fn test_operations()

in mdb_shard/src/set_operations.rs [478:536]
44 lines of code
1 McCabe index (conditional complexity)

    fn test_operations(mem_shard_1: &MDBInMemoryShard, mem_shard_2: &MDBInMemoryShard) -> Result<()> {
        let disk_shard_1 = convert_to_file(mem_shard_1)?;
        let disk_shard_2 = convert_to_file(mem_shard_2)?;

        verify_mdb_shards_match(mem_shard_1, Cursor::new(&disk_shard_1))?;
        verify_mdb_shards_match(mem_shard_2, Cursor::new(&disk_shard_2))?;

        // Now write these out to disk to verify them
        let tmp_dir = TempDir::with_prefix("gitxet_shard_set_test")?;

        let shard_path_1 = tmp_dir.path().join("shard_1.mdb");
        let shard_path_2 = tmp_dir.path().join("shard_2.mdb");

        std::fs::OpenOptions::new()
            .write(true)
            .create(true)
            .truncate(true)
            .open(&shard_path_1)?
            .write_all(&disk_shard_1[..])?;

        std::fs::OpenOptions::new()
            .write(true)
            .create(true)
            .truncate(true)
            .open(&shard_path_2)?
            .write_all(&disk_shard_2[..])?;

        let mut r1 = Cursor::new(&disk_shard_1);
        let s1 = MDBShardInfo::load_from_reader(&mut r1)?;

        let mut r2 = Cursor::new(&disk_shard_2);
        let s2 = MDBShardInfo::load_from_reader(&mut r2)?;

        let mem_union = mem_shard_1.union(mem_shard_2)?;
        let mut shard_union = Vec::<u8>::new();
        shard_set_union(&s1, &mut r1, &s2, &mut r2, &mut shard_union)?;
        verify_mdb_shards_match(&mem_union, Cursor::new(&shard_union))?;

        let disk_union_path = tmp_dir.path().join("shard_union.mdb");
        let (disk_union_hash, _) = shard_file_union(&shard_path_1, &shard_path_2, &disk_union_path)?;

        let mut disk_union_reader = BufReader::new(File::open(&disk_union_path)?);
        verify_mdb_shards_match(&mem_union, &mut disk_union_reader)?;
        assert_eq!(disk_union_hash, compute_data_hash(&shard_union[..]));

        let mem_difference = mem_shard_1.difference(mem_shard_2)?;
        let mut shard_difference = Vec::<u8>::new();
        shard_set_difference(&s1, &mut r1, &s2, &mut r2, &mut shard_difference)?;
        verify_mdb_shards_match(&mem_difference, Cursor::new(&shard_difference))?;

        let disk_difference_path = tmp_dir.path().join("shard_difference.mdb");
        let (disk_difference_hash, _) = shard_file_difference(&shard_path_1, &shard_path_2, &disk_difference_path)?;

        let mut disk_difference_reader = BufReader::new(File::open(&disk_difference_path)?);
        verify_mdb_shards_match(&mem_difference, &mut disk_difference_reader)?;
        assert_eq!(disk_difference_hash, compute_data_hash(&shard_difference[..]));

        Ok(())
    }