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
//! Advanced async streaming tests (second set) for OxiCode.
//!
//! Covers unique scenarios not present in async_streaming_test.rs,
//! async_advanced_test.rs, async_comprehensive_test.rs, or async_extended_test.rs.

#![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
)]
#[cfg(feature = "async-tokio")]
use oxicode::streaming::{AsyncStreamingDecoder, AsyncStreamingEncoder, StreamingConfig};
#[cfg(feature = "async-tokio")]
use oxicode::{Decode, Encode};
#[cfg(feature = "async-tokio")]
use std::io::Cursor;

// ---------------------------------------------------------------------------
// Shared types (only compiled when async-tokio feature is active)
// ---------------------------------------------------------------------------

#[cfg(feature = "async-tokio")]
#[derive(Debug, Clone, PartialEq, Encode, Decode)]
struct Point2D {
    x: i32,
    y: i32,
}

#[cfg(feature = "async-tokio")]
#[derive(Debug, Clone, PartialEq, Encode, Decode)]
enum Direction {
    North,
    South,
    East,
    West,
}

// ---------------------------------------------------------------------------
// Test 1: Write then read single u32
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_single_u32_roundtrip() {
    let value: u32 = 0xDEAD_BEEF;

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder.write_item(&value).await.expect("write_item failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got: Option<u32> = decoder.read_item().await.expect("read_item failed");
    assert_eq!(got, Some(value));
    let eof: Option<u32> = decoder.read_item().await.expect("read after eof failed");
    assert!(eof.is_none());
}

// ---------------------------------------------------------------------------
// Test 2: Write then read multiple u32 values, verify all values and order
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_multiple_u32_values() {
    let values: Vec<u32> = vec![1, 2, 3, 5, 8, 13, 21, 34];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for v in &values {
            encoder.write_item(v).await.expect("write_item failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<u32>::new();
    while let Some(v) = decoder.read_item::<u32>().await.expect("read_item failed") {
        decoded.push(v);
    }
    assert_eq!(decoded, values);
}

// ---------------------------------------------------------------------------
// Test 3: Write then read String
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_string_roundtrip() {
    let s = String::from("hello, async oxicode!");

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder.write_item(&s).await.expect("write_item failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got: Option<String> = decoder.read_item().await.expect("read_item failed");
    assert_eq!(got, Some(s));
}

// ---------------------------------------------------------------------------
// Test 4: Write then read Vec<u8>
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_vec_u8_roundtrip() {
    let data: Vec<u8> = (0u8..=255u8).collect();

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder.write_item(&data).await.expect("write_item failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got: Option<Vec<u8>> = decoder.read_item().await.expect("read_item failed");
    assert_eq!(got, Some(data));
}

// ---------------------------------------------------------------------------
// Test 5: Write then read Option<u64> — Some and None variants
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_option_u64_roundtrip() {
    let some_val: Option<u64> = Some(u64::MAX / 2);
    let none_val: Option<u64> = None;

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder
            .write_item(&some_val)
            .await
            .expect("write some failed");
        encoder
            .write_item(&none_val)
            .await
            .expect("write none failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got_some: Option<Option<u64>> = decoder.read_item().await.expect("read some failed");
    let got_none: Option<Option<u64>> = decoder.read_item().await.expect("read none failed");
    assert_eq!(got_some, Some(some_val));
    assert_eq!(got_none, Some(none_val));
}

// ---------------------------------------------------------------------------
// Test 6: Write then read bool values (true, false, true)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_bool_values_roundtrip() {
    let bools = vec![true, false, true, false, false, true];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for b in &bools {
            encoder.write_item(b).await.expect("write_item failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<bool>::new();
    while let Some(v) = decoder.read_item::<bool>().await.expect("read_item failed") {
        decoded.push(v);
    }
    assert_eq!(decoded, bools);
}

// ---------------------------------------------------------------------------
// Test 7: Write then read i64 including negative values
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_i64_including_negative() {
    let values: Vec<i64> = vec![i64::MIN, -1, 0, 1, i64::MAX];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for v in &values {
            encoder.write_item(v).await.expect("write_item failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<i64>::new();
    while let Some(v) = decoder.read_item::<i64>().await.expect("read_item failed") {
        decoded.push(v);
    }
    assert_eq!(decoded, values);
}

// ---------------------------------------------------------------------------
// Test 8: Empty stream — no items written — first read returns None
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_empty_stream_returns_none() {
    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let encoder = AsyncStreamingEncoder::<_>::new(cursor);
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let result: Option<u32> = decoder
        .read_item()
        .await
        .expect("read on empty stream failed");
    assert!(result.is_none());
    assert!(decoder.is_finished());
}

// ---------------------------------------------------------------------------
// Test 9: Write 100 u32 values, read back all 100 via while-let loop
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_100_u32_while_let_loop() {
    let count = 100u32;

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for i in 0..count {
            encoder.write_item(&i).await.expect("write_item failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<u32>::new();
    while let Some(v) = decoder.read_item::<u32>().await.expect("read_item failed") {
        decoded.push(v);
    }

    assert_eq!(decoded.len(), count as usize);
    let expected: Vec<u32> = (0..count).collect();
    assert_eq!(decoded, expected);
}

// ---------------------------------------------------------------------------
// Test 10: Write mixed types sequentially in separate streams, read back
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_mixed_types_separate_streams() {
    // u32 stream
    let mut buf_u32 = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf_u32);
        let mut enc = AsyncStreamingEncoder::new(cursor);
        enc.write_item(&42u32).await.expect("write u32 failed");
        enc.finish().await.expect("finish u32 failed");
    }
    // String stream
    let mut buf_str = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf_str);
        let mut enc = AsyncStreamingEncoder::new(cursor);
        enc.write_item(&String::from("mixed"))
            .await
            .expect("write str failed");
        enc.finish().await.expect("finish str failed");
    }
    // bool stream
    let mut buf_bool = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf_bool);
        let mut enc = AsyncStreamingEncoder::new(cursor);
        enc.write_item(&true).await.expect("write bool failed");
        enc.finish().await.expect("finish bool failed");
    }

    let mut dec_u32 = AsyncStreamingDecoder::new(Cursor::new(buf_u32));
    let mut dec_str = AsyncStreamingDecoder::new(Cursor::new(buf_str));
    let mut dec_bool = AsyncStreamingDecoder::new(Cursor::new(buf_bool));

    assert_eq!(
        dec_u32.read_item::<u32>().await.expect("read u32 failed"),
        Some(42u32)
    );
    assert_eq!(
        dec_str
            .read_item::<String>()
            .await
            .expect("read str failed"),
        Some(String::from("mixed"))
    );
    assert_eq!(
        dec_bool
            .read_item::<bool>()
            .await
            .expect("read bool failed"),
        Some(true)
    );
}

// ---------------------------------------------------------------------------
// Test 11: Write then read large String (1000 chars)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_large_string_1000_chars() {
    let large: String = "x".repeat(1000);

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder
            .write_item(&large)
            .await
            .expect("write large string failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got: Option<String> = decoder.read_item().await.expect("read large string failed");
    assert_eq!(got, Some(large));
}

// ---------------------------------------------------------------------------
// Test 12: Write then read Vec<String>
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_vec_string_roundtrip() {
    let items: Vec<String> = vec![
        String::from("alpha"),
        String::from("beta"),
        String::from("gamma"),
        String::from("delta"),
    ];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder
            .write_item(&items)
            .await
            .expect("write Vec<String> failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got: Option<Vec<String>> = decoder.read_item().await.expect("read Vec<String> failed");
    assert_eq!(got, Some(items));
}

// ---------------------------------------------------------------------------
// Test 13: Async with in-memory Vec<u8> buffer (not file), verify no file I/O
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_in_memory_buffer_no_file() {
    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder.write_item(&0xCAFEu32).await.expect("write failed");
        encoder.write_item(&0xBABEu32).await.expect("write failed");
        encoder.finish().await.expect("finish failed");
    }

    // The buffer is non-empty — data was written to memory only
    assert!(!buf.is_empty());

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let first: Option<u32> = decoder.read_item().await.expect("read first failed");
    let second: Option<u32> = decoder.read_item().await.expect("read second failed");
    assert_eq!(first, Some(0xCAFEu32));
    assert_eq!(second, Some(0xBABEu32));
}

// ---------------------------------------------------------------------------
// Test 14: Write struct, read struct back
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_struct_roundtrip() {
    let points = vec![
        Point2D { x: -10, y: 20 },
        Point2D { x: 0, y: 0 },
        Point2D { x: 100, y: -50 },
    ];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for p in &points {
            encoder.write_item(p).await.expect("write struct failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<Point2D>::new();
    while let Some(p) = decoder
        .read_item::<Point2D>()
        .await
        .expect("read struct failed")
    {
        decoded.push(p);
    }
    assert_eq!(decoded, points);
}

// ---------------------------------------------------------------------------
// Test 15: Write enum values, read back
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_enum_roundtrip() {
    let directions = vec![
        Direction::North,
        Direction::South,
        Direction::East,
        Direction::West,
        Direction::North,
    ];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for d in &directions {
            encoder.write_item(d).await.expect("write enum failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<Direction>::new();
    while let Some(d) = decoder
        .read_item::<Direction>()
        .await
        .expect("read enum failed")
    {
        decoded.push(d);
    }
    assert_eq!(decoded, directions);
}

// ---------------------------------------------------------------------------
// Test 16: Write 0 items, read 0 items (alias for empty stream, different assert focus)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_zero_items_written_zero_read() {
    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let encoder = AsyncStreamingEncoder::<_>::new(cursor);
        encoder.finish().await.expect("finish empty encoder failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut count = 0usize;
    while decoder
        .read_item::<u64>()
        .await
        .expect("read on zero-item stream failed")
        .is_some()
    {
        count += 1;
    }
    assert_eq!(count, 0);
}

// ---------------------------------------------------------------------------
// Test 17: Write 1 item, read 1 item, then next read returns None
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_one_item_then_none() {
    let val: u32 = 99;

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder
            .write_item(&val)
            .await
            .expect("write one item failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let first: Option<u32> = decoder.read_item().await.expect("read first item failed");
    let second: Option<u32> = decoder.read_item().await.expect("read after last failed");
    assert_eq!(first, Some(val));
    assert!(second.is_none());
    assert!(decoder.is_finished());
}

// ---------------------------------------------------------------------------
// Test 18: Write Vec<u8> of 10000 bytes, read back
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_vec_u8_10000_bytes() {
    let data: Vec<u8> = (0u32..10000).map(|i| (i % 256) as u8).collect();

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder
            .write_item(&data)
            .await
            .expect("write 10k bytes failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let got: Option<Vec<u8>> = decoder.read_item().await.expect("read 10k bytes failed");
    assert_eq!(got, Some(data));
}

// ---------------------------------------------------------------------------
// Test 19: Multiple sequential writes then sequential reads (interleaved writes)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_sequential_writes_then_reads() {
    let a: u32 = 111;
    let b: u32 = 222;
    let c: u32 = 333;

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        encoder.write_item(&a).await.expect("write a failed");
        encoder.write_item(&b).await.expect("write b failed");
        encoder.write_item(&c).await.expect("write c failed");
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let ra: Option<u32> = decoder.read_item().await.expect("read a failed");
    let rb: Option<u32> = decoder.read_item().await.expect("read b failed");
    let rc: Option<u32> = decoder.read_item().await.expect("read c failed");
    let rd: Option<u32> = decoder.read_item().await.expect("read eof failed");
    assert_eq!(ra, Some(a));
    assert_eq!(rb, Some(b));
    assert_eq!(rc, Some(c));
    assert!(rd.is_none());
}

// ---------------------------------------------------------------------------
// Test 20: Write then read u128 values (including MIN and MAX)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_u128_min_max_roundtrip() {
    let values: Vec<u128> = vec![u128::MIN, 1, u128::MAX / 3, u128::MAX];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for v in &values {
            encoder.write_item(v).await.expect("write u128 failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<u128>::new();
    while let Some(v) = decoder.read_item::<u128>().await.expect("read u128 failed") {
        decoded.push(v);
    }
    assert_eq!(decoded, values);
}

// ---------------------------------------------------------------------------
// Test 21: Write then read f64 values (use computed values not literals)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_f64_computed_values() {
    // Use computed values to avoid clippy::approx_constant warnings
    let pi = std::f64::consts::PI;
    let e = std::f64::consts::E;
    let sqrt2 = std::f64::consts::SQRT_2;
    let values: Vec<f64> = vec![-pi, -e, -sqrt2, 0.0_f64, sqrt2, e, pi];

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::new(cursor);
        for v in &values {
            encoder.write_item(v).await.expect("write f64 failed");
        }
        encoder.finish().await.expect("finish failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<f64>::new();
    while let Some(v) = decoder.read_item::<f64>().await.expect("read f64 failed") {
        decoded.push(v);
    }
    assert_eq!(decoded.len(), values.len());
    for (a, b) in values.iter().zip(decoded.iter()) {
        assert_eq!(a.to_bits(), b.to_bits(), "f64 bit mismatch: {a} vs {b}");
    }
}

// ---------------------------------------------------------------------------
// Test 22: Write then read with custom config (small chunk size + flush_per_item)
// ---------------------------------------------------------------------------
#[cfg(feature = "async-tokio")]
#[tokio::test]
async fn test_async2_custom_config_small_chunk_flush_per_item() {
    // Small chunk size forces multiple chunks; flush_per_item ensures each item
    // is flushed immediately — exercises the most aggressive flushing path.
    let config = StreamingConfig::new()
        .with_chunk_size(64)
        .with_flush_per_item(true);

    let items: Vec<u32> = (200u32..215u32).collect();

    let mut buf = Vec::<u8>::new();
    {
        let cursor = Cursor::new(&mut buf);
        let mut encoder = AsyncStreamingEncoder::with_config(cursor, config);
        for item in &items {
            encoder
                .write_item(item)
                .await
                .expect("write with config failed");
        }
        encoder.finish().await.expect("finish with config failed");
    }

    let cursor = Cursor::new(buf);
    let mut decoder = AsyncStreamingDecoder::new(cursor);
    let mut decoded = Vec::<u32>::new();
    while let Some(v) = decoder
        .read_item::<u32>()
        .await
        .expect("read with config failed")
    {
        decoded.push(v);
    }

    assert_eq!(decoded, items);
    // Each item was flushed individually, so we expect as many chunks as items
    assert_eq!(
        decoder.progress().chunks_processed,
        items.len() as u64,
        "expected one chunk per item with flush_per_item"
    );
}