//! Minimal CRC-32 (IEEE 802.3 / gzip / PNG polynomial).

//!

//! Used by the variable-font PostScript-name generator to produce the

//! "last resort" hashed suffix described in the OpenType specification's

//! *Generating PostScript names for OpenType Font Variations* section,

//! which calls for the IEEE 802.3 CRC-32. This is not on a hot path —

//! it only runs when a generated PostScript name exceeds 63 characters —

//! so a simple bitwise implementation is preferred over pulling in a

//! dedicated CRC-32 crate.

const POLY: u32 = 0xEDB88320;

    }

#[cfg(test)]

mod tests {

    use super::hash;

    // Reference values from the standard IEEE 802.3 CRC-32 (gzip / PNG).

    #[test]

    fn empty() {

        assert_eq!(hash(b""), 0);

    }

    #[test]

    fn ascii() {

        // "123456789" has the well-known check value 0xCBF43926.

        assert_eq!(hash(b"123456789"), 0xCBF43926);

    }

    #[test]

    fn short() {

        assert_eq!(hash(b"a"), 0xE8B7BE43);

    }

}