    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

    use std::fmt::{self, Display};

    use semver::{Comparator, Op, Version, VersionReq};

    pub trait VersionExt {
        fn is_prerelease(&self) -> bool;

        fn to_exact_req(&self) -> VersionReq;
    }

    impl VersionExt for Version {
        fn is_prerelease(&self) -> bool {
            !self.pre.is_empty()
        }

        fn to_exact_req(&self) -> VersionReq {
            VersionReq {
                comparators: vec![Comparator {
                    op: Op::Exact,
                    major: self.major,
                    minor: Some(self.minor),
                    patch: Some(self.patch),
                    pre: self.pre.clone(),
                }],
            }
        }
    }

    #[derive(PartialEq, Eq, Hash, Clone, Debug)]
    pub enum OptVersionReq {
        Any,
        Req(VersionReq),
        /// The exact locked version and the original version requirement.
        Locked(Version, VersionReq),
        /// The exact requested version and the original version requirement.
        ///
        /// This looks identical to [`OptVersionReq::Locked`] but has a different
        /// meaning, and is used for the `--precise` field of `cargo update`.
        /// See comments in [`OptVersionReq::matches`] for more.
        Precise(Version, VersionReq),
    }

    impl OptVersionReq {
        pub fn exact(version: &Version) -> Self {
            OptVersionReq::Req(version.to_exact_req())
        }

        // Since some registries have allowed crate versions to differ only by build metadata,
        // A query using OptVersionReq::exact return nondeterministic results.
        // So we `lock_to` the exact version were interested in.
        pub fn lock_to_exact(version: &Version) -> Self {
            OptVersionReq::Locked(version.clone(), version.to_exact_req())
        }

        pub fn is_exact(&self) -> bool {
            match self {
                OptVersionReq::Any => false,
                OptVersionReq::Req(req) | OptVersionReq::Precise(_, req) => {
                    req.comparators.len() == 1 && {
                        let cmp = &req.comparators[0];
                        cmp.op == Op::Exact && cmp.minor.is_some() && cmp.patch.is_some()
                    }
                }
                OptVersionReq::Locked(..) => true,
            }
        }

        pub fn lock_to(&mut self, version: &Version) {
            assert!(self.matches(version), "cannot lock {} to {}", self, version);
            use OptVersionReq::*;
            let version = version.clone();
            *self = match self {
                Any => Locked(version, VersionReq::STAR),
                Req(req) | Locked(_, req) | Precise(_, req) => Locked(version, req.clone()),
            };
        }

        /// Makes the requirement precise to the requested version.
        ///
        /// This is used for the `--precise` field of `cargo update`.
        pub fn precise_to(&mut self, version: &Version) {
            use OptVersionReq::*;
            let version = version.clone();
            *self = match self {
                Any => Precise(version, VersionReq::STAR),
                Req(req) | Locked(_, req) | Precise(_, req) => Precise(version, req.clone()),
            };
        }

        pub fn is_precise(&self) -> bool {
            matches!(self, OptVersionReq::Precise(..))
        }

        /// Gets the version to which this req is precise to, if any.
        pub fn precise_version(&self) -> Option<&Version> {
            match self {
                OptVersionReq::Precise(version, _) => Some(version),
                _ => None,
            }
        }

        pub fn is_locked(&self) -> bool {
            matches!(self, OptVersionReq::Locked(..))
        }

        /// Gets the version to which this req is locked, if any.
        pub fn locked_version(&self) -> Option<&Version> {
            match self {
                OptVersionReq::Locked(version, _) => Some(version),
                _ => None,
            }
        }

        pub fn matches(&self, version: &Version) -> bool {
            match self {
                OptVersionReq::Any => true,
                OptVersionReq::Req(req) => req.matches(version),
                OptVersionReq::Locked(v, _) => {
                    // Generally, cargo is of the opinion that semver metadata should be ignored.
                    // If your registry has two versions that only differing metadata you get the bugs you deserve.
                    // We also believe that lock files should ensure reproducibility
                    // and protect against mutations from the registry.
                    // In this circumstance these two goals are in conflict, and we pick reproducibility.
                    // If the lock file tells us that there is a version called `1.0.0+bar` then
                    // we should not silently use `1.0.0+foo` even though they have the same version.
                    v == version
                }
                OptVersionReq::Precise(v, _) => {
                    // This is used for the `--precise` field of cargo update.
                    //
                    // Unfortunately crates.io allowed versions to differ only
                    // by build metadata. This shouldn't be allowed, but since
                    // it is, this will honor it if requested.
                    //
                    // In that context we treat a requirement that does not have
                    // build metadata as allowing any metadata. But, if a requirement
                    // has build metadata, then we only allow it to match the exact
                    // metadata.
                    v.major == version.major
                        && v.minor == version.minor
                        && v.patch == version.patch
                        && v.pre == version.pre
                        && (v.build == version.build || v.build.is_empty())
                }
            }
        }
    }

    impl Display for OptVersionReq {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            match self {
                OptVersionReq::Any => f.write_str("*"),
                OptVersionReq::Req(req)
                | OptVersionReq::Locked(_, req)
                | OptVersionReq::Precise(_, req) => Display::fmt(req, f),
            }
        }
    }

    impl From<VersionReq> for OptVersionReq {
        fn from(req: VersionReq) -> Self {
            OptVersionReq::Req(req)
        }
    }