[pbs-devel] [PATCH proxmox-backup v2 2/4] datastore: test DataBlob encode/decode roundtrip

[Lukas Wagner]

On  2024-07-31 11:36, Dominik Csapak wrote:
> so that we can be sure we can decode an encoded blob again
> 
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
> new in v2
>  pbs-datastore/src/data_blob.rs | 66 ++++++++++++++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
> 
> diff --git a/pbs-datastore/src/data_blob.rs b/pbs-datastore/src/data_blob.rs
> index a7a55fb7..8715afef 100644
> --- a/pbs-datastore/src/data_blob.rs
> +++ b/pbs-datastore/src/data_blob.rs
> @@ -562,3 +562,69 @@ impl<'a, 'b> DataChunkBuilder<'a, 'b> {
>          chunk_builder.build()
>      }
>  }
> +
> +#[cfg(test)]
> +mod test {
> +    use pbs_tools::crypt_config::CryptConfig;
> +
> +    use super::DataChunkBuilder;
> +
> +    const TEST_DATA_LEN: usize = 50;
> +
> +    #[test]
> +    fn test_data_blob_builder() {
> +        let mut data = Vec::with_capacity(TEST_DATA_LEN);
> +        for i in 0..TEST_DATA_LEN / 10 {
> +            for _ in 0..10 {
> +                data.push(i as u8);
> +            }
> +        }
> +
> +        // unencrypted, uncompressed
> +        let (chunk, digest) = DataChunkBuilder::new(&data)
> +            .compress(false)
> +            .build()
> +            .expect("could not create unencrypted, uncompressed chunk");
> +
> +        let data_decoded = chunk
> +            .decode(None, Some(&digest))
> +            .expect("cannot decode unencrypted, uncompressed chunk");
> +        assert_eq!(data, data_decoded);
> +
> +        // unencrypted, compressed
> +        let (chunk, digest) = DataChunkBuilder::new(&data)
> +            .compress(true)
> +            .build()
> +            .expect("could not create unencrypted, compressed chunk");
> +
> +        let data_decoded = chunk
> +            .decode(None, Some(&digest))
> +            .expect("cannot decode unencrypted, compressed chunk");
> +        assert_eq!(data, data_decoded);
> +
> +        // encrypted, uncompressed
> +        let crypt_config = CryptConfig::new([9; 32]).expect("could not create crypt config");
> +        let (chunk, digest) = DataChunkBuilder::new(&data)
> +            .compress(false)
> +            .crypt_config(&crypt_config)
> +            .build()
> +            .expect("could not create encrypted, uncompressed chunk");
> +
> +        let data_decoded = chunk
> +            .decode(Some(&crypt_config), Some(&digest))
> +            .expect("cannot decode encrypted, uncompressed chunk");
> +        assert_eq!(data, data_decoded);
> +
> +        // encrypted, compressed
> +        let (chunk, digest) = DataChunkBuilder::new(&data)
> +            .compress(true)
> +            .crypt_config(&crypt_config)
> +            .build()
> +            .expect("could not create encrypted, compressed chunk");
> +
> +        let data_decoded = chunk
> +            .decode(Some(&crypt_config), Some(&digest))
> +            .expect("cannot decode encrypted, compressed chunk");
> +        assert_eq!(data, data_decoded);
> +    }
> +}

IMO it would be nicer to move the (sub) testcases 
(e.g. 'encrypted, compressed', 'encrypted, uncompressed') to individual test cases,
transforming the info from the comments into the test name, for instance:

  #[test]
  fn test_encrypted_uncompressed() { ... }

(the fact that you test the data_blob module is clear from the full test name, which includes
the module prefix - so I think you can drop it from the test name)

IMO that is quite nice when at some point we end up with a failing assertion, because
you see exactly from the name of the failing test what scenario did not work.

What's your take on this?

-- 
- Lukas