mod from_bytes {    use crate::immutable::fixture_bytes;    use git_object::{        bstr::ByteSlice,        immutable::{tree::Entry, Tree, TreeIter},        tree,    };    use hex::FromHex;     pub fn hex_to_id(hex: &str) -> [u8; 20] {        <[u8; 20]>::from_hex(hex).expect("40 bytes hex sha")    }     pub fn as_id(id: &[u8; 20]) -> &git_hash::oid {        id.into()    }     #[test]    fn everything() -> Result<(), Box<dyn std::error::Error>> {        assert_eq!(            Tree::from_bytes(&fixture_bytes("tree", "everything.tree"))?,            Tree {                entries: vec![                    Entry {                        mode: tree::EntryMode::BlobExecutable,                        filename: b"exe".as_bstr(),                        oid: as_id(&hex_to_id("e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"))                    },                    Entry {                        mode: tree::EntryMode::Blob,                        filename: b"file".as_bstr(),                        oid: as_id(&hex_to_id("e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"))                    },                    Entry {                        mode: tree::EntryMode::Commit,                        filename: b"grit-submodule".as_bstr(),                        oid: as_id(&hex_to_id("b2d1b5d684bdfda5f922b466cc13d4ce2d635cf8"))                    },                    Entry {                        mode: tree::EntryMode::Tree,                        filename: b"subdir".as_bstr(),                        oid: as_id(&hex_to_id("4d5fcadc293a348e88f777dc0920f11e7d71441c"))                    },                    Entry {                        mode: tree::EntryMode::Link,                        filename: b"symlink".as_bstr(),                        oid: as_id(&hex_to_id("1a010b1c0f081b2e8901d55307a15c29ff30af0e"))                    }                ]            }        );        Ok(())    }     #[test]    fn iter_error_handling() -> Result<(), Box<dyn std::error::Error>> {        let data = fixture_bytes("tree", "everything.tree");        let iter = TreeIter::from_bytes(&data[..data.len() / 2]);        let entries = iter.collect::<Vec<_>>();        assert!(            entries.last().expect("at least one token").is_err(),            "errors are propagated and none is returned from that point on"        );        Ok(())    }     #[test]    fn everything_iter() -> Result<(), Box<dyn std::error::Error>> {        assert_eq!(            TreeIter::from_bytes(&fixture_bytes("tree", "everything.tree")).collect::<Result<Vec<_>, _>>()?,            vec![                Entry {                    mode: tree::EntryMode::BlobExecutable,                    filename: b"exe".as_bstr(),                    oid: as_id(&hex_to_id("e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"))                },                Entry {                    mode: tree::EntryMode::Blob,                    filename: b"file".as_bstr(),                    oid: as_id(&hex_to_id("e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"))                },                Entry {                    mode: tree::EntryMode::Commit,                    filename: b"grit-submodule".as_bstr(),                    oid: as_id(&hex_to_id("b2d1b5d684bdfda5f922b466cc13d4ce2d635cf8"))                },                Entry {                    mode: tree::EntryMode::Tree,                    filename: b"subdir".as_bstr(),                    oid: as_id(&hex_to_id("4d5fcadc293a348e88f777dc0920f11e7d71441c"))                },                Entry {                    mode: tree::EntryMode::Link,                    filename: b"symlink".as_bstr(),                    oid: as_id(&hex_to_id("1a010b1c0f081b2e8901d55307a15c29ff30af0e"))                }            ]        );        Ok(())    }     #[test]    fn maybe_special() -> Result<(), Box<dyn std::error::Error>> {        assert_eq!(            Tree::from_bytes(&fixture_bytes("tree", "maybe-special.tree"))?                .entries                .len(),            160        );        Ok(())    }     #[test]    fn definitely_special() -> Result<(), Box<dyn std::error::Error>> {        assert_eq!(            Tree::from_bytes(&fixture_bytes("tree", "definitely-special.tree"))?                .entries                .len(),            19        );        Ok(())    }}