Coverage Report

Created: 2025-08-26 07:04

/rust/registry/src/index.crates.io-6f17d22bba15001f/uuid-1.18.0/src/error.rs
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use crate::std::fmt;
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/// A general error that can occur when working with UUIDs.
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#[derive(Clone, Debug, Eq, Hash, PartialEq)]
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pub struct Error(pub(crate) ErrorKind);
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#[derive(Clone, Debug, Eq, Hash, PartialEq)]
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pub(crate) enum ErrorKind {
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    /// Invalid character in the [`Uuid`] string.
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    ///
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    /// [`Uuid`]: ../struct.Uuid.html
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    ParseChar { character: char, index: usize },
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    /// A simple [`Uuid`] didn't contain 32 characters.
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    ///
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    /// [`Uuid`]: ../struct.Uuid.html
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    ParseSimpleLength { len: usize },
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    /// A byte array didn't contain 16 bytes
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    ParseByteLength { len: usize },
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    /// A hyphenated [`Uuid`] didn't contain 5 groups
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    ///
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    /// [`Uuid`]: ../struct.Uuid.html
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    ParseGroupCount { count: usize },
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    /// A hyphenated [`Uuid`] had a group that wasn't the right length
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    ///
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    /// [`Uuid`]: ../struct.Uuid.html
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    ParseGroupLength {
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        group: usize,
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        len: usize,
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        index: usize,
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    },
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    /// The input was not a valid UTF8 string
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    ParseInvalidUTF8,
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    /// Some other parsing error occurred.
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    ParseOther,
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    /// The UUID is nil.
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    Nil,
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    /// A system time was invalid.
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    #[cfg(feature = "std")]
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    InvalidSystemTime(&'static str),
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}
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/// A string that is guaranteed to fail to parse to a [`Uuid`].
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///
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/// This type acts as a lightweight error indicator, suggesting
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/// that the string cannot be parsed but offering no error
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/// details. To get details, use `InvalidUuid::into_err`.
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///
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/// [`Uuid`]: ../struct.Uuid.html
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#[derive(Clone, Debug, Eq, Hash, PartialEq)]
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pub struct InvalidUuid<'a>(pub(crate) &'a [u8]);
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impl<'a> InvalidUuid<'a> {
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    /// Converts the lightweight error type into detailed diagnostics.
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    pub fn into_err(self) -> Error {
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        // Check whether or not the input was ever actually a valid UTF8 string
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        let input_str = match std::str::from_utf8(self.0) {
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            Ok(s) => s,
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            Err(_) => return Error(ErrorKind::ParseInvalidUTF8),
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        };
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        let (uuid_str, offset, simple) = match input_str.as_bytes() {
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            [b'{', s @ .., b'}'] => (s, 1, false),
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            [b'u', b'r', b'n', b':', b'u', b'u', b'i', b'd', b':', s @ ..] => {
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                (s, "urn:uuid:".len(), false)
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            }
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            s => (s, 0, true),
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        };
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        let mut hyphen_count = 0;
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        let mut group_bounds = [0; 4];
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        // SAFETY: the byte array came from a valid utf8 string,
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        // and is aligned along char boundaries.
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        let uuid_str = unsafe { std::str::from_utf8_unchecked(uuid_str) };
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3.10k
        for (index, character) in uuid_str.char_indices() {
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            let byte = character as u8;
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            if character as u32 - byte as u32 > 0 {
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                // Multibyte char
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                return Error(ErrorKind::ParseChar {
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                    character,
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                    index: index + offset + 1,
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                });
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            } else if byte == b'-' {
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                // While we search, also count group breaks
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                if hyphen_count < 4 {
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                    group_bounds[hyphen_count] = index;
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                }
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                hyphen_count += 1;
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            } else if !byte.is_ascii_hexdigit() {
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                // Non-hex char
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                return Error(ErrorKind::ParseChar {
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                    character: byte as char,
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                    index: index + offset + 1,
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                });
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            }
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        }
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        if hyphen_count == 0 && simple {
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            // This means that we tried and failed to parse a simple uuid.
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            // Since we verified that all the characters are valid, this means
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            // that it MUST have an invalid length.
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            Error(ErrorKind::ParseSimpleLength {
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                len: input_str.len(),
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            })
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        } else if hyphen_count != 4 {
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            // We tried to parse a hyphenated variant, but there weren't
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            // 5 groups (4 hyphen splits).
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            Error(ErrorKind::ParseGroupCount {
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                count: hyphen_count + 1,
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            })
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        } else {
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            // There are 5 groups, one of them has an incorrect length
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            const BLOCK_STARTS: [usize; 5] = [0, 9, 14, 19, 24];
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            for i in 0..4 {
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                if group_bounds[i] != BLOCK_STARTS[i + 1] - 1 {
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                    return Error(ErrorKind::ParseGroupLength {
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                        group: i,
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                        len: group_bounds[i] - BLOCK_STARTS[i],
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                        index: offset + BLOCK_STARTS[i] + 1,
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                    });
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                }
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            }
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            // The last group must be too long
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            Error(ErrorKind::ParseGroupLength {
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                group: 4,
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                len: input_str.len() - BLOCK_STARTS[4],
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                index: offset + BLOCK_STARTS[4] + 1,
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            })
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        }
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    }
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}
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// NOTE: This impl is part of the public API. Breaking changes to it should be carefully considered
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impl fmt::Display for Error {
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    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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        match self.0 {
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            ErrorKind::ParseChar {
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                character, index, ..
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            } => {
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                write!(f, "invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-fA-F-], found `{}` at {}", character, index)
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            }
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            ErrorKind::ParseSimpleLength { len } => {
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                write!(
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                    f,
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                    "invalid length: expected length 32 for simple format, found {}",
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                    len
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                )
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            }
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            ErrorKind::ParseByteLength { len } => {
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                write!(f, "invalid length: expected 16 bytes, found {}", len)
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            }
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            ErrorKind::ParseGroupCount { count } => {
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                write!(f, "invalid group count: expected 5, found {}", count)
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            }
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            ErrorKind::ParseGroupLength { group, len, .. } => {
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                let expected = [8, 4, 4, 4, 12][group];
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                write!(
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                    f,
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                    "invalid group length in group {}: expected {}, found {}",
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                    group, expected, len
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                )
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            }
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            ErrorKind::ParseInvalidUTF8 => write!(f, "non-UTF8 input"),
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            ErrorKind::Nil => write!(f, "the UUID is nil"),
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            ErrorKind::ParseOther => write!(f, "failed to parse a UUID"),
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            #[cfg(feature = "std")]
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            ErrorKind::InvalidSystemTime(ref e) => write!(f, "the system timestamp is invalid: {e}"),
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        }
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    }
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}
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#[cfg(feature = "std")]
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mod std_support {
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    use super::*;
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    use crate::std::error;
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    impl error::Error for Error { }
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}