of stream");
    assert_eq!(eof, None, "expected None after all 3 values decoded");
}