    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

    // Internal
    use crate::builder::IntoResettable;
    use crate::util::Id;

    /// Family of related [arguments].
    ///
    /// By placing arguments in a logical group, you can create easier requirement and
    /// exclusion rules instead of having to list each argument individually, or when you want a rule
    /// to apply "any but not all" arguments.
    ///
    /// For instance, you can make an entire `ArgGroup` required. If [`ArgGroup::multiple(true)`] is
    /// set, this means that at least one argument from that group must be present. If
    /// [`ArgGroup::multiple(false)`] is set (the default), one and *only* one must be present.
    ///
    /// You can also do things such as name an entire `ArgGroup` as a [conflict] or [requirement] for
    /// another argument, meaning any of the arguments that belong to that group will cause a failure
    /// if present, or must be present respectively.
    ///
    /// Perhaps the most common use of `ArgGroup`s is to require one and *only* one argument to be
    /// present out of a given set. Imagine that you had multiple arguments, and you want one of them
    /// to be required, but making all of them required isn't feasible because perhaps they conflict
    /// with each other. For example, lets say that you were building an application where one could
    /// set a given version number by supplying a string with an option argument, i.e.
    /// `--set-ver v1.2.3`, you also wanted to support automatically using a previous version number
    /// and simply incrementing one of the three numbers. So you create three flags `--major`,
    /// `--minor`, and `--patch`. All of these arguments shouldn't be used at one time but you want to
    /// specify that *at least one* of them is used. For this, you can create a group.
    ///
    /// Finally, you may use `ArgGroup`s to pull a value from a group of arguments when you don't care
    /// exactly which argument was actually used at runtime.
    ///
    /// # Examples
    ///
    /// The following example demonstrates using an `ArgGroup` to ensure that one, and only one, of
    /// the arguments from the specified group is present at runtime.
    ///
    /// ```rust
    /// # use clap::{Command, arg, ArgGroup, error::ErrorKind};
    /// let result = Command::new("cmd")
    ///     .arg(arg!(--"set-ver" <ver> "set the version manually"))
    ///     .arg(arg!(--major           "auto increase major"))
    ///     .arg(arg!(--minor           "auto increase minor"))
    ///     .arg(arg!(--patch           "auto increase patch"))
    ///     .group(ArgGroup::new("vers")
    ///          .args(["set-ver", "major", "minor", "patch"])
    ///          .required(true))
    ///     .try_get_matches_from(vec!["cmd", "--major", "--patch"]);
    /// // Because we used two args in the group it's an error
    /// assert!(result.is_err());
    /// let err = result.unwrap_err();
    /// assert_eq!(err.kind(), ErrorKind::ArgumentConflict);
    /// ```
    ///
    /// This next example shows a passing parse of the same scenario
    /// ```rust
    /// # use clap::{Command, arg, ArgGroup, Id};
    /// let result = Command::new("cmd")
    ///     .arg(arg!(--"set-ver" <ver> "set the version manually"))
    ///     .arg(arg!(--major           "auto increase major"))
    ///     .arg(arg!(--minor           "auto increase minor"))
    ///     .arg(arg!(--patch           "auto increase patch"))
    ///     .group(ArgGroup::new("vers")
    ///          .args(["set-ver", "major", "minor","patch"])
    ///          .required(true))
    ///     .try_get_matches_from(vec!["cmd", "--major"]);
    /// assert!(result.is_ok());
    /// let matches = result.unwrap();
    /// // We may not know which of the args was used, so we can test for the group...
    /// assert!(matches.contains_id("vers"));
    /// // We can also ask the group which arg was used
    /// assert_eq!(matches
    ///     .get_one::<Id>("vers")
    ///     .expect("`vers` is required")
    ///     .as_str(),
    ///     "major"
    /// );
    /// // we could also alternatively check each arg individually (not shown here)
    /// ```
    /// [`ArgGroup::multiple(true)`]: ArgGroup::multiple()
    ///
    /// [`ArgGroup::multiple(false)`]: ArgGroup::multiple()
    /// [arguments]: crate::Arg
    /// [conflict]: crate::Arg::conflicts_with()
    /// [requirement]: crate::Arg::requires()
    #[derive(Default, Clone, Debug, PartialEq, Eq)]
    pub struct ArgGroup {
        pub(crate) id: Id,
        pub(crate) args: Vec<Id>,
        pub(crate) required: bool,
        pub(crate) requires: Vec<Id>,
        pub(crate) conflicts: Vec<Id>,
        pub(crate) multiple: bool,
    }

    /// # Builder
    impl ArgGroup {
        /// Create a `ArgGroup` using a unique name.
        ///
        /// The name will be used to get values from the group or refer to the group inside of conflict
        /// and requirement rules.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, ArgGroup};
        /// ArgGroup::new("config")
        /// # ;
        /// ```
        pub fn new(id: impl Into<Id>) -> Self {
            ArgGroup::default().id(id)
        }

        /// Sets the group name.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, ArgGroup};
        /// ArgGroup::default().id("config")
        /// # ;
        /// ```
        #[must_use]
        pub fn id(mut self, id: impl Into<Id>) -> Self {
            self.id = id.into();
            self
        }

        /// Adds an [argument] to this group by name
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, ArgAction};
        /// let m = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .arg("flag")
        ///         .arg("color"))
        ///     .get_matches_from(vec!["myprog", "-f"]);
        /// // maybe we don't know which of the two flags was used...
        /// assert!(m.contains_id("req_flags"));
        /// // but we can also check individually if needed
        /// assert!(m.contains_id("flag"));
        /// ```
        /// [argument]: crate::Arg
        #[must_use]
        pub fn arg(mut self, arg_id: impl IntoResettable<Id>) -> Self {
            if let Some(arg_id) = arg_id.into_resettable().into_option() {
                self.args.push(arg_id);
            } else {
                self.args.clear();
            }
            self
        }

        /// Adds multiple [arguments] to this group by name
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, ArgAction};
        /// let m = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"]))
        ///     .get_matches_from(vec!["myprog", "-f"]);
        /// // maybe we don't know which of the two flags was used...
        /// assert!(m.contains_id("req_flags"));
        /// // but we can also check individually if needed
        /// assert!(m.contains_id("flag"));
        /// ```
        /// [arguments]: crate::Arg
        #[must_use]
        pub fn args(mut self, ns: impl IntoIterator<Item = impl Into<Id>>) -> Self {
            for n in ns {
                self = self.arg(n);
            }
            self
        }

        /// Getters for all args. It will return a vector of `Id`
        ///
        /// # Example
        ///
        /// ```rust
        /// # use clap::{ArgGroup};
        /// let args: Vec<&str> = vec!["a1".into(), "a4".into()];
        /// let grp = ArgGroup::new("program").args(&args);
        ///
        /// for (pos, arg) in grp.get_args().enumerate() {
        ///     assert_eq!(*arg, args[pos]);
        /// }
        /// ```
        pub fn get_args(&self) -> impl Iterator<Item = &Id> {
            self.args.iter()
        }

        /// Allows more than one of the [`Arg`]s in this group to be used. (Default: `false`)
        ///
        /// # Examples
        ///
        /// Notice in this example we use *both* the `-f` and `-c` flags which are both part of the
        /// group
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, ArgAction};
        /// let m = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"])
        ///         .multiple(true))
        ///     .get_matches_from(vec!["myprog", "-f", "-c"]);
        /// // maybe we don't know which of the two flags was used...
        /// assert!(m.contains_id("req_flags"));
        /// ```
        /// In this next example, we show the default behavior (i.e. `multiple(false)) which will throw
        /// an error if more than one of the args in the group was used.
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, error::ErrorKind, ArgAction};
        /// let result = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"]))
        ///     .try_get_matches_from(vec!["myprog", "-f", "-c"]);
        /// // Because we used both args in the group it's an error
        /// assert!(result.is_err());
        /// let err = result.unwrap_err();
        /// assert_eq!(err.kind(), ErrorKind::ArgumentConflict);
        /// ```
        ///
        /// [`Arg`]: crate::Arg
        #[inline]
        #[must_use]
        pub fn multiple(mut self, yes: bool) -> Self {
            self.multiple = yes;
            self
        }

        /// Return true if the group allows more than one of the arguments
        /// in this group to be used. (Default: `false`)
        ///
        /// # Example
        ///
        /// ```rust
        /// # use clap::{ArgGroup};
        /// let mut group = ArgGroup::new("myprog")
        ///     .args(["f", "c"])
        ///     .multiple(true);
        ///
        /// assert!(group.is_multiple());
        /// ```
        pub fn is_multiple(&mut self) -> bool {
            self.multiple
        }

        /// Require an argument from the group to be present when parsing.
        ///
        /// This is unless conflicting with another argument.  A required group will be displayed in
        /// the usage string of the application in the format `<arg|arg2|arg3>`.
        ///
        /// **NOTE:** This setting only applies to the current [`Command`] / [`Subcommand`]s, and not
        /// globally.
        ///
        /// **NOTE:** By default, [`ArgGroup::multiple`] is set to `false` which when combined with
        /// `ArgGroup::required(true)` states, "One and *only one* arg must be used from this group.
        /// Use of more than one arg is an error." Vice setting `ArgGroup::multiple(true)` which
        /// states, '*At least* one arg from this group must be used. Using multiple is OK."
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, error::ErrorKind, ArgAction};
        /// let result = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"])
        ///         .required(true))
        ///     .try_get_matches_from(vec!["myprog"]);
        /// // Because we didn't use any of the args in the group, it's an error
        /// assert!(result.is_err());
        /// let err = result.unwrap_err();
        /// assert_eq!(err.kind(), ErrorKind::MissingRequiredArgument);
        /// ```
        ///
        /// [`Subcommand`]: crate::Subcommand
        /// [`ArgGroup::multiple`]: ArgGroup::multiple()
        /// [`Command`]: crate::Command
        #[inline]
        #[must_use]
        pub fn required(mut self, yes: bool) -> Self {
            self.required = yes;
            self
        }

        /// Specify an argument or group that must be present when this group is.
        ///
        /// This is not to be confused with a [required group]. Requirement rules function just like
        /// [argument requirement rules], you can name other arguments or groups that must be present
        /// when any one of the arguments from this group is used.
        ///
        /// **NOTE:** The name provided may be an argument or group name
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, error::ErrorKind, ArgAction};
        /// let result = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("debug")
        ///         .short('d')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"])
        ///         .requires("debug"))
        ///     .try_get_matches_from(vec!["myprog", "-c"]);
        /// // because we used an arg from the group, and the group requires "-d" to be used, it's an
        /// // error
        /// assert!(result.is_err());
        /// let err = result.unwrap_err();
        /// assert_eq!(err.kind(), ErrorKind::MissingRequiredArgument);
        /// ```
        /// [required group]: ArgGroup::required()
        /// [argument requirement rules]: crate::Arg::requires()
        #[must_use]
        pub fn requires(mut self, id: impl IntoResettable<Id>) -> Self {
            if let Some(id) = id.into_resettable().into_option() {
                self.requires.push(id);
            } else {
                self.requires.clear();
            }
            self
        }

        /// Specify arguments or groups that must be present when this group is.
        ///
        /// This is not to be confused with a [required group]. Requirement rules function just like
        /// [argument requirement rules], you can name other arguments or groups that must be present
        /// when one of the arguments from this group is used.
        ///
        /// **NOTE:** The names provided may be an argument or group name
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, error::ErrorKind, ArgAction};
        /// let result = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("debug")
        ///         .short('d')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("verb")
        ///         .short('v')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"])
        ///         .requires_all(["debug", "verb"]))
        ///     .try_get_matches_from(vec!["myprog", "-c", "-d"]);
        /// // because we used an arg from the group, and the group requires "-d" and "-v" to be used,
        /// // yet we only used "-d" it's an error
        /// assert!(result.is_err());
        /// let err = result.unwrap_err();
        /// assert_eq!(err.kind(), ErrorKind::MissingRequiredArgument);
        /// ```
        /// [required group]: ArgGroup::required()
        /// [argument requirement rules]: crate::Arg::requires_ifs()
        #[must_use]
        pub fn requires_all(mut self, ns: impl IntoIterator<Item = impl Into<Id>>) -> Self {
            for n in ns {
                self = self.requires(n);
            }
            self
        }

        /// Specify an argument or group that must **not** be present when this group is.
        ///
        /// Exclusion (aka conflict) rules function just like [argument exclusion rules], you can name
        /// other arguments or groups that must *not* be present when one of the arguments from this
        /// group are used.
        ///
        /// **NOTE:** The name provided may be an argument, or group name
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, error::ErrorKind, ArgAction};
        /// let result = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("debug")
        ///         .short('d')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"])
        ///         .conflicts_with("debug"))
        ///     .try_get_matches_from(vec!["myprog", "-c", "-d"]);
        /// // because we used an arg from the group, and the group conflicts with "-d", it's an error
        /// assert!(result.is_err());
        /// let err = result.unwrap_err();
        /// assert_eq!(err.kind(), ErrorKind::ArgumentConflict);
        /// ```
        /// [argument exclusion rules]: crate::Arg::conflicts_with()
        #[must_use]
        pub fn conflicts_with(mut self, id: impl IntoResettable<Id>) -> Self {
            if let Some(id) = id.into_resettable().into_option() {
                self.conflicts.push(id);
            } else {
                self.conflicts.clear();
            }
            self
        }

        /// Specify arguments or groups that must **not** be present when this group is.
        ///
        /// Exclusion rules function just like [argument exclusion rules], you can name other arguments
        /// or groups that must *not* be present when one of the arguments from this group are used.
        ///
        /// **NOTE:** The names provided may be an argument, or group name
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgGroup, error::ErrorKind, ArgAction};
        /// let result = Command::new("myprog")
        ///     .arg(Arg::new("flag")
        ///         .short('f')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("color")
        ///         .short('c')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("debug")
        ///         .short('d')
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("verb")
        ///         .short('v')
        ///         .action(ArgAction::SetTrue))
        ///     .group(ArgGroup::new("req_flags")
        ///         .args(["flag", "color"])
        ///         .conflicts_with_all(["debug", "verb"]))
        ///     .try_get_matches_from(vec!["myprog", "-c", "-v"]);
        /// // because we used an arg from the group, and the group conflicts with either "-v" or "-d"
        /// // it's an error
        /// assert!(result.is_err());
        /// let err = result.unwrap_err();
        /// assert_eq!(err.kind(), ErrorKind::ArgumentConflict);
        /// ```
        ///
        /// [argument exclusion rules]: crate::Arg::conflicts_with_all()
        #[must_use]
        pub fn conflicts_with_all(mut self, ns: impl IntoIterator<Item = impl Into<Id>>) -> Self {
            for n in ns {
                self = self.conflicts_with(n);
            }
            self
        }
    }

    /// # Reflection
    impl ArgGroup {
        /// Get the name of the group
        #[inline]
        pub fn get_id(&self) -> &Id {
            &self.id
        }

        /// Reports whether [`ArgGroup::required`] is set
        #[inline]
        pub fn is_required_set(&self) -> bool {
            self.required
        }
    }

    impl From<&'_ ArgGroup> for ArgGroup {
        fn from(g: &ArgGroup) -> Self {
            g.clone()
        }
    }

    #[cfg(test)]
    mod test {
        use super::*;

        #[test]
        fn groups() {
            let g = ArgGroup::new("test")
                .arg("a1")
                .arg("a4")
                .args(["a2", "a3"])
                .required(true)
                .conflicts_with("c1")
                .conflicts_with_all(["c2", "c3"])
                .conflicts_with("c4")
                .requires("r1")
                .requires_all(["r2", "r3"])
                .requires("r4");

            let args: Vec<Id> = vec!["a1".into(), "a4".into(), "a2".into(), "a3".into()];
            let reqs: Vec<Id> = vec!["r1".into(), "r2".into(), "r3".into(), "r4".into()];
            let confs: Vec<Id> = vec!["c1".into(), "c2".into(), "c3".into(), "c4".into()];

            assert_eq!(g.args, args);
            assert_eq!(g.requires, reqs);
            assert_eq!(g.conflicts, confs);
        }

        #[test]
        fn test_from() {
            let g = ArgGroup::new("test")
                .arg("a1")
                .arg("a4")
                .args(["a2", "a3"])
                .required(true)
                .conflicts_with("c1")
                .conflicts_with_all(["c2", "c3"])
                .conflicts_with("c4")
                .requires("r1")
                .requires_all(["r2", "r3"])
                .requires("r4");

            let args: Vec<Id> = vec!["a1".into(), "a4".into(), "a2".into(), "a3".into()];
            let reqs: Vec<Id> = vec!["r1".into(), "r2".into(), "r3".into(), "r4".into()];
            let confs: Vec<Id> = vec!["c1".into(), "c2".into(), "c3".into(), "c4".into()];

            let g2 = ArgGroup::from(&g);
            assert_eq!(g2.args, args);
            assert_eq!(g2.requires, reqs);
            assert_eq!(g2.conflicts, confs);
        }

        // This test will *fail to compile* if ArgGroup is not Send + Sync
        #[test]
        fn arg_group_send_sync() {
            fn foo<T: Send + Sync>(_: T) {}
            foo(ArgGroup::new("test"))
        }

        #[test]
        fn arg_group_expose_is_multiple_helper() {
            let args: Vec<Id> = vec!["a1".into(), "a4".into()];

            let mut grp_multiple = ArgGroup::new("test_multiple").args(&args).multiple(true);
            assert!(grp_multiple.is_multiple());

            let mut grp_not_multiple = ArgGroup::new("test_multiple").args(&args).multiple(false);
            assert!(!grp_not_multiple.is_multiple());
        }

        #[test]
        fn arg_group_expose_get_args_helper() {
            let args: Vec<Id> = vec!["a1".into(), "a4".into()];
            let grp = ArgGroup::new("program").args(&args);

            for (pos, arg) in grp.get_args().enumerate() {
                assert_eq!(*arg, args[pos]);
            }
        }
    }