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
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
//! Reflection in Rust.
//!
//! [Reflection] is a powerful tool provided within many programming languages
//! that allows for meta-programming: using information _about_ the program to
//! _affect_ the program.
//! In other words, reflection allows us to inspect the program itself, its
//! syntax, and its type information at runtime.
//!
//! This crate adds this missing reflection functionality to Rust.
//! Though it was made with the [Bevy] game engine in mind,
//! it's a general-purpose solution that can be used in any Rust project.
//!
//! At a very high level, this crate allows you to:
//! * Dynamically interact with Rust values
//! * Access type metadata at runtime
//! * Serialize and deserialize (i.e. save and load) data
//!
//! It's important to note that because of missing features in Rust,
//! there are some [limitations] with this crate.
//!
//! # The `Reflect` Trait
//!
//! At the core of [`bevy_reflect`] is the [`Reflect`] trait.
//!
//! One of its primary purposes is to allow all implementors to be passed around
//! as a `dyn Reflect` trait object.
//! This allows any such type to be operated upon completely dynamically (at a small [runtime cost]).
//!
//! Implementing the trait is easily done using the provided [derive macro]:
//!
//! ```
//! # use bevy_reflect::Reflect;
//! #[derive(Reflect)]
//! struct MyStruct {
//!   foo: i32
//! }
//! ```
//!
//! This will automatically generate the implementation of `Reflect` for any struct or enum.
//!
//! It will also generate other very important trait implementations used for reflection:
//! * [`GetTypeRegistration`]
//! * [`Typed`]
//! * [`Struct`], [`TupleStruct`], or [`Enum`] depending on the type
//!
//! ## Requirements
//!
//! We can implement `Reflect` on any type that satisfies _both_ of the following conditions:
//! * The type implements `Any`.
//!   This is true if and only if the type itself has a [`'static` lifetime].
//! * All fields and sub-elements themselves implement `Reflect`
//!   (see the [derive macro documentation] for details on how to ignore certain fields when deriving).
//!
//! Additionally, using the derive macro on enums requires a third condition to be met:
//! * All fields and sub-elements must implement [`FromReflect`]—
//! another important reflection trait discussed in a later section.
//!
//! # The `Reflect` Subtraits
//!
//! Since [`Reflect`] is meant to cover any and every type, this crate also comes with a few
//! more traits to accompany `Reflect` and provide more specific interactions.
//! We refer to these traits as the _reflection subtraits_ since they all have `Reflect` as a supertrait.
//! The current list of reflection subtraits include:
//! * [`Tuple`]
//! * [`Array`]
//! * [`List`]
//! * [`Map`]
//! * [`Struct`]
//! * [`TupleStruct`]
//! * [`Enum`]
//!
//! As mentioned previously, the last three are automatically implemented by the [derive macro].
//!
//! Each of these traits come with their own methods specific to their respective category.
//! For example, we can access our struct's fields by name using the [`Struct::field`] method.
//!
//! ```
//! # use bevy_reflect::{Reflect, Struct};
//! # #[derive(Reflect)]
//! # struct MyStruct {
//! #   foo: i32
//! # }
//! let my_struct: Box<dyn Struct> = Box::new(MyStruct {
//!   foo: 123
//! });
//! let foo: &dyn Reflect = my_struct.field("foo").unwrap();
//! assert_eq!(Some(&123), foo.downcast_ref::<i32>());
//! ```
//!
//! Since most data is passed around as `dyn Reflect`,
//! the `Reflect` trait has methods for going to and from these subtraits.
//!
//! [`Reflect::reflect_ref`], [`Reflect::reflect_mut`], and [`Reflect::reflect_owned`] all return
//! an enum that respectively contains immutable, mutable, and owned access to the type as a subtrait object.
//!
//! For example, we can get out a `dyn Tuple` from our reflected tuple type using one of these methods.
//!
//! ```
//! # use bevy_reflect::{Reflect, ReflectRef};
//! let my_tuple: Box<dyn Reflect> = Box::new((1, 2, 3));
//! let ReflectRef::Tuple(my_tuple) = my_tuple.reflect_ref() else { unreachable!() };
//! assert_eq!(3, my_tuple.field_len());
//! ```
//!
//! And to go back to a general-purpose `dyn Reflect`,
//! we can just use the matching [`Reflect::as_reflect`], [`Reflect::as_reflect_mut`],
//! or [`Reflect::into_reflect`] methods.
//!
//! ## Value Types
//!
//! Types that do not fall under one of the above subtraits,
//! such as for primitives (e.g. `bool`, `usize`, etc.)
//! and simple types (e.g. `String`, `Duration`),
//! are referred to as _value_ types
//! since methods like [`Reflect::reflect_ref`] return a [`ReflectRef::Value`] variant.
//! While most other types contain their own `dyn Reflect` fields and data,
//! these types generally cannot be broken down any further.
//!
//! # Dynamic Types
//!
//! Each subtrait comes with a corresponding _dynamic_ type.
//!
//! The available dynamic types are:
//! * [`DynamicTuple`]
//! * [`DynamicArray`]
//! * [`DynamicList`]
//! * [`DynamicMap`]
//! * [`DynamicStruct`]
//! * [`DynamicTupleStruct`]
//! * [`DynamicEnum`]
//!
//! These dynamic types may contain any arbitrary reflected data.
//!
//! ```
//! # use bevy_reflect::{DynamicStruct, Struct};
//! let mut data = DynamicStruct::default();
//! data.insert("foo", 123_i32);
//! assert_eq!(Some(&123), data.field("foo").unwrap().downcast_ref::<i32>())
//! ```
//!
//! They are most commonly used as "proxies" for other types,
//! where they contain the same data as— and therefore, represent— a concrete type.
//! The [`Reflect::clone_value`] method will return a dynamic type for all non-value types,
//! allowing all types to essentially be "cloned".
//! And since dynamic types themselves implement [`Reflect`],
//! we may pass them around just like any other reflected type.
//!
//! ```
//! # use bevy_reflect::{DynamicStruct, Reflect};
//! # #[derive(Reflect)]
//! # struct MyStruct {
//! #   foo: i32
//! # }
//! let original: Box<dyn Reflect> = Box::new(MyStruct {
//!   foo: 123
//! });
//!
//! // `cloned` will be a `DynamicStruct` representing a `MyStruct`
//! let cloned: Box<dyn Reflect> = original.clone_value();
//! assert!(cloned.represents::<MyStruct>());
//! assert!(cloned.is::<DynamicStruct>());
//! ```
//!
//! ## Patching
//!
//! These dynamic types come in handy when needing to apply multiple changes to another type.
//! This is known as "patching" and is done using the [`Reflect::apply`] method.
//!
//! ```
//! # use bevy_reflect::{DynamicEnum, Reflect};
//! let mut value = Some(123_i32);
//! let patch = DynamicEnum::new(std::any::type_name::<Option<i32>>(), "None", ());
//! value.apply(&patch);
//! assert_eq!(None, value);
//! ```
//!
//! ## `FromReflect`
//!
//! It's important to remember that dynamic types are _not_ the concrete type they may be representing.
//! A common mistake is to treat them like such when trying to cast back to the original type
//! or when trying to make use of a reflected trait which expects the actual type.
//!
//! ```should_panic
//! # use bevy_reflect::{DynamicStruct, Reflect};
//! # #[derive(Reflect)]
//! # struct MyStruct {
//! #   foo: i32
//! # }
//! let original: Box<dyn Reflect> = Box::new(MyStruct {
//!   foo: 123
//! });
//!
//! let cloned: Box<dyn Reflect> = original.clone_value();
//! let value = cloned.take::<MyStruct>().unwrap(); // PANIC!
//! ```
//!
//! To resolve this issue, we'll need to convert the dynamic type to the concrete one.
//! This is where [`FromReflect`] comes in.
//!
//! `FromReflect` is a derivable trait that allows an instance of a type to be generated from a
//! dynamic representation— even partial ones.
//! And since the [`FromReflect::from_reflect`] method takes the data by reference,
//! this can be used to effectively clone data (to an extent).
//!
//! This trait can be derived on any type whose fields and sub-elements also implement `FromReflect`.
//!
//! ```
//! # use bevy_reflect::{Reflect, FromReflect};
//! #[derive(Reflect, FromReflect)]
//! struct MyStruct {
//!   foo: i32
//! }
//! let original: Box<dyn Reflect> = Box::new(MyStruct {
//!   foo: 123
//! });
//!
//! let cloned: Box<dyn Reflect> = original.clone_value();
//! let value = <MyStruct as FromReflect>::from_reflect(&*cloned).unwrap(); // OK!
//! ```
//!
//! With the derive macro, fields can be ignored or given default values for when a field is missing
//! in the passed value.
//! See the [derive macro documentation](derive@crate::FromReflect) for details.
//!
//! All primitives and simple types implement `FromReflect` by relying on their [`Default`] implementation.
//!
//! # Type Registration
//!
//! This crate also comes with a [`TypeRegistry`] that can be used to store and retrieve additional type metadata at runtime,
//! such as helper types and trait implementations.
//!
//! The [derive macro] for [`Reflect`] also generates an implementation of the [`GetTypeRegistration`] trait,
//! which is used by the registry to generate a [`TypeRegistration`] struct for that type.
//! We can then register additional [type data] we want associated with that type.
//!
//! For example, we can register [`ReflectDefault`] on our type so that its `Default` implementation
//! may be used dynamically.
//!
//! ```
//! # use bevy_reflect::{Reflect, TypeRegistry, prelude::ReflectDefault};
//! #[derive(Reflect, Default)]
//! struct MyStruct {
//!   foo: i32
//! }
//! let mut registry = TypeRegistry::empty();
//! registry.register::<MyStruct>();
//! registry.register_type_data::<MyStruct, ReflectDefault>();
//!
//! let registration = registry.get(std::any::TypeId::of::<MyStruct>()).unwrap();
//! let reflect_default = registration.data::<ReflectDefault>().unwrap();
//!
//! let new_value: Box<dyn Reflect> = reflect_default.default();
//! assert!(new_value.is::<MyStruct>());
//! ```
//!
//! Because this operation is so common, the derive macro actually has a shorthand for it.
//! By using the `#[reflect(Trait)]` attribute, the derive macro will automatically register a matching,
//! in-scope `ReflectTrait` type within the `GetTypeRegistration` implementation.
//!
//! ```
//! use bevy_reflect::prelude::{Reflect, ReflectDefault};
//!
//! #[derive(Reflect, Default)]
//! #[reflect(Default)]
//! struct MyStruct {
//!   foo: i32
//! }
//! ```
//!
//! ## Reflecting Traits
//!
//! Type data doesn't have to be tied to a trait, but it's often extremely useful to create trait type data.
//! These allow traits to be used directly on a `dyn Reflect` while utilizing the underlying type's implementation.
//!
//! For any [object-safe] trait, we can easily generate a corresponding `ReflectTrait` type for our trait
//! using the [`#[reflect_trait]`](reflect_trait) macro.
//!
//! ```
//! # use bevy_reflect::{Reflect, reflect_trait, TypeRegistry};
//! #[reflect_trait] // Generates a `ReflectMyTrait` type
//! pub trait MyTrait {}
//! impl<T: Reflect> MyTrait for T {}
//!
//! let mut registry = TypeRegistry::new();
//! registry.register_type_data::<i32, ReflectMyTrait>();
//! ```
//!
//! The generated type data can be used to convert a valid `dyn Reflect` into a `dyn MyTrait`.
//! See the [trait reflection example](https://github.com/bevyengine/bevy/blob/latest/examples/reflection/trait_reflection.rs)
//! for more information and usage details.
//!
//! # Serialization
//!
//! By using reflection, we are also able to get serialization capabilities for free.
//! In fact, using [`bevy_reflect`] can result in faster compile times and reduced code generation over
//! directly deriving the [`serde`] traits.
//!
//! The way it works is by moving the serialization logic into common serializers and deserializers:
//! * [`ReflectSerializer`]
//! * [`TypedReflectSerializer`]
//! * [`UntypedReflectDeserializer`]
//! * [`TypedReflectDeserializer`]
//!
//! All of these structs require a reference to the [registry] so that [type information] can be retrieved,
//! as well as registered type data, such as [`ReflectSerialize`] and [`ReflectDeserialize`].
//!
//! The general entry point are the "untyped" versions of these structs.
//! These will automatically extract the type information and pass them into their respective "typed" version.
//!
//! The output of the `ReflectSerializer` will be a map, where the key is the [type name]
//! and the value is the serialized data.
//! The `TypedReflectSerializer` will simply output the serialized data.
//!
//! The `UntypedReflectDeserializer` can be used to deserialize this map and return a `Box<dyn Reflect>`,
//! where the underlying type will be a dynamic type representing some concrete type (except for value types).
//!
//! Again, it's important to remember that dynamic types may need to be converted to their concrete counterparts
//! in order to be used in certain cases.
//! This can be achieved using [`FromReflect`].
//!
//! ```
//! # use serde::de::DeserializeSeed;
//! # use bevy_reflect::{
//! #     serde::{ReflectSerializer, UntypedReflectDeserializer},
//! #     Reflect, FromReflect, TypeRegistry
//! # };
//! #[derive(Reflect, FromReflect, PartialEq, Debug)]
//! struct MyStruct {
//!   foo: i32
//! }
//!
//! let original_value = MyStruct {
//!   foo: 123
//! };
//!
//! // Register
//! let mut registry = TypeRegistry::new();
//! registry.register::<MyStruct>();
//!
//! // Serialize
//! let reflect_serializer = ReflectSerializer::new(&original_value, &registry);
//! let serialized_value: String = ron::to_string(&reflect_serializer).unwrap();
//!
//! // Deserialize
//! let reflect_deserializer = UntypedReflectDeserializer::new(&registry);
//! let deserialized_value: Box<dyn Reflect> = reflect_deserializer.deserialize(
//!   &mut ron::Deserializer::from_str(&serialized_value).unwrap()
//! ).unwrap();
//!
//! // Convert
//! let converted_value = <MyStruct as FromReflect>::from_reflect(&*deserialized_value).unwrap();
//!
//! assert_eq!(original_value, converted_value);
//! ```
//!
//! # Limitations
//!
//! While this crate offers a lot in terms of adding reflection to Rust,
//! it does come with some limitations that don't make it as featureful as reflection
//! in other programming languages.
//!
//! ## Non-Static Lifetimes
//!
//! One of the most obvious limitations is the `'static` requirement.
//! Rust requires fields to define a lifetime for referenced data,
//! but [`Reflect`] requires all types to have a `'static` lifetime.
//! This makes it impossible to reflect any type with non-static borrowed data.
//!
//! ## Function Reflection
//!
//! Another limitation is the inability to fully reflect functions and methods.
//! Most languages offer some way of calling methods dynamically,
//! but Rust makes this very difficult to do.
//! For non-generic methods, this can be done by registering custom [type data] that
//! contains function pointers.
//! For generic methods, the same can be done but will typically require manual monomorphization
//! (i.e. manually specifying the types the generic method can take).
//!
//! ## Manual Registration
//!
//! Since Rust doesn't provide built-in support for running initialization code before `main`,
//! there is no way for `bevy_reflect` to automatically register types into the [type registry].
//! This means types must manually be registered, including their desired monomorphized
//! representations if generic.
//!
//! # Features
//!
//! ## `bevy`
//!
//! | Default | Dependencies                              |
//! | :-----: | :---------------------------------------: |
//! | ❌      | [`bevy_math`], [`glam`], [`smallvec`] |
//!
//! This feature makes it so that the appropriate reflection traits are implemented on all the types
//! necessary for the [Bevy] game engine.
//! enables the optional dependencies: [`bevy_math`], [`glam`], and [`smallvec`].
//! These dependencies are used by the [Bevy] game engine and must define their reflection implementations
//! within this crate due to Rust's [orphan rule].
//!
//! ## `documentation`
//!
//! | Default | Dependencies                                  |
//! | :-----: | :-------------------------------------------: |
//! | ❌      | [`bevy_reflect_derive/documentation`]         |
//!
//! This feature enables capturing doc comments as strings for items that [derive `Reflect`].
//! Documentation information can then be accessed at runtime on the [`TypeInfo`] of that item.
//!
//! This can be useful for generating documentation for scripting language interop or
//! for displaying tooltips in an editor.
//!
//! [Reflection]: https://en.wikipedia.org/wiki/Reflective_programming
//! [Bevy]: https://bevyengine.org/
//! [limitations]: #limitations
//! [`bevy_reflect`]: crate
//! [runtime cost]: https://doc.rust-lang.org/book/ch17-02-trait-objects.html#trait-objects-perform-dynamic-dispatch
//! [derive macro]: derive@crate::Reflect
//! [`'static` lifetime]: https://doc.rust-lang.org/rust-by-example/scope/lifetime/static_lifetime.html#trait-bound
//! [derive macro documentation]: derive@crate::Reflect
//! [type data]: TypeData
//! [`ReflectDefault`]: std_traits::ReflectDefault
//! [object-safe]: https://doc.rust-lang.org/reference/items/traits.html#object-safety
//! [`serde`]: ::serde
//! [`ReflectSerializer`]: serde::ReflectSerializer
//! [`TypedReflectSerializer`]: serde::TypedReflectSerializer
//! [`UntypedReflectDeserializer`]: serde::UntypedReflectDeserializer
//! [`TypedReflectDeserializer`]: serde::TypedReflectDeserializer
//! [registry]: TypeRegistry
//! [type information]: TypeInfo
//! [type name]: Reflect::type_name
//! [type registry]: TypeRegistry
//! [`bevy_math`]: https://docs.rs/bevy_math/latest/bevy_math/
//! [`glam`]: https://docs.rs/glam/latest/glam/
//! [`smallvec`]: https://docs.rs/smallvec/latest/smallvec/
//! [orphan rule]: https://doc.rust-lang.org/book/ch10-02-traits.html#implementing-a-trait-on-a-type:~:text=But%20we%20can%E2%80%99t,implementation%20to%20use.
//! [`bevy_reflect_derive/documentation`]: bevy_reflect_derive
//! [derive `Reflect`]: derive@crate::Reflect

mod array;
mod fields;
mod from_reflect;
mod list;
mod map;
mod path;
mod reflect;
mod struct_trait;
mod tuple;
mod tuple_struct;
mod type_info;
mod type_registry;
mod type_uuid;
mod type_uuid_impl;
mod impls {
    #[cfg(feature = "glam")]
    mod glam;
    #[cfg(feature = "bevy_math")]
    mod rect;
    #[cfg(feature = "smallvec")]
    mod smallvec;
    mod std;

    #[cfg(feature = "glam")]
    pub use self::glam::*;
    #[cfg(feature = "bevy_math")]
    pub use self::rect::*;
    #[cfg(feature = "smallvec")]
    pub use self::smallvec::*;
    pub use self::std::*;
}

mod enums;
pub mod serde;
pub mod std_traits;
pub mod utility;

pub mod prelude {
    pub use crate::std_traits::*;
    #[doc(hidden)]
    pub use crate::{
        reflect_trait, FromReflect, GetField, GetTupleStructField, Reflect, ReflectDeserialize,
        ReflectSerialize, Struct, TupleStruct,
    };
}

pub use array::*;
pub use enums::*;
pub use fields::*;
pub use from_reflect::*;
pub use impls::*;
pub use list::*;
pub use map::*;
pub use path::*;
pub use reflect::*;
pub use struct_trait::*;
pub use tuple::*;
pub use tuple_struct::*;
pub use type_info::*;
pub use type_registry::*;
pub use type_uuid::*;

pub use bevy_reflect_derive::*;
pub use erased_serde;

#[doc(hidden)]
pub mod __macro_exports {
    use crate::Uuid;

    /// Generates a new UUID from the given UUIDs `a` and `b`,
    /// where the bytes are generated by a bitwise `a ^ b.rotate_right(1)`.
    /// The generated UUID will be a `UUIDv4` (meaning that the bytes should be random, not e.g. derived from the system time).
    #[allow(clippy::unusual_byte_groupings)] // unusual byte grouping is meant to signal the relevant bits
    pub const fn generate_composite_uuid(a: Uuid, b: Uuid) -> Uuid {
        let mut new = [0; 16];
        let mut i = 0;
        while i < new.len() {
            // rotating ensures different uuids for A<B<C>> and B<A<C>> because: A ^ (B ^ C) = B ^ (A ^ C)
            // notice that you have to rotate the second parameter: A.rr ^ (B.rr ^ C) = B.rr ^ (A.rr ^ C)
            // Solution: A ^ (B ^ C.rr).rr != B ^ (A ^ C.rr).rr
            new[i] = a.as_bytes()[i] ^ b.as_bytes()[i].rotate_right(1);

            i += 1;
        }

        // Version: the most significant 4 bits in the 6th byte: 11110000
        new[6] = new[6] & 0b0000_1111 | 0b0100_0000; // set version to v4

        // Variant: the most significant 3 bits in the 8th byte: 11100000
        new[8] = new[8] & 0b000_11111 | 0b100_00000; // set variant to rfc4122

        Uuid::from_bytes(new)
    }
}

#[cfg(test)]
#[allow(clippy::disallowed_types, clippy::approx_constant)]
mod tests {
    #[cfg(feature = "glam")]
    use ::glam::{vec3, Vec3};
    use ::serde::{de::DeserializeSeed, Deserialize, Serialize};
    use bevy_utils::HashMap;
    use ron::{
        ser::{to_string_pretty, PrettyConfig},
        Deserializer,
    };
    use std::any::TypeId;
    use std::fmt::{Debug, Formatter};

    use super::prelude::*;
    use super::*;
    use crate as bevy_reflect;
    use crate::serde::{ReflectSerializer, UntypedReflectDeserializer};

    #[test]
    fn reflect_struct() {
        #[derive(Reflect)]
        struct Foo {
            a: u32,
            b: f32,
            c: Bar,
        }
        #[derive(Reflect)]
        struct Bar {
            x: u32,
        }

        let mut foo = Foo {
            a: 42,
            b: 3.14,
            c: Bar { x: 1 },
        };

        let a = *foo.get_field::<u32>("a").unwrap();
        assert_eq!(a, 42);

        *foo.get_field_mut::<u32>("a").unwrap() += 1;
        assert_eq!(foo.a, 43);

        let bar = foo.get_field::<Bar>("c").unwrap();
        assert_eq!(bar.x, 1);

        // nested retrieval
        let c = foo.field("c").unwrap();
        if let ReflectRef::Struct(value) = c.reflect_ref() {
            assert_eq!(*value.get_field::<u32>("x").unwrap(), 1);
        } else {
            panic!("Expected a struct.");
        }

        // patch Foo with a dynamic struct
        let mut dynamic_struct = DynamicStruct::default();
        dynamic_struct.insert("a", 123u32);
        dynamic_struct.insert("should_be_ignored", 456);

        foo.apply(&dynamic_struct);
        assert_eq!(foo.a, 123);
    }

    #[test]
    fn reflect_map() {
        #[derive(Reflect, Hash)]
        #[reflect(Hash)]
        struct Foo {
            a: u32,
            b: String,
        }

        let key_a = Foo {
            a: 1,
            b: "k1".to_string(),
        };

        let key_b = Foo {
            a: 1,
            b: "k1".to_string(),
        };

        let key_c = Foo {
            a: 3,
            b: "k3".to_string(),
        };

        let mut map = DynamicMap::default();
        map.insert(key_a, 10u32);
        assert_eq!(10, *map.get(&key_b).unwrap().downcast_ref::<u32>().unwrap());
        assert!(map.get(&key_c).is_none());
        *map.get_mut(&key_b).unwrap().downcast_mut::<u32>().unwrap() = 20;
        assert_eq!(20, *map.get(&key_b).unwrap().downcast_ref::<u32>().unwrap());
    }

    #[test]
    #[allow(clippy::disallowed_types)]
    fn reflect_unit_struct() {
        #[derive(Reflect)]
        struct Foo(u32, u64);

        let mut foo = Foo(1, 2);
        assert_eq!(1, *foo.get_field::<u32>(0).unwrap());
        assert_eq!(2, *foo.get_field::<u64>(1).unwrap());

        let mut patch = DynamicTupleStruct::default();
        patch.insert(3u32);
        patch.insert(4u64);
        assert_eq!(3, *patch.field(0).unwrap().downcast_ref::<u32>().unwrap());
        assert_eq!(4, *patch.field(1).unwrap().downcast_ref::<u64>().unwrap());

        foo.apply(&patch);
        assert_eq!(3, foo.0);
        assert_eq!(4, foo.1);

        let mut iter = patch.iter_fields();
        assert_eq!(3, *iter.next().unwrap().downcast_ref::<u32>().unwrap());
        assert_eq!(4, *iter.next().unwrap().downcast_ref::<u64>().unwrap());
    }

    #[test]
    #[should_panic(expected = "the given key does not support hashing")]
    fn reflect_map_no_hash() {
        #[derive(Reflect)]
        struct Foo {
            a: u32,
        }

        let foo = Foo { a: 1 };

        let mut map = DynamicMap::default();
        map.insert(foo, 10u32);
    }

    #[test]
    fn reflect_ignore() {
        #[derive(Reflect)]
        struct Foo {
            a: u32,
            #[reflect(ignore)]
            _b: u32,
        }

        let foo = Foo { a: 1, _b: 2 };

        let values: Vec<u32> = foo
            .iter_fields()
            .map(|value| *value.downcast_ref::<u32>().unwrap())
            .collect();
        assert_eq!(values, vec![1]);
    }

    #[test]
    fn should_call_from_reflect_dynamically() {
        #[derive(Reflect, FromReflect)]
        #[reflect(FromReflect)]
        struct MyStruct {
            foo: usize,
        }

        // Register
        let mut registry = TypeRegistry::default();
        registry.register::<MyStruct>();

        // Get type data
        let type_id = TypeId::of::<MyStruct>();
        let rfr = registry
            .get_type_data::<ReflectFromReflect>(type_id)
            .expect("the FromReflect trait should be registered");

        // Call from_reflect
        let mut dynamic_struct = DynamicStruct::default();
        dynamic_struct.insert("foo", 123usize);
        let reflected = rfr
            .from_reflect(&dynamic_struct)
            .expect("the type should be properly reflected");

        // Assert
        let expected = MyStruct { foo: 123 };
        assert!(expected
            .reflect_partial_eq(reflected.as_ref())
            .unwrap_or_default());
        let not_expected = MyStruct { foo: 321 };
        assert!(!not_expected
            .reflect_partial_eq(reflected.as_ref())
            .unwrap_or_default());
    }

    #[test]
    fn from_reflect_should_use_default_field_attributes() {
        #[derive(Reflect, FromReflect, Eq, PartialEq, Debug)]
        struct MyStruct {
            // Use `Default::default()`
            // Note that this isn't an ignored field
            #[reflect(default)]
            foo: String,

            // Use `get_bar_default()`
            #[reflect(default = "get_bar_default")]
            #[reflect(ignore)]
            bar: usize,
        }

        fn get_bar_default() -> usize {
            123
        }

        let expected = MyStruct {
            foo: String::default(),
            bar: 123,
        };

        let dyn_struct = DynamicStruct::default();
        let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);

        assert_eq!(Some(expected), my_struct);
    }

    #[test]
    fn from_reflect_should_use_default_container_attribute() {
        #[derive(Reflect, FromReflect, Eq, PartialEq, Debug)]
        #[reflect(Default)]
        struct MyStruct {
            foo: String,
            #[reflect(ignore)]
            bar: usize,
        }

        impl Default for MyStruct {
            fn default() -> Self {
                Self {
                    foo: String::from("Hello"),
                    bar: 123,
                }
            }
        }

        let expected = MyStruct {
            foo: String::from("Hello"),
            bar: 123,
        };

        let dyn_struct = DynamicStruct::default();
        let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);

        assert_eq!(Some(expected), my_struct);
    }

    #[test]
    fn reflect_complex_patch() {
        #[derive(Reflect, Eq, PartialEq, Debug, FromReflect)]
        #[reflect(PartialEq)]
        struct Foo {
            a: u32,
            #[reflect(ignore)]
            _b: u32,
            c: Vec<isize>,
            d: HashMap<usize, i8>,
            e: Bar,
            f: (i32, Vec<isize>, Bar),
            g: Vec<(Baz, HashMap<usize, Bar>)>,
            h: [u32; 2],
        }

        #[derive(Reflect, Eq, PartialEq, Clone, Debug, FromReflect)]
        #[reflect(PartialEq)]
        struct Bar {
            x: u32,
        }

        #[derive(Reflect, Eq, PartialEq, Debug, FromReflect)]
        struct Baz(String);

        let mut hash_map = HashMap::default();
        hash_map.insert(1, 1);
        hash_map.insert(2, 2);

        let mut hash_map_baz = HashMap::default();
        hash_map_baz.insert(1, Bar { x: 0 });

        let mut foo = Foo {
            a: 1,
            _b: 1,
            c: vec![1, 2],
            d: hash_map,
            e: Bar { x: 1 },
            f: (1, vec![1, 2], Bar { x: 1 }),
            g: vec![(Baz("string".to_string()), hash_map_baz)],
            h: [2; 2],
        };

        let mut foo_patch = DynamicStruct::default();
        foo_patch.insert("a", 2u32);
        foo_patch.insert("b", 2u32); // this should be ignored

        let mut list = DynamicList::default();
        list.push(3isize);
        list.push(4isize);
        list.push(5isize);
        foo_patch.insert("c", list.clone_dynamic());

        let mut map = DynamicMap::default();
        map.insert(2usize, 3i8);
        map.insert(3usize, 4i8);
        foo_patch.insert("d", map);

        let mut bar_patch = DynamicStruct::default();
        bar_patch.insert("x", 2u32);
        foo_patch.insert("e", bar_patch.clone_dynamic());

        let mut tuple = DynamicTuple::default();
        tuple.insert(2i32);
        tuple.insert(list);
        tuple.insert(bar_patch);
        foo_patch.insert("f", tuple);

        let mut composite = DynamicList::default();
        composite.push({
            let mut tuple = DynamicTuple::default();
            tuple.insert({
                let mut tuple_struct = DynamicTupleStruct::default();
                tuple_struct.insert("new_string".to_string());
                tuple_struct
            });
            tuple.insert({
                let mut map = DynamicMap::default();
                map.insert(1usize, {
                    let mut struct_ = DynamicStruct::default();
                    struct_.insert("x", 7u32);
                    struct_
                });
                map
            });
            tuple
        });
        foo_patch.insert("g", composite);

        let array = DynamicArray::from_vec(vec![2u32, 2u32]);
        foo_patch.insert("h", array);

        foo.apply(&foo_patch);

        let mut hash_map = HashMap::default();
        hash_map.insert(1, 1);
        hash_map.insert(2, 3);
        hash_map.insert(3, 4);

        let mut hash_map_baz = HashMap::default();
        hash_map_baz.insert(1, Bar { x: 7 });

        let expected_foo = Foo {
            a: 2,
            _b: 1,
            c: vec![3, 4, 5],
            d: hash_map,
            e: Bar { x: 2 },
            f: (2, vec![3, 4, 5], Bar { x: 2 }),
            g: vec![(Baz("new_string".to_string()), hash_map_baz.clone())],
            h: [2; 2],
        };

        assert_eq!(foo, expected_foo);

        let new_foo = Foo::from_reflect(&foo_patch)
            .expect("error while creating a concrete type from a dynamic type");

        let mut hash_map = HashMap::default();
        hash_map.insert(2, 3);
        hash_map.insert(3, 4);

        let expected_new_foo = Foo {
            a: 2,
            _b: 0,
            c: vec![3, 4, 5],
            d: hash_map,
            e: Bar { x: 2 },
            f: (2, vec![3, 4, 5], Bar { x: 2 }),
            g: vec![(Baz("new_string".to_string()), hash_map_baz)],
            h: [2; 2],
        };

        assert_eq!(new_foo, expected_new_foo);
    }

    #[test]
    fn reflect_serialize() {
        #[derive(Reflect)]
        struct Foo {
            a: u32,
            #[reflect(ignore)]
            _b: u32,
            c: Vec<isize>,
            d: HashMap<usize, i8>,
            e: Bar,
            f: String,
            g: (i32, Vec<isize>, Bar),
            h: [u32; 2],
        }

        #[derive(Reflect, Serialize, Deserialize)]
        #[reflect(Serialize, Deserialize)]
        struct Bar {
            x: u32,
        }

        let mut hash_map = HashMap::default();
        hash_map.insert(1, 1);
        hash_map.insert(2, 2);
        let foo = Foo {
            a: 1,
            _b: 1,
            c: vec![1, 2],
            d: hash_map,
            e: Bar { x: 1 },
            f: "hi".to_string(),
            g: (1, vec![1, 2], Bar { x: 1 }),
            h: [2; 2],
        };

        let mut registry = TypeRegistry::default();
        registry.register::<u32>();
        registry.register::<i8>();
        registry.register::<i32>();
        registry.register::<usize>();
        registry.register::<isize>();
        registry.register::<Foo>();
        registry.register::<Bar>();
        registry.register::<String>();
        registry.register::<Vec<isize>>();
        registry.register::<HashMap<usize, i8>>();
        registry.register::<(i32, Vec<isize>, Bar)>();
        registry.register::<[u32; 2]>();

        let serializer = ReflectSerializer::new(&foo, &registry);
        let serialized = to_string_pretty(&serializer, PrettyConfig::default()).unwrap();

        let mut deserializer = Deserializer::from_str(&serialized).unwrap();
        let reflect_deserializer = UntypedReflectDeserializer::new(&registry);
        let value = reflect_deserializer.deserialize(&mut deserializer).unwrap();
        let dynamic_struct = value.take::<DynamicStruct>().unwrap();

        assert!(foo.reflect_partial_eq(&dynamic_struct).unwrap());
    }

    #[test]
    fn reflect_downcast() {
        #[derive(Reflect, Clone, Debug, PartialEq)]
        struct Bar {
            y: u8,
        }

        #[derive(Reflect, Clone, Debug, PartialEq)]
        struct Foo {
            x: i32,
            s: String,
            b: Bar,
            u: usize,
            t: ([f32; 3], String),
        }

        let foo = Foo {
            x: 123,
            s: "String".to_string(),
            b: Bar { y: 255 },
            u: 1111111111111,
            t: ([3.0, 2.0, 1.0], "Tuple String".to_string()),
        };

        let foo2: Box<dyn Reflect> = Box::new(foo.clone());

        assert_eq!(foo, *foo2.downcast::<Foo>().unwrap());
    }

    #[test]
    fn should_drain_fields() {
        let array_value: Box<dyn Array> = Box::new([123_i32, 321_i32]);
        let fields = array_value.drain();
        assert!(fields[0].reflect_partial_eq(&123_i32).unwrap_or_default());
        assert!(fields[1].reflect_partial_eq(&321_i32).unwrap_or_default());

        let list_value: Box<dyn List> = Box::new(vec![123_i32, 321_i32]);
        let fields = list_value.drain();
        assert!(fields[0].reflect_partial_eq(&123_i32).unwrap_or_default());
        assert!(fields[1].reflect_partial_eq(&321_i32).unwrap_or_default());

        let tuple_value: Box<dyn Tuple> = Box::new((123_i32, 321_i32));
        let fields = tuple_value.drain();
        assert!(fields[0].reflect_partial_eq(&123_i32).unwrap_or_default());
        assert!(fields[1].reflect_partial_eq(&321_i32).unwrap_or_default());

        let map_value: Box<dyn Map> = Box::new(HashMap::from([(123_i32, 321_i32)]));
        let fields = map_value.drain();
        assert!(fields[0].0.reflect_partial_eq(&123_i32).unwrap_or_default());
        assert!(fields[0].1.reflect_partial_eq(&321_i32).unwrap_or_default());
    }

    #[test]
    fn reflect_take() {
        #[derive(Reflect, Debug, PartialEq)]
        #[reflect(PartialEq)]
        struct Bar {
            x: u32,
        }

        let x: Box<dyn Reflect> = Box::new(Bar { x: 2 });
        let y = x.take::<Bar>().unwrap();
        assert_eq!(y, Bar { x: 2 });
    }

    #[test]
    fn dynamic_names() {
        let list = Vec::<usize>::new();
        let dyn_list = list.clone_dynamic();
        assert_eq!(dyn_list.type_name(), std::any::type_name::<Vec<usize>>());

        let array = [b'0'; 4];
        let dyn_array = array.clone_dynamic();
        assert_eq!(dyn_array.type_name(), std::any::type_name::<[u8; 4]>());

        let map = HashMap::<usize, String>::default();
        let dyn_map = map.clone_dynamic();
        assert_eq!(
            dyn_map.type_name(),
            std::any::type_name::<HashMap<usize, String>>()
        );

        let tuple = (0usize, "1".to_string(), 2.0f32);
        let mut dyn_tuple = tuple.clone_dynamic();
        dyn_tuple.insert::<usize>(3);
        assert_eq!(
            dyn_tuple.type_name(),
            std::any::type_name::<(usize, String, f32, usize)>()
        );

        #[derive(Reflect)]
        struct TestStruct {
            a: usize,
        }
        let struct_ = TestStruct { a: 0 };
        let dyn_struct = struct_.clone_dynamic();
        assert_eq!(dyn_struct.type_name(), std::any::type_name::<TestStruct>());

        #[derive(Reflect)]
        struct TestTupleStruct(usize);
        let tuple_struct = TestTupleStruct(0);
        let dyn_tuple_struct = tuple_struct.clone_dynamic();
        assert_eq!(
            dyn_tuple_struct.type_name(),
            std::any::type_name::<TestTupleStruct>()
        );
    }

    #[test]
    fn reflect_type_info() {
        // TypeInfo
        let info = i32::type_info();
        assert_eq!(std::any::type_name::<i32>(), info.type_name());
        assert_eq!(std::any::TypeId::of::<i32>(), info.type_id());

        // TypeInfo (unsized)
        assert_eq!(
            std::any::TypeId::of::<dyn Reflect>(),
            <dyn Reflect as Typed>::type_info().type_id()
        );

        // TypeInfo (instance)
        let value: &dyn Reflect = &123_i32;
        let info = value.get_type_info();
        assert!(info.is::<i32>());

        // Struct
        #[derive(Reflect)]
        struct MyStruct {
            foo: i32,
            bar: usize,
        }

        let info = MyStruct::type_info();
        if let TypeInfo::Struct(info) = info {
            assert!(info.is::<MyStruct>());
            assert_eq!(std::any::type_name::<MyStruct>(), info.type_name());
            assert_eq!(
                std::any::type_name::<i32>(),
                info.field("foo").unwrap().type_name()
            );
            assert_eq!(
                std::any::TypeId::of::<i32>(),
                info.field("foo").unwrap().type_id()
            );
            assert!(info.field("foo").unwrap().is::<i32>());
            assert_eq!("foo", info.field("foo").unwrap().name());
            assert_eq!(
                std::any::type_name::<usize>(),
                info.field_at(1).unwrap().type_name()
            );
        } else {
            panic!("Expected `TypeInfo::Struct`");
        }

        let value: &dyn Reflect = &MyStruct { foo: 123, bar: 321 };
        let info = value.get_type_info();
        assert!(info.is::<MyStruct>());

        // Struct (generic)
        #[derive(Reflect)]
        struct MyGenericStruct<T: Reflect> {
            foo: T,
            bar: usize,
        }

        let info = <MyGenericStruct<i32>>::type_info();
        if let TypeInfo::Struct(info) = info {
            assert!(info.is::<MyGenericStruct<i32>>());
            assert_eq!(
                std::any::type_name::<MyGenericStruct<i32>>(),
                info.type_name()
            );
            assert_eq!(
                std::any::type_name::<i32>(),
                info.field("foo").unwrap().type_name()
            );
            assert_eq!("foo", info.field("foo").unwrap().name());
            assert_eq!(
                std::any::type_name::<usize>(),
                info.field_at(1).unwrap().type_name()
            );
        } else {
            panic!("Expected `TypeInfo::Struct`");
        }

        let value: &dyn Reflect = &MyGenericStruct {
            foo: String::from("Hello!"),
            bar: 321,
        };
        let info = value.get_type_info();
        assert!(info.is::<MyGenericStruct<String>>());

        // Tuple Struct
        #[derive(Reflect)]
        struct MyTupleStruct(usize, i32, MyStruct);

        let info = MyTupleStruct::type_info();
        if let TypeInfo::TupleStruct(info) = info {
            assert!(info.is::<MyTupleStruct>());
            assert_eq!(std::any::type_name::<MyTupleStruct>(), info.type_name());
            assert_eq!(
                std::any::type_name::<i32>(),
                info.field_at(1).unwrap().type_name()
            );
            assert!(info.field_at(1).unwrap().is::<i32>());
        } else {
            panic!("Expected `TypeInfo::TupleStruct`");
        }

        // Tuple
        type MyTuple = (u32, f32, String);

        let info = MyTuple::type_info();
        if let TypeInfo::Tuple(info) = info {
            assert!(info.is::<MyTuple>());
            assert_eq!(std::any::type_name::<MyTuple>(), info.type_name());
            assert_eq!(
                std::any::type_name::<f32>(),
                info.field_at(1).unwrap().type_name()
            );
        } else {
            panic!("Expected `TypeInfo::Tuple`");
        }

        let value: &dyn Reflect = &(123_u32, 1.23_f32, String::from("Hello!"));
        let info = value.get_type_info();
        assert!(info.is::<MyTuple>());

        // List
        type MyList = Vec<usize>;

        let info = MyList::type_info();
        if let TypeInfo::List(info) = info {
            assert!(info.is::<MyList>());
            assert!(info.item_is::<usize>());
            assert_eq!(std::any::type_name::<MyList>(), info.type_name());
            assert_eq!(std::any::type_name::<usize>(), info.item_type_name());
        } else {
            panic!("Expected `TypeInfo::List`");
        }

        let value: &dyn Reflect = &vec![123_usize];
        let info = value.get_type_info();
        assert!(info.is::<MyList>());

        // List (SmallVec)
        #[cfg(feature = "smallvec")]
        {
            type MySmallVec = smallvec::SmallVec<[String; 2]>;

            let info = MySmallVec::type_info();
            if let TypeInfo::List(info) = info {
                assert!(info.is::<MySmallVec>());
                assert!(info.item_is::<String>());
                assert_eq!(std::any::type_name::<MySmallVec>(), info.type_name());
                assert_eq!(std::any::type_name::<String>(), info.item_type_name());
            } else {
                panic!("Expected `TypeInfo::List`");
            }

            let value: MySmallVec = smallvec::smallvec![String::default(); 2];
            let value: &dyn Reflect = &value;
            let info = value.get_type_info();
            assert!(info.is::<MySmallVec>());
        }

        // Array
        type MyArray = [usize; 3];

        let info = MyArray::type_info();
        if let TypeInfo::Array(info) = info {
            assert!(info.is::<MyArray>());
            assert!(info.item_is::<usize>());
            assert_eq!(std::any::type_name::<MyArray>(), info.type_name());
            assert_eq!(std::any::type_name::<usize>(), info.item_type_name());
            assert_eq!(3, info.capacity());
        } else {
            panic!("Expected `TypeInfo::Array`");
        }

        let value: &dyn Reflect = &[1usize, 2usize, 3usize];
        let info = value.get_type_info();
        assert!(info.is::<MyArray>());

        // Map
        type MyMap = HashMap<usize, f32>;

        let info = MyMap::type_info();
        if let TypeInfo::Map(info) = info {
            assert!(info.is::<MyMap>());
            assert!(info.key_is::<usize>());
            assert!(info.value_is::<f32>());
            assert_eq!(std::any::type_name::<MyMap>(), info.type_name());
            assert_eq!(std::any::type_name::<usize>(), info.key_type_name());
            assert_eq!(std::any::type_name::<f32>(), info.value_type_name());
        } else {
            panic!("Expected `TypeInfo::Map`");
        }

        let value: &dyn Reflect = &MyMap::new();
        let info = value.get_type_info();
        assert!(info.is::<MyMap>());

        // Value
        type MyValue = String;

        let info = MyValue::type_info();
        if let TypeInfo::Value(info) = info {
            assert!(info.is::<MyValue>());
            assert_eq!(std::any::type_name::<MyValue>(), info.type_name());
        } else {
            panic!("Expected `TypeInfo::Value`");
        }

        let value: &dyn Reflect = &String::from("Hello!");
        let info = value.get_type_info();
        assert!(info.is::<MyValue>());

        // Dynamic
        type MyDynamic = DynamicList;

        let info = MyDynamic::type_info();
        if let TypeInfo::Dynamic(info) = info {
            assert!(info.is::<MyDynamic>());
            assert_eq!(std::any::type_name::<MyDynamic>(), info.type_name());
        } else {
            panic!("Expected `TypeInfo::Dynamic`");
        }

        let value: &dyn Reflect = &DynamicList::default();
        let info = value.get_type_info();
        assert!(info.is::<MyDynamic>());
    }

    #[cfg(feature = "documentation")]
    mod docstrings {
        use super::*;

        #[test]
        fn should_not_contain_docs() {
            // Regular comments do not count as doc comments,
            // and are therefore not reflected.
            #[derive(Reflect)]
            struct SomeStruct;

            let info = <SomeStruct as Typed>::type_info();
            assert_eq!(None, info.docs());

            /*
             * Block comments do not count as doc comments,
             * and are therefore not reflected.
             */
            #[derive(Reflect)]
            struct SomeOtherStruct;

            let info = <SomeOtherStruct as Typed>::type_info();
            assert_eq!(None, info.docs());
        }

        #[test]
        fn should_contain_docs() {
            /// Some struct.
            ///
            /// # Example
            ///
            /// ```ignore
            /// let some_struct = SomeStruct;
            /// ```
            #[derive(Reflect)]
            struct SomeStruct;

            let info = <SomeStruct as Typed>::type_info();
            assert_eq!(
                Some(" Some struct.\n\n # Example\n\n ```ignore\n let some_struct = SomeStruct;\n ```"),
                info.docs()
            );

            #[doc = "The compiler automatically converts `///`-style comments into `#[doc]` attributes."]
            #[doc = "Of course, you _could_ use the attribute directly if you wanted to."]
            #[doc = "Both will be reflected."]
            #[derive(Reflect)]
            struct SomeOtherStruct;

            let info = <SomeOtherStruct as Typed>::type_info();
            assert_eq!(
                Some("The compiler automatically converts `///`-style comments into `#[doc]` attributes.\nOf course, you _could_ use the attribute directly if you wanted to.\nBoth will be reflected."),
                info.docs()
            );

            /// Some tuple struct.
            #[derive(Reflect)]
            struct SomeTupleStruct(usize);

            let info = <SomeTupleStruct as Typed>::type_info();
            assert_eq!(Some(" Some tuple struct."), info.docs());

            /// Some enum.
            #[derive(Reflect)]
            enum SomeEnum {
                Foo,
            }

            let info = <SomeEnum as Typed>::type_info();
            assert_eq!(Some(" Some enum."), info.docs());

            #[derive(Clone)]
            struct SomePrimitive;
            impl_reflect_value!(
                /// Some primitive for which we have attributed custom documentation.
                SomePrimitive
            );

            let info = <SomePrimitive as Typed>::type_info();
            assert_eq!(
                Some(" Some primitive for which we have attributed custom documentation."),
                info.docs()
            );
        }

        #[test]
        fn fields_should_contain_docs() {
            #[derive(Reflect)]
            struct SomeStruct {
                /// The name
                name: String,
                /// The index
                index: usize,
                // Not documented...
                data: Vec<i32>,
            }

            let info = <SomeStruct as Typed>::type_info();
            if let TypeInfo::Struct(info) = info {
                let mut fields = info.iter();
                assert_eq!(Some(" The name"), fields.next().unwrap().docs());
                assert_eq!(Some(" The index"), fields.next().unwrap().docs());
                assert_eq!(None, fields.next().unwrap().docs());
            } else {
                panic!("expected struct info");
            }
        }

        #[test]
        fn variants_should_contain_docs() {
            #[derive(Reflect)]
            enum SomeEnum {
                // Not documented...
                Nothing,
                /// Option A
                A(
                    /// Index
                    usize,
                ),
                /// Option B
                B {
                    /// Name
                    name: String,
                },
            }

            let info = <SomeEnum as Typed>::type_info();
            if let TypeInfo::Enum(info) = info {
                let mut variants = info.iter();
                assert_eq!(None, variants.next().unwrap().docs());

                let variant = variants.next().unwrap();
                assert_eq!(Some(" Option A"), variant.docs());
                if let VariantInfo::Tuple(variant) = variant {
                    let field = variant.field_at(0).unwrap();
                    assert_eq!(Some(" Index"), field.docs());
                } else {
                    panic!("expected tuple variant")
                }

                let variant = variants.next().unwrap();
                assert_eq!(Some(" Option B"), variant.docs());
                if let VariantInfo::Struct(variant) = variant {
                    let field = variant.field_at(0).unwrap();
                    assert_eq!(Some(" Name"), field.docs());
                } else {
                    panic!("expected struct variant")
                }
            } else {
                panic!("expected enum info");
            }
        }
    }

    #[test]
    fn into_reflect() {
        trait TestTrait: Reflect {}

        #[derive(Reflect)]
        struct TestStruct;

        impl TestTrait for TestStruct {}

        let trait_object: Box<dyn TestTrait> = Box::new(TestStruct);

        // Should compile:
        let _ = trait_object.into_reflect();
    }

    #[test]
    fn as_reflect() {
        trait TestTrait: Reflect {}

        #[derive(Reflect)]
        struct TestStruct;

        impl TestTrait for TestStruct {}

        let trait_object: Box<dyn TestTrait> = Box::new(TestStruct);

        // Should compile:
        let _ = trait_object.as_reflect();
    }

    #[test]
    fn should_reflect_debug() {
        #[derive(Reflect)]
        struct Test {
            value: usize,
            list: Vec<String>,
            array: [f32; 3],
            map: HashMap<i32, f32>,
            a_struct: SomeStruct,
            a_tuple_struct: SomeTupleStruct,
            enum_unit: SomeEnum,
            enum_tuple: SomeEnum,
            enum_struct: SomeEnum,
            custom: CustomDebug,
            #[reflect(ignore)]
            #[allow(dead_code)]
            ignored: isize,
        }

        #[derive(Reflect)]
        struct SomeStruct {
            foo: String,
        }

        #[derive(Reflect)]
        enum SomeEnum {
            A,
            B(usize),
            C { value: i32 },
        }

        #[derive(Reflect)]
        struct SomeTupleStruct(String);

        #[derive(Reflect)]
        #[reflect(Debug)]
        struct CustomDebug;
        impl Debug for CustomDebug {
            fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
                f.write_str("Cool debug!")
            }
        }

        let mut map = HashMap::new();
        map.insert(123, 1.23);

        let test = Test {
            value: 123,
            list: vec![String::from("A"), String::from("B"), String::from("C")],
            array: [1.0, 2.0, 3.0],
            map,
            a_struct: SomeStruct {
                foo: String::from("A Struct!"),
            },
            a_tuple_struct: SomeTupleStruct(String::from("A Tuple Struct!")),
            enum_unit: SomeEnum::A,
            enum_tuple: SomeEnum::B(123),
            enum_struct: SomeEnum::C { value: 321 },
            custom: CustomDebug,
            ignored: 321,
        };

        let reflected: &dyn Reflect = &test;
        let expected = r#"
bevy_reflect::tests::should_reflect_debug::Test {
    value: 123,
    list: [
        "A",
        "B",
        "C",
    ],
    array: [
        1.0,
        2.0,
        3.0,
    ],
    map: {
        123: 1.23,
    },
    a_struct: bevy_reflect::tests::should_reflect_debug::SomeStruct {
        foo: "A Struct!",
    },
    a_tuple_struct: bevy_reflect::tests::should_reflect_debug::SomeTupleStruct(
        "A Tuple Struct!",
    ),
    enum_unit: A,
    enum_tuple: B(
        123,
    ),
    enum_struct: C {
        value: 321,
    },
    custom: Cool debug!,
}"#;

        assert_eq!(expected, format!("\n{reflected:#?}"));
    }

    #[test]
    fn multiple_reflect_lists() {
        #[derive(Hash, PartialEq, Reflect)]
        #[reflect(Debug, Hash)]
        #[reflect(PartialEq)]
        struct Foo(i32);

        impl Debug for Foo {
            fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
                write!(f, "Foo")
            }
        }

        let foo = Foo(123);
        let foo: &dyn Reflect = &foo;

        assert!(foo.reflect_hash().is_some());
        assert_eq!(Some(true), foo.reflect_partial_eq(foo));
        assert_eq!("Foo".to_string(), format!("{foo:?}"));
    }

    #[test]
    fn multiple_reflect_value_lists() {
        #[derive(Clone, Hash, PartialEq, Reflect)]
        #[reflect_value(Debug, Hash)]
        #[reflect_value(PartialEq)]
        struct Foo(i32);

        impl Debug for Foo {
            fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
                write!(f, "Foo")
            }
        }

        let foo = Foo(123);
        let foo: &dyn Reflect = &foo;

        assert!(foo.reflect_hash().is_some());
        assert_eq!(Some(true), foo.reflect_partial_eq(foo));
        assert_eq!("Foo".to_string(), format!("{foo:?}"));
    }

    #[cfg(feature = "glam")]
    mod glam {
        use super::*;

        #[test]
        fn vec3_serialization() {
            let v = vec3(12.0, 3.0, -6.9);

            let mut registry = TypeRegistry::default();
            registry.register::<f32>();
            registry.register::<Vec3>();

            let ser = ReflectSerializer::new(&v, &registry);

            let config = PrettyConfig::default()
                .new_line(String::from("\n"))
                .indentor(String::from("    "));
            let output = to_string_pretty(&ser, config).unwrap();
            let expected = r#"
{
    "glam::f32::vec3::Vec3": (
        x: 12.0,
        y: 3.0,
        z: -6.9,
    ),
}"#;

            assert_eq!(expected, format!("\n{output}"));
        }

        #[test]
        fn vec3_deserialization() {
            let data = r#"
{
    "glam::f32::vec3::Vec3": (
        x: 12.0,
        y: 3.0,
        z: -6.9,
    ),
}"#;

            let mut registry = TypeRegistry::default();
            registry.add_registration(Vec3::get_type_registration());
            registry.add_registration(f32::get_type_registration());

            let de = UntypedReflectDeserializer::new(&registry);

            let mut deserializer =
                ron::de::Deserializer::from_str(data).expect("Failed to acquire deserializer");

            let dynamic_struct = de
                .deserialize(&mut deserializer)
                .expect("Failed to deserialize");

            let mut result = Vec3::default();

            result.apply(&*dynamic_struct);

            assert_eq!(result, vec3(12.0, 3.0, -6.9));
        }

        #[test]
        fn vec3_field_access() {
            let mut v = vec3(1.0, 2.0, 3.0);

            assert_eq!(*v.get_field::<f32>("x").unwrap(), 1.0);

            *v.get_field_mut::<f32>("y").unwrap() = 6.0;

            assert_eq!(v.y, 6.0);
        }

        #[test]
        fn vec3_path_access() {
            let mut v = vec3(1.0, 2.0, 3.0);

            assert_eq!(
                *v.reflect_path("x").unwrap().downcast_ref::<f32>().unwrap(),
                1.0
            );

            *v.reflect_path_mut("y")
                .unwrap()
                .downcast_mut::<f32>()
                .unwrap() = 6.0;

            assert_eq!(v.y, 6.0);
        }

        #[test]
        fn vec3_apply_dynamic() {
            let mut v = vec3(3.0, 3.0, 3.0);

            let mut d = DynamicStruct::default();
            d.insert("x", 4.0f32);
            d.insert("y", 2.0f32);
            d.insert("z", 1.0f32);

            v.apply(&d);

            assert_eq!(v, vec3(4.0, 2.0, 1.0));
        }
    }
}