    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

    //! # Cargo test support.
    //!
    //! See <https://rust-lang.github.io/cargo/contrib/> for a guide on writing tests.
    //!
    //! WARNING: You might not want to use this outside of Cargo.
    //!
    //! * This is designed for testing Cargo itself. Use at your own risk.
    //! * No guarantee on any stability across versions.
    //! * No feature request would be accepted unless proved useful for testing Cargo.

    #![allow(clippy::disallowed_methods)]
    #![allow(clippy::print_stderr)]
    #![allow(clippy::print_stdout)]

    use std::env;
    use std::ffi::OsStr;
    use std::fmt::Write;
    use std::fs;
    use std::os;
    use std::path::{Path, PathBuf};
    use std::process::{Command, Output};
    use std::sync::OnceLock;
    use std::thread::JoinHandle;
    use std::time::{self, Duration};

    use anyhow::{bail, Result};
    use cargo_util::{is_ci, ProcessBuilder, ProcessError};
    use url::Url;

    use self::paths::CargoPathExt;

    #[macro_export]
    macro_rules! t {
        ($e:expr) => {
            match $e {
                Ok(e) => e,
                Err(e) => $crate::panic_error(&format!("failed running {}", stringify!($e)), e),
            }
        };
    }

    pub use snapbox::file;
    pub use snapbox::path::current_dir;
    pub use snapbox::str;

    #[track_caller]
    pub fn panic_error(what: &str, err: impl Into<anyhow::Error>) -> ! {
        let err = err.into();
        pe(what, err);
        #[track_caller]
        fn pe(what: &str, err: anyhow::Error) -> ! {
            let mut result = format!("{}\nerror: {}", what, err);
            for cause in err.chain().skip(1) {
                let _ = writeln!(result, "\nCaused by:");
                let _ = write!(result, "{}", cause);
            }
            panic!("\n{}", result);
        }
    }

    pub use cargo_test_macro::cargo_test;

    pub mod compare;
    pub mod containers;
    pub mod cross_compile;
    mod diff;
    pub mod git;
    pub mod install;
    pub mod paths;
    pub mod publish;
    pub mod registry;
    pub mod tools;

    pub mod prelude {
        pub use crate::ArgLine;
        pub use crate::CargoCommand;
        pub use crate::ChannelChanger;
        pub use crate::TestEnv;
    }

    /*
     *
     * ===== Builders =====
     *
     */

    #[derive(PartialEq, Clone)]
    struct FileBuilder {
        path: PathBuf,
        body: String,
        executable: bool,
    }

    impl FileBuilder {
        pub fn new(path: PathBuf, body: &str, executable: bool) -> FileBuilder {
            FileBuilder {
                path,
                body: body.to_string(),
                executable: executable,
            }
        }

        fn mk(&mut self) {
            if self.executable {
                let mut path = self.path.clone().into_os_string();
                write!(path, "{}", env::consts::EXE_SUFFIX).unwrap();
                self.path = path.into();
            }

            self.dirname().mkdir_p();
            fs::write(&self.path, &self.body)
                .unwrap_or_else(|e| panic!("could not create file {}: {}", self.path.display(), e));

            #[cfg(unix)]
            if self.executable {
                use std::os::unix::fs::PermissionsExt;

                let mut perms = fs::metadata(&self.path).unwrap().permissions();
                let mode = perms.mode();
                perms.set_mode(mode | 0o111);
                fs::set_permissions(&self.path, perms).unwrap();
            }
        }

        fn dirname(&self) -> &Path {
            self.path.parent().unwrap()
        }
    }

    #[derive(PartialEq, Clone)]
    struct SymlinkBuilder {
        dst: PathBuf,
        src: PathBuf,
        src_is_dir: bool,
    }

    impl SymlinkBuilder {
        pub fn new(dst: PathBuf, src: PathBuf) -> SymlinkBuilder {
            SymlinkBuilder {
                dst,
                src,
                src_is_dir: false,
            }
        }

        pub fn new_dir(dst: PathBuf, src: PathBuf) -> SymlinkBuilder {
            SymlinkBuilder {
                dst,
                src,
                src_is_dir: true,
            }
        }

        #[cfg(unix)]
        fn mk(&self) {
            self.dirname().mkdir_p();
            t!(os::unix::fs::symlink(&self.dst, &self.src));
        }

        #[cfg(windows)]
        fn mk(&mut self) {
            self.dirname().mkdir_p();
            if self.src_is_dir {
                t!(os::windows::fs::symlink_dir(&self.dst, &self.src));
            } else {
                if let Some(ext) = self.dst.extension() {
                    if ext == env::consts::EXE_EXTENSION {
                        self.src.set_extension(ext);
                    }
                }
                t!(os::windows::fs::symlink_file(&self.dst, &self.src));
            }
        }

        fn dirname(&self) -> &Path {
            self.src.parent().unwrap()
        }
    }

    /// A cargo project to run tests against.
    ///
    /// See [`ProjectBuilder`] or [`Project::from_template`] to get started.
    pub struct Project {
        root: PathBuf,
    }

    /// Create a project to run tests against
    ///
    /// The project can be constructed programmatically or from the filesystem with [`Project::from_template`]
    #[must_use]
    pub struct ProjectBuilder {
        root: Project,
        files: Vec<FileBuilder>,
        symlinks: Vec<SymlinkBuilder>,
        no_manifest: bool,
    }

    impl ProjectBuilder {
        /// Root of the project, ex: `/path/to/cargo/target/cit/t0/foo`
        pub fn root(&self) -> PathBuf {
            self.root.root()
        }

        /// Project's debug dir, ex: `/path/to/cargo/target/cit/t0/foo/target/debug`
        pub fn target_debug_dir(&self) -> PathBuf {
            self.root.target_debug_dir()
        }

        pub fn new(root: PathBuf) -> ProjectBuilder {
            ProjectBuilder {
                root: Project { root },
                files: vec![],
                symlinks: vec![],
                no_manifest: false,
            }
        }

        pub fn at<P: AsRef<Path>>(mut self, path: P) -> Self {
            self.root = Project {
                root: paths::root().join(path),
            };
            self
        }

        /// Adds a file to the project.
        pub fn file<B: AsRef<Path>>(mut self, path: B, body: &str) -> Self {
            self._file(path.as_ref(), body, false);
            self
        }

        /// Adds an executable file to the project.
        pub fn executable<B: AsRef<Path>>(mut self, path: B, body: &str) -> Self {
            self._file(path.as_ref(), body, true);
            self
        }

        fn _file(&mut self, path: &Path, body: &str, executable: bool) {
            self.files.push(FileBuilder::new(
                self.root.root().join(path),
                body,
                executable,
            ));
        }

        /// Adds a symlink to a file to the project.
        pub fn symlink<T: AsRef<Path>>(mut self, dst: T, src: T) -> Self {
            self.symlinks.push(SymlinkBuilder::new(
                self.root.root().join(dst),
                self.root.root().join(src),
            ));
            self
        }

        /// Create a symlink to a directory
        pub fn symlink_dir<T: AsRef<Path>>(mut self, dst: T, src: T) -> Self {
            self.symlinks.push(SymlinkBuilder::new_dir(
                self.root.root().join(dst),
                self.root.root().join(src),
            ));
            self
        }

        pub fn no_manifest(mut self) -> Self {
            self.no_manifest = true;
            self
        }

        /// Creates the project.
        pub fn build(mut self) -> Project {
            // First, clean the directory if it already exists
            self.rm_root();

            // Create the empty directory
            self.root.root().mkdir_p();

            let manifest_path = self.root.root().join("Cargo.toml");
            if !self.no_manifest && self.files.iter().all(|fb| fb.path != manifest_path) {
                self._file(
                    Path::new("Cargo.toml"),
                    &basic_manifest("foo", "0.0.1"),
                    false,
                )
            }

            let past = time::SystemTime::now() - Duration::new(1, 0);
            let ftime = filetime::FileTime::from_system_time(past);

            for file in self.files.iter_mut() {
                file.mk();
                if is_coarse_mtime() {
                    // Place the entire project 1 second in the past to ensure
                    // that if cargo is called multiple times, the 2nd call will
                    // see targets as "fresh". Without this, if cargo finishes in
                    // under 1 second, the second call will see the mtime of
                    // source == mtime of output and consider it dirty.
                    filetime::set_file_times(&file.path, ftime, ftime).unwrap();
                }
            }

            for symlink in self.symlinks.iter_mut() {
                symlink.mk();
            }

            let ProjectBuilder { root, .. } = self;
            root
        }

        fn rm_root(&self) {
            self.root.root().rm_rf()
        }
    }

    impl Project {
        /// Copy the test project from a fixed state
        pub fn from_template(template_path: impl AsRef<std::path::Path>) -> Self {
            let root = paths::root();
            let project_root = root.join("case");
            snapbox::path::copy_template(template_path.as_ref(), &project_root).unwrap();
            Self { root: project_root }
        }

        /// Root of the project, ex: `/path/to/cargo/target/cit/t0/foo`
        pub fn root(&self) -> PathBuf {
            self.root.clone()
        }

        /// Project's target dir, ex: `/path/to/cargo/target/cit/t0/foo/target`
        pub fn build_dir(&self) -> PathBuf {
            self.root().join("target")
        }

        /// Project's debug dir, ex: `/path/to/cargo/target/cit/t0/foo/target/debug`
        pub fn target_debug_dir(&self) -> PathBuf {
            self.build_dir().join("debug")
        }

        /// File url for root, ex: `file:///path/to/cargo/target/cit/t0/foo`
        pub fn url(&self) -> Url {
            path2url(self.root())
        }

        /// Path to an example built as a library.
        /// `kind` should be one of: "lib", "rlib", "staticlib", "dylib", "proc-macro"
        /// ex: `/path/to/cargo/target/cit/t0/foo/target/debug/examples/libex.rlib`
        pub fn example_lib(&self, name: &str, kind: &str) -> PathBuf {
            self.target_debug_dir()
                .join("examples")
                .join(paths::get_lib_filename(name, kind))
        }

        /// Path to a debug binary.
        /// ex: `/path/to/cargo/target/cit/t0/foo/target/debug/foo`
        pub fn bin(&self, b: &str) -> PathBuf {
            self.build_dir()
                .join("debug")
                .join(&format!("{}{}", b, env::consts::EXE_SUFFIX))
        }

        /// Path to a release binary.
        /// ex: `/path/to/cargo/target/cit/t0/foo/target/release/foo`
        pub fn release_bin(&self, b: &str) -> PathBuf {
            self.build_dir()
                .join("release")
                .join(&format!("{}{}", b, env::consts::EXE_SUFFIX))
        }

        /// Path to a debug binary for a specific target triple.
        /// ex: `/path/to/cargo/target/cit/t0/foo/target/i686-apple-darwin/debug/foo`
        pub fn target_bin(&self, target: &str, b: &str) -> PathBuf {
            self.build_dir().join(target).join("debug").join(&format!(
                "{}{}",
                b,
                env::consts::EXE_SUFFIX
            ))
        }

        /// Returns an iterator of paths matching the glob pattern, which is
        /// relative to the project root.
        pub fn glob<P: AsRef<Path>>(&self, pattern: P) -> glob::Paths {
            let pattern = self.root().join(pattern);
            glob::glob(pattern.to_str().expect("failed to convert pattern to str"))
                .expect("failed to glob")
        }

        /// Changes the contents of an existing file.
        pub fn change_file(&self, path: &str, body: &str) {
            FileBuilder::new(self.root().join(path), body, false).mk()
        }

        /// Creates a `ProcessBuilder` to run a program in the project
        /// and wrap it in an Execs to assert on the execution.
        /// Example:
        ///         p.process(&p.bin("foo"))
        ///             .with_stdout("bar\n")
        ///             .run();
        pub fn process<T: AsRef<OsStr>>(&self, program: T) -> Execs {
            let mut p = process(program);
            p.cwd(self.root());
            execs().with_process_builder(p)
        }

        /// Creates a `ProcessBuilder` to run cargo.
        /// Arguments can be separated by spaces.
        /// Example:
        ///     p.cargo("build --bin foo").run();
        pub fn cargo(&self, cmd: &str) -> Execs {
            let cargo = cargo_exe();
            let mut execs = self.process(&cargo);
            if let Some(ref mut p) = execs.process_builder {
                p.env("CARGO", cargo);
                p.arg_line(cmd);
            }
            execs
        }

        /// Safely run a process after `cargo build`.
        ///
        /// Windows has a problem where a process cannot be reliably
        /// be replaced, removed, or renamed immediately after executing it.
        /// The action may fail (with errors like Access is denied), or
        /// it may succeed, but future attempts to use the same filename
        /// will fail with "Already Exists".
        ///
        /// If you have a test that needs to do `cargo run` multiple
        /// times, you should instead use `cargo build` and use this
        /// method to run the executable. Each time you call this,
        /// use a new name for `dst`.
        /// See rust-lang/cargo#5481.
        pub fn rename_run(&self, src: &str, dst: &str) -> Execs {
            let src = self.bin(src);
            let dst = self.bin(dst);
            fs::rename(&src, &dst)
                .unwrap_or_else(|e| panic!("Failed to rename `{:?}` to `{:?}`: {}", src, dst, e));
            self.process(dst)
        }

        /// Returns the contents of `Cargo.lock`.
        pub fn read_lockfile(&self) -> String {
            self.read_file("Cargo.lock")
        }

        /// Returns the contents of a path in the project root
        pub fn read_file(&self, path: &str) -> String {
            let full = self.root().join(path);
            fs::read_to_string(&full)
                .unwrap_or_else(|e| panic!("could not read file {}: {}", full.display(), e))
        }

        /// Modifies `Cargo.toml` to remove all commented lines.
        pub fn uncomment_root_manifest(&self) {
            let contents = self.read_file("Cargo.toml").replace("#", "");
            fs::write(self.root().join("Cargo.toml"), contents).unwrap();
        }

        pub fn symlink(&self, src: impl AsRef<Path>, dst: impl AsRef<Path>) {
            let src = self.root().join(src.as_ref());
            let dst = self.root().join(dst.as_ref());
            #[cfg(unix)]
            {
                if let Err(e) = os::unix::fs::symlink(&src, &dst) {
                    panic!("failed to symlink {:?} to {:?}: {:?}", src, dst, e);
                }
            }
            #[cfg(windows)]
            {
                if src.is_dir() {
                    if let Err(e) = os::windows::fs::symlink_dir(&src, &dst) {
                        panic!("failed to symlink {:?} to {:?}: {:?}", src, dst, e);
                    }
                } else {
                    if let Err(e) = os::windows::fs::symlink_file(&src, &dst) {
                        panic!("failed to symlink {:?} to {:?}: {:?}", src, dst, e);
                    }
                }
            }
        }
    }

    // Generates a project layout
    pub fn project() -> ProjectBuilder {
        ProjectBuilder::new(paths::root().join("foo"))
    }

    // Generates a project layout in given directory
    pub fn project_in(dir: &str) -> ProjectBuilder {
        ProjectBuilder::new(paths::root().join(dir).join("foo"))
    }

    // Generates a project layout inside our fake home dir
    pub fn project_in_home(name: &str) -> ProjectBuilder {
        ProjectBuilder::new(paths::home().join(name))
    }

    // === Helpers ===

    pub fn main_file(println: &str, deps: &[&str]) -> String {
        let mut buf = String::new();

        for dep in deps.iter() {
            buf.push_str(&format!("extern crate {};\n", dep));
        }

        buf.push_str("fn main() { println!(");
        buf.push_str(println);
        buf.push_str("); }\n");

        buf
    }

    pub fn cargo_exe() -> PathBuf {
        snapbox::cmd::cargo_bin("cargo")
    }

    /// This is the raw output from the process.
    ///
    /// This is similar to `std::process::Output`, however the `status` is
    /// translated to the raw `code`. This is necessary because `ProcessError`
    /// does not have access to the raw `ExitStatus` because `ProcessError` needs
    /// to be serializable (for the Rustc cache), and `ExitStatus` does not
    /// provide a constructor.
    pub struct RawOutput {
        pub code: Option<i32>,
        pub stdout: Vec<u8>,
        pub stderr: Vec<u8>,
    }

    #[must_use]
    #[derive(Clone)]
    pub struct Execs {
        ran: bool,
        process_builder: Option<ProcessBuilder>,
        expect_stdout: Option<String>,
        expect_stdin: Option<String>,
        expect_stderr: Option<String>,
        expect_exit_code: Option<i32>,
        expect_stdout_contains: Vec<String>,
        expect_stderr_contains: Vec<String>,
        expect_stdout_contains_n: Vec<(String, usize)>,
        expect_stdout_not_contains: Vec<String>,
        expect_stderr_not_contains: Vec<String>,
        expect_stdout_unordered: Vec<String>,
        expect_stderr_unordered: Vec<String>,
        expect_stderr_with_without: Vec<(Vec<String>, Vec<String>)>,
        expect_json: Option<String>,
        expect_json_contains_unordered: Option<String>,
        stream_output: bool,
    }

    impl Execs {
        pub fn with_process_builder(mut self, p: ProcessBuilder) -> Execs {
            self.process_builder = Some(p);
            self
        }

        /// Verifies that stdout is equal to the given lines.
        /// See [`compare`] for supported patterns.
        pub fn with_stdout<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stdout = Some(expected.to_string());
            self
        }

        /// Verifies that stderr is equal to the given lines.
        /// See [`compare`] for supported patterns.
        pub fn with_stderr<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stderr = Some(expected.to_string());
            self
        }

        /// Writes the given lines to stdin.
        pub fn with_stdin<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stdin = Some(expected.to_string());
            self
        }

        /// Verifies the exit code from the process.
        ///
        /// This is not necessary if the expected exit code is `0`.
        pub fn with_status(&mut self, expected: i32) -> &mut Self {
            self.expect_exit_code = Some(expected);
            self
        }

        /// Removes exit code check for the process.
        ///
        /// By default, the expected exit code is `0`.
        pub fn without_status(&mut self) -> &mut Self {
            self.expect_exit_code = None;
            self
        }

        /// Verifies that stdout contains the given contiguous lines somewhere in
        /// its output.
        ///
        /// See [`compare`] for supported patterns.
        pub fn with_stdout_contains<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stdout_contains.push(expected.to_string());
            self
        }

        /// Verifies that stderr contains the given contiguous lines somewhere in
        /// its output.
        ///
        /// See [`compare`] for supported patterns.
        pub fn with_stderr_contains<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stderr_contains.push(expected.to_string());
            self
        }

        /// Verifies that stdout contains the given contiguous lines somewhere in
        /// its output, and should be repeated `number` times.
        ///
        /// See [`compare`] for supported patterns.
        pub fn with_stdout_contains_n<S: ToString>(&mut self, expected: S, number: usize) -> &mut Self {
            self.expect_stdout_contains_n
                .push((expected.to_string(), number));
            self
        }

        /// Verifies that stdout does not contain the given contiguous lines.
        ///
        /// See [`compare`] for supported patterns.
        ///
        /// See note on [`Self::with_stderr_does_not_contain`].
        pub fn with_stdout_does_not_contain<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stdout_not_contains.push(expected.to_string());
            self
        }

        /// Verifies that stderr does not contain the given contiguous lines.
        ///
        /// See [`compare`] for supported patterns.
        ///
        /// Care should be taken when using this method because there is a
        /// limitless number of possible things that *won't* appear. A typo means
        /// your test will pass without verifying the correct behavior. If
        /// possible, write the test first so that it fails, and then implement
        /// your fix/feature to make it pass.
        pub fn with_stderr_does_not_contain<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stderr_not_contains.push(expected.to_string());
            self
        }

        /// Verifies that all of the stdout output is equal to the given lines,
        /// ignoring the order of the lines.
        ///
        /// See [`Execs::with_stderr_unordered`] for more details.
        pub fn with_stdout_unordered<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stdout_unordered.push(expected.to_string());
            self
        }

        /// Verifies that all of the stderr output is equal to the given lines,
        /// ignoring the order of the lines.
        ///
        /// See [`compare`] for supported patterns.
        ///
        /// This is useful when checking the output of `cargo build -v` since
        /// the order of the output is not always deterministic.
        /// Recommend use `with_stderr_contains` instead unless you really want to
        /// check *every* line of output.
        ///
        /// Be careful when using patterns such as `[..]`, because you may end up
        /// with multiple lines that might match, and this is not smart enough to
        /// do anything like longest-match. For example, avoid something like:
        ///
        /// ```text
        ///  [RUNNING] `rustc [..]
        ///  [RUNNING] `rustc --crate-name foo [..]
        /// ```
        ///
        /// This will randomly fail if the other crate name is `bar`, and the
        /// order changes.
        pub fn with_stderr_unordered<S: ToString>(&mut self, expected: S) -> &mut Self {
            self.expect_stderr_unordered.push(expected.to_string());
            self
        }

        /// Verify that a particular line appears in stderr with and without the
        /// given substrings. Exactly one line must match.
        ///
        /// The substrings are matched as `contains`. Example:
        ///
        /// ```no_run
        /// use cargo_test_support::execs;
        ///
        /// execs().with_stderr_line_without(
        ///     &[
        ///         "[RUNNING] `rustc --crate-name build_script_build",
        ///         "-C opt-level=3",
        ///     ],
        ///     &["-C debuginfo", "-C incremental"],
        /// );
        /// ```
        ///
        /// This will check that a build line includes `-C opt-level=3` but does
        /// not contain `-C debuginfo` or `-C incremental`.
        ///
        /// Be careful writing the `without` fragments, see note in
        /// `with_stderr_does_not_contain`.
        pub fn with_stderr_line_without<S: ToString>(
            &mut self,
            with: &[S],
            without: &[S],
        ) -> &mut Self {
            let with = with.iter().map(|s| s.to_string()).collect();
            let without = without.iter().map(|s| s.to_string()).collect();
            self.expect_stderr_with_without.push((with, without));
            self
        }

        /// Verifies the JSON output matches the given JSON.
        ///
        /// This is typically used when testing cargo commands that emit JSON.
        /// Each separate JSON object should be separated by a blank line.
        /// Example:
        ///
        /// ```rust,ignore
        /// assert_that(
        ///     p.cargo("metadata"),
        ///     execs().with_json(r#"
        ///         {"example": "abc"}
        ///
        ///         {"example": "def"}
        ///     "#)
        ///  );
        /// ```
        ///
        /// - Objects should match in the order given.
        /// - The order of arrays is ignored.
        /// - Strings support patterns described in [`compare`].
        /// - Use `"{...}"` to match any object.
        pub fn with_json(&mut self, expected: &str) -> &mut Self {
            self.expect_json = Some(expected.to_string());
            self
        }

        /// Verifies JSON output contains the given objects (in any order) somewhere
        /// in its output.
        ///
        /// CAUTION: Be very careful when using this. Make sure every object is
        /// unique (not a subset of one another). Also avoid using objects that
        /// could possibly match multiple output lines unless you're very sure of
        /// what you are doing.
        ///
        /// See `with_json` for more detail.
        pub fn with_json_contains_unordered(&mut self, expected: &str) -> &mut Self {
            match &mut self.expect_json_contains_unordered {
                None => self.expect_json_contains_unordered = Some(expected.to_string()),
                Some(e) => {
                    e.push_str("\n\n");
                    e.push_str(expected);
                }
            }
            self
        }

        /// Forward subordinate process stdout/stderr to the terminal.
        /// Useful for printf debugging of the tests.
        /// CAUTION: CI will fail if you leave this in your test!
        #[allow(unused)]
        pub fn stream(&mut self) -> &mut Self {
            self.stream_output = true;
            self
        }

        pub fn arg<T: AsRef<OsStr>>(&mut self, arg: T) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                p.arg(arg);
            }
            self
        }

        pub fn args<T: AsRef<OsStr>>(&mut self, args: &[T]) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                p.args(args);
            }
            self
        }

        pub fn cwd<T: AsRef<OsStr>>(&mut self, path: T) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                if let Some(cwd) = p.get_cwd() {
                    let new_path = cwd.join(path.as_ref());
                    p.cwd(new_path);
                } else {
                    p.cwd(path);
                }
            }
            self
        }

        fn get_cwd(&self) -> Option<&Path> {
            self.process_builder.as_ref().and_then(|p| p.get_cwd())
        }

        pub fn env<T: AsRef<OsStr>>(&mut self, key: &str, val: T) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                p.env(key, val);
            }
            self
        }

        pub fn env_remove(&mut self, key: &str) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                p.env_remove(key);
            }
            self
        }

        pub fn exec_with_output(&mut self) -> Result<Output> {
            self.ran = true;
            // TODO avoid unwrap
            let p = (&self.process_builder).clone().unwrap();
            p.exec_with_output()
        }

        pub fn build_command(&mut self) -> Command {
            self.ran = true;
            // TODO avoid unwrap
            let p = (&self.process_builder).clone().unwrap();
            p.build_command()
        }

        /// Enables nightly features for testing
        ///
        /// The list of reasons should be why nightly cargo is needed. If it is
        /// because of an unstable feature put the name of the feature as the reason,
        /// e.g. `&["print-im-a-teapot"]`
        pub fn masquerade_as_nightly_cargo(&mut self, reasons: &[&str]) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                p.masquerade_as_nightly_cargo(reasons);
            }
            self
        }

        /// Overrides the crates.io URL for testing.
        ///
        /// Can be used for testing crates-io functionality where alt registries
        /// cannot be used.
        pub fn replace_crates_io(&mut self, url: &Url) -> &mut Self {
            if let Some(ref mut p) = self.process_builder {
                p.env("__CARGO_TEST_CRATES_IO_URL_DO_NOT_USE_THIS", url.as_str());
            }
            self
        }

        pub fn enable_split_debuginfo_packed(&mut self) -> &mut Self {
            self.env("CARGO_PROFILE_DEV_SPLIT_DEBUGINFO", "packed")
                .env("CARGO_PROFILE_TEST_SPLIT_DEBUGINFO", "packed")
                .env("CARGO_PROFILE_RELEASE_SPLIT_DEBUGINFO", "packed")
                .env("CARGO_PROFILE_BENCH_SPLIT_DEBUGINFO", "packed");
            self
        }

        pub fn enable_mac_dsym(&mut self) -> &mut Self {
            if cfg!(target_os = "macos") {
                return self.enable_split_debuginfo_packed();
            }
            self
        }

        #[track_caller]
        pub fn run(&mut self) {
            self.ran = true;
            let mut p = (&self.process_builder).clone().unwrap();
            if let Some(stdin) = self.expect_stdin.take() {
                p.stdin(stdin);
            }
            if let Err(e) = self.match_process(&p) {
                panic_error(&format!("test failed running {}", p), e);
            }
        }

        #[track_caller]
        pub fn run_expect_error(&mut self) {
            self.ran = true;
            let p = (&self.process_builder).clone().unwrap();
            if self.match_process(&p).is_ok() {
                panic!("test was expected to fail, but succeeded running {}", p);
            }
        }

        /// Runs the process, checks the expected output, and returns the first
        /// JSON object on stdout.
        #[track_caller]
        pub fn run_json(&mut self) -> serde_json::Value {
            self.ran = true;
            let p = (&self.process_builder).clone().unwrap();
            match self.match_process(&p) {
                Err(e) => panic_error(&format!("test failed running {}", p), e),
                Ok(output) => serde_json::from_slice(&output.stdout).unwrap_or_else(|e| {
                    panic!(
                        "\nfailed to parse JSON: {}\n\
                         output was:\n{}\n",
                        e,
                        String::from_utf8_lossy(&output.stdout)
                    );
                }),
            }
        }

        #[track_caller]
        pub fn run_output(&mut self, output: &Output) {
            self.ran = true;
            if let Err(e) = self.match_output(output.status.code(), &output.stdout, &output.stderr) {
                panic_error("process did not return the expected result", e)
            }
        }

        fn verify_checks_output(&self, stdout: &[u8], stderr: &[u8]) {
            if self.expect_exit_code.unwrap_or(0) != 0
                && self.expect_stdout.is_none()
                && self.expect_stdin.is_none()
                && self.expect_stderr.is_none()
                && self.expect_stdout_contains.is_empty()
                && self.expect_stderr_contains.is_empty()
                && self.expect_stdout_contains_n.is_empty()
                && self.expect_stdout_not_contains.is_empty()
                && self.expect_stderr_not_contains.is_empty()
                && self.expect_stdout_unordered.is_empty()
                && self.expect_stderr_unordered.is_empty()
                && self.expect_stderr_with_without.is_empty()
                && self.expect_json.is_none()
                && self.expect_json_contains_unordered.is_none()
            {
                panic!(
                    "`with_status()` is used, but no output is checked.\n\
                     The test must check the output to ensure the correct error is triggered.\n\
                     --- stdout\n{}\n--- stderr\n{}",
                    String::from_utf8_lossy(stdout),
                    String::from_utf8_lossy(stderr),
                );
            }
        }

        fn match_process(&self, process: &ProcessBuilder) -> Result<RawOutput> {
            println!("running {}", process);
            let res = if self.stream_output {
                if is_ci() {
                    panic!("`.stream()` is for local debugging")
                }
                process.exec_with_streaming(
                    &mut |out| {
                        println!("{}", out);
                        Ok(())
                    },
                    &mut |err| {
                        eprintln!("{}", err);
                        Ok(())
                    },
                    true,
                )
            } else {
                process.exec_with_output()
            };

            match res {
                Ok(out) => {
                    self.match_output(out.status.code(), &out.stdout, &out.stderr)?;
                    return Ok(RawOutput {
                        stdout: out.stdout,
                        stderr: out.stderr,
                        code: out.status.code(),
                    });
                }
                Err(e) => {
                    if let Some(ProcessError {
                        stdout: Some(stdout),
                        stderr: Some(stderr),
                        code,
                        ..
                    }) = e.downcast_ref::<ProcessError>()
                    {
                        self.match_output(*code, stdout, stderr)?;
                        return Ok(RawOutput {
                            stdout: stdout.to_vec(),
                            stderr: stderr.to_vec(),
                            code: *code,
                        });
                    }
                    bail!("could not exec process {}: {:?}", process, e)
                }
            }
        }

        fn match_output(&self, code: Option<i32>, stdout: &[u8], stderr: &[u8]) -> Result<()> {
            self.verify_checks_output(stdout, stderr);
            let stdout = std::str::from_utf8(stdout).expect("stdout is not utf8");
            let stderr = std::str::from_utf8(stderr).expect("stderr is not utf8");
            let cwd = self.get_cwd();

            match self.expect_exit_code {
                None => {}
                Some(expected) if code == Some(expected) => {}
                Some(expected) => bail!(
                    "process exited with code {} (expected {})\n--- stdout\n{}\n--- stderr\n{}",
                    code.unwrap_or(-1),
                    expected,
                    stdout,
                    stderr
                ),
            }

            if let Some(expect_stdout) = &self.expect_stdout {
                compare::match_exact(expect_stdout, stdout, "stdout", stderr, cwd)?;
            }
            if let Some(expect_stderr) = &self.expect_stderr {
                compare::match_exact(expect_stderr, stderr, "stderr", stdout, cwd)?;
            }
            for expect in self.expect_stdout_contains.iter() {
                compare::match_contains(expect, stdout, cwd)?;
            }
            for expect in self.expect_stderr_contains.iter() {
                compare::match_contains(expect, stderr, cwd)?;
            }
            for &(ref expect, number) in self.expect_stdout_contains_n.iter() {
                compare::match_contains_n(expect, number, stdout, cwd)?;
            }
            for expect in self.expect_stdout_not_contains.iter() {
                compare::match_does_not_contain(expect, stdout, cwd)?;
            }
            for expect in self.expect_stderr_not_contains.iter() {
                compare::match_does_not_contain(expect, stderr, cwd)?;
            }
            for expect in self.expect_stdout_unordered.iter() {
                compare::match_unordered(expect, stdout, cwd)?;
            }
            for expect in self.expect_stderr_unordered.iter() {
                compare::match_unordered(expect, stderr, cwd)?;
            }
            for (with, without) in self.expect_stderr_with_without.iter() {
                compare::match_with_without(stderr, with, without, cwd)?;
            }

            if let Some(ref expect_json) = self.expect_json {
                compare::match_json(expect_json, stdout, cwd)?;
            }

            if let Some(ref expected) = self.expect_json_contains_unordered {
                compare::match_json_contains_unordered(expected, stdout, cwd)?;
            }
            Ok(())
        }
    }

    impl Drop for Execs {
        fn drop(&mut self) {
            if !self.ran && !std::thread::panicking() {
                panic!("forgot to run this command");
            }
        }
    }

    pub fn execs() -> Execs {
        Execs {
            ran: false,
            process_builder: None,
            expect_stdout: None,
            expect_stderr: None,
            expect_stdin: None,
            expect_exit_code: Some(0),
            expect_stdout_contains: Vec::new(),
            expect_stderr_contains: Vec::new(),
            expect_stdout_contains_n: Vec::new(),
            expect_stdout_not_contains: Vec::new(),
            expect_stderr_not_contains: Vec::new(),
            expect_stdout_unordered: Vec::new(),
            expect_stderr_unordered: Vec::new(),
            expect_stderr_with_without: Vec::new(),
            expect_json: None,
            expect_json_contains_unordered: None,
            stream_output: false,
        }
    }

    pub fn basic_manifest(name: &str, version: &str) -> String {
        format!(
            r#"
            [package]
            name = "{}"
            version = "{}"
            authors = []
            edition = "2015"
        "#,
            name, version
        )
    }

    pub fn basic_bin_manifest(name: &str) -> String {
        format!(
            r#"
            [package]

            name = "{}"
            version = "0.5.0"
            authors = ["wycats@example.com"]
            edition = "2015"

            [[bin]]

            name = "{}"
        "#,
            name, name
        )
    }

    pub fn basic_lib_manifest(name: &str) -> String {
        format!(
            r#"
            [package]

            name = "{}"
            version = "0.5.0"
            authors = ["wycats@example.com"]
            edition = "2015"

            [lib]

            name = "{}"
        "#,
            name, name
        )
    }

    pub fn path2url<P: AsRef<Path>>(p: P) -> Url {
        Url::from_file_path(p).ok().unwrap()
    }

    struct RustcInfo {
        verbose_version: String,
        host: String,
    }

    impl RustcInfo {
        fn new() -> RustcInfo {
            let output = ProcessBuilder::new("rustc")
                .arg("-vV")
                .exec_with_output()
                .expect("rustc should exec");
            let verbose_version = String::from_utf8(output.stdout).expect("utf8 output");
            let host = verbose_version
                .lines()
                .filter_map(|line| line.strip_prefix("host: "))
                .next()
                .expect("verbose version has host: field")
                .to_string();
            RustcInfo {
                verbose_version,
                host,
            }
        }
    }

    fn rustc_info() -> &'static RustcInfo {
        static RUSTC_INFO: OnceLock<RustcInfo> = OnceLock::new();
        RUSTC_INFO.get_or_init(RustcInfo::new)
    }

    /// The rustc host such as `x86_64-unknown-linux-gnu`.
    pub fn rustc_host() -> &'static str {
        &rustc_info().host
    }

    /// The host triple suitable for use in a cargo environment variable (uppercased).
    pub fn rustc_host_env() -> String {
        rustc_host().to_uppercase().replace('-', "_")
    }

    pub fn is_nightly() -> bool {
        let vv = &rustc_info().verbose_version;
        // CARGO_TEST_DISABLE_NIGHTLY is set in rust-lang/rust's CI so that all
        // nightly-only tests are disabled there. Otherwise, it could make it
        // difficult to land changes which would need to be made simultaneously in
        // rust-lang/cargo and rust-lan/rust, which isn't possible.
        env::var("CARGO_TEST_DISABLE_NIGHTLY").is_err()
            && (vv.contains("-nightly") || vv.contains("-dev"))
    }

    pub fn process<T: AsRef<OsStr>>(t: T) -> ProcessBuilder {
        _process(t.as_ref())
    }

    fn _process(t: &OsStr) -> ProcessBuilder {
        let mut p = ProcessBuilder::new(t);
        p.cwd(&paths::root()).test_env();
        p
    }

    /// Enable nightly features for testing
    pub trait ChannelChanger {
        /// The list of reasons should be why nightly cargo is needed. If it is
        /// because of an unstable feature put the name of the feature as the reason,
        /// e.g. `&["print-im-a-teapot"]`.
        fn masquerade_as_nightly_cargo(self, _reasons: &[&str]) -> Self;
    }

    impl ChannelChanger for &mut ProcessBuilder {
        fn masquerade_as_nightly_cargo(self, _reasons: &[&str]) -> Self {
            self.env("__CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS", "nightly")
        }
    }

    impl ChannelChanger for snapbox::cmd::Command {
        fn masquerade_as_nightly_cargo(self, _reasons: &[&str]) -> Self {
            self.env("__CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS", "nightly")
        }
    }

    /// Establish a process's test environment
    pub trait TestEnv: Sized {
        fn test_env(mut self) -> Self {
            // In general just clear out all cargo-specific configuration already in the
            // environment. Our tests all assume a "default configuration" unless
            // specified otherwise.
            for (k, _v) in env::vars() {
                if k.starts_with("CARGO_") {
                    self = self.env_remove(&k);
                }
            }
            if env::var_os("RUSTUP_TOOLCHAIN").is_some() {
                // Override the PATH to avoid executing the rustup wrapper thousands
                // of times. This makes the testsuite run substantially faster.
                static RUSTC_DIR: OnceLock<PathBuf> = OnceLock::new();
                let rustc_dir = RUSTC_DIR.get_or_init(|| {
                    match ProcessBuilder::new("rustup")
                        .args(&["which", "rustc"])
                        .exec_with_output()
                    {
                        Ok(output) => {
                            let s = std::str::from_utf8(&output.stdout).expect("utf8").trim();
                            let mut p = PathBuf::from(s);
                            p.pop();
                            p
                        }
                        Err(e) => {
                            panic!("RUSTUP_TOOLCHAIN was set, but could not run rustup: {}", e);
                        }
                    }
                });
                let path = env::var_os("PATH").unwrap_or_default();
                let paths = env::split_paths(&path);
                let new_path =
                    env::join_paths(std::iter::once(rustc_dir.clone()).chain(paths)).unwrap();
                self = self.env("PATH", new_path);
            }

            self = self
                .current_dir(&paths::root())
                .env("HOME", paths::home())
                .env("CARGO_HOME", paths::home().join(".cargo"))
                .env("__CARGO_TEST_ROOT", paths::global_root())
                // Force Cargo to think it's on the stable channel for all tests, this
                // should hopefully not surprise us as we add cargo features over time and
                // cargo rides the trains.
                .env("__CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS", "stable")
                // Keeps cargo within its sandbox.
                .env("__CARGO_TEST_DISABLE_GLOBAL_KNOWN_HOST", "1")
                // Set retry sleep to 1 millisecond.
                .env("__CARGO_TEST_FIXED_RETRY_SLEEP_MS", "1")
                // Incremental generates a huge amount of data per test, which we
                // don't particularly need. Tests that specifically need to check
                // the incremental behavior should turn this back on.
                .env("CARGO_INCREMENTAL", "0")
                // Don't read the system git config which is out of our control.
                .env("GIT_CONFIG_NOSYSTEM", "1")
                .env_remove("__CARGO_DEFAULT_LIB_METADATA")
                .env_remove("ALL_PROXY")
                .env_remove("EMAIL")
                .env_remove("GIT_AUTHOR_EMAIL")
                .env_remove("GIT_AUTHOR_NAME")
                .env_remove("GIT_COMMITTER_EMAIL")
                .env_remove("GIT_COMMITTER_NAME")
                .env_remove("http_proxy")
                .env_remove("HTTPS_PROXY")
                .env_remove("https_proxy")
                .env_remove("MAKEFLAGS")
                .env_remove("MFLAGS")
                .env_remove("MSYSTEM") // assume cmd.exe everywhere on windows
                .env_remove("RUSTC")
                .env_remove("RUSTC_WORKSPACE_WRAPPER")
                .env_remove("RUSTC_WRAPPER")
                .env_remove("RUSTDOC")
                .env_remove("RUSTDOCFLAGS")
                .env_remove("RUSTFLAGS")
                .env_remove("SSH_AUTH_SOCK") // ensure an outer agent is never contacted
                .env_remove("USER") // not set on some rust-lang docker images
                .env_remove("XDG_CONFIG_HOME") // see #2345
                .env_remove("OUT_DIR"); // see #13204
            if cfg!(target_os = "macos") {
                // Work-around a bug in macOS 10.15, see `link_or_copy` for details.
                self = self.env("__CARGO_COPY_DONT_LINK_DO_NOT_USE_THIS", "1");
            }
            if cfg!(windows) {
                self = self.env("USERPROFILE", paths::home());
            }
            self
        }

        fn current_dir<S: AsRef<std::path::Path>>(self, path: S) -> Self;
        fn env<S: AsRef<std::ffi::OsStr>>(self, key: &str, value: S) -> Self;
        fn env_remove(self, key: &str) -> Self;
    }

    impl TestEnv for &mut ProcessBuilder {
        fn current_dir<S: AsRef<std::path::Path>>(self, path: S) -> Self {
            let path = path.as_ref();
            self.cwd(path)
        }
        fn env<S: AsRef<std::ffi::OsStr>>(self, key: &str, value: S) -> Self {
            self.env(key, value)
        }
        fn env_remove(self, key: &str) -> Self {
            self.env_remove(key)
        }
    }

    impl TestEnv for snapbox::cmd::Command {
        fn current_dir<S: AsRef<std::path::Path>>(self, path: S) -> Self {
            self.current_dir(path)
        }
        fn env<S: AsRef<std::ffi::OsStr>>(self, key: &str, value: S) -> Self {
            self.env(key, value)
        }
        fn env_remove(self, key: &str) -> Self {
            self.env_remove(key)
        }
    }

    /// Test the cargo command
    pub trait CargoCommand {
        fn cargo_ui() -> Self;
    }

    impl CargoCommand for snapbox::cmd::Command {
        fn cargo_ui() -> Self {
            Self::new(cargo_exe())
                .with_assert(compare::assert_ui())
                .env("CARGO_TERM_COLOR", "always")
                .test_env()
        }
    }

    /// Add a list of arguments as a line
    pub trait ArgLine: Sized {
        fn arg_line(mut self, s: &str) -> Self {
            for mut arg in s.split_whitespace() {
                if (arg.starts_with('"') && arg.ends_with('"'))
                    || (arg.starts_with('\'') && arg.ends_with('\''))
                {
                    arg = &arg[1..(arg.len() - 1).max(1)];
                } else if arg.contains(&['"', '\''][..]) {
                    panic!("shell-style argument parsing is not supported")
                }
                self = self.arg(arg);
            }
            self
        }

        fn arg<S: AsRef<std::ffi::OsStr>>(self, s: S) -> Self;
    }

    impl ArgLine for &mut ProcessBuilder {
        fn arg<S: AsRef<std::ffi::OsStr>>(self, s: S) -> Self {
            self.arg(s)
        }
    }

    impl ArgLine for snapbox::cmd::Command {
        fn arg<S: AsRef<std::ffi::OsStr>>(self, s: S) -> Self {
            self.arg(s)
        }
    }

    pub fn cargo_process(s: &str) -> Execs {
        let cargo = cargo_exe();
        let mut p = process(&cargo);
        p.env("CARGO", cargo);
        p.arg_line(s);
        execs().with_process_builder(p)
    }

    pub fn git_process(s: &str) -> ProcessBuilder {
        let mut p = process("git");
        p.arg_line(s);
        p
    }

    pub fn sleep_ms(ms: u64) {
        ::std::thread::sleep(Duration::from_millis(ms));
    }

    /// Returns `true` if the local filesystem has low-resolution mtimes.
    pub fn is_coarse_mtime() -> bool {
        // If the filetime crate is being used to emulate HFS then
        // return `true`, without looking at the actual hardware.
        cfg!(emulate_second_only_system) ||
        // This should actually be a test that `$CARGO_TARGET_DIR` is on an HFS
        // filesystem, (or any filesystem with low-resolution mtimes). However,
        // that's tricky to detect, so for now just deal with CI.
        cfg!(target_os = "macos") && is_ci()
    }

    /// Some CI setups are much slower then the equipment used by Cargo itself.
    /// Architectures that do not have a modern processor, hardware emulation, etc.
    /// This provides a way for those setups to increase the cut off for all the time based test.
    pub fn slow_cpu_multiplier(main: u64) -> Duration {
        static SLOW_CPU_MULTIPLIER: OnceLock<u64> = OnceLock::new();
        let slow_cpu_multiplier = SLOW_CPU_MULTIPLIER.get_or_init(|| {
            env::var("CARGO_TEST_SLOW_CPU_MULTIPLIER")
                .ok()
                .and_then(|m| m.parse().ok())
                .unwrap_or(1)
        });
        Duration::from_secs(slow_cpu_multiplier * main)
    }

    #[cfg(windows)]
    pub fn symlink_supported() -> bool {
        if is_ci() {
            // We want to be absolutely sure this runs on CI.
            return true;
        }
        let src = paths::root().join("symlink_src");
        fs::write(&src, "").unwrap();
        let dst = paths::root().join("symlink_dst");
        let result = match os::windows::fs::symlink_file(&src, &dst) {
            Ok(_) => {
                fs::remove_file(&dst).unwrap();
                true
            }
            Err(e) => {
                eprintln!(
                    "symlinks not supported: {:?}\n\
                     Windows 10 users should enable developer mode.",
                    e
                );
                false
            }
        };
        fs::remove_file(&src).unwrap();
        return result;
    }

    #[cfg(not(windows))]
    pub fn symlink_supported() -> bool {
        true
    }

    /// The error message for ENOENT.
    pub fn no_such_file_err_msg() -> String {
        std::io::Error::from_raw_os_error(2).to_string()
    }

    /// Helper to retry a function `n` times.
    ///
    /// The function should return `Some` when it is ready.
    pub fn retry<F, R>(n: u32, mut f: F) -> R
    where
        F: FnMut() -> Option<R>,
    {
        let mut count = 0;
        let start = std::time::Instant::now();
        loop {
            if let Some(r) = f() {
                return r;
            }
            count += 1;
            if count > n {
                panic!(
                    "test did not finish within {n} attempts ({:?} total)",
                    start.elapsed()
                );
            }
            sleep_ms(100);
        }
    }

    #[test]
    #[should_panic(expected = "test did not finish")]
    fn retry_fails() {
        retry(2, || None::<()>);
    }

    /// Helper that waits for a thread to finish, up to `n` tenths of a second.
    pub fn thread_wait_timeout<T>(n: u32, thread: JoinHandle<T>) -> T {
        retry(n, || thread.is_finished().then_some(()));
        thread.join().unwrap()
    }

    /// Helper that runs some function, and waits up to `n` tenths of a second for
    /// it to finish.
    pub fn threaded_timeout<F, R>(n: u32, f: F) -> R
    where
        F: FnOnce() -> R + Send + 'static,
        R: Send + 'static,
    {
        let thread = std::thread::spawn(|| f());
        thread_wait_timeout(n, thread)
    }