Fixtures for testing standard IPLD codecs

This repository contains fixtures for standard IPLD codecs. It is used to verify the correctness, compatibility and limitations of IPLD implementations.


The fixtures directory contains a suite of test data, where each subdirectory comprises an encoded IPLD block in the formats that are supported for that data. A file containing the binary encoded form of that block has the name <CID>.<codec-name>, where the CID is the CIDv1 using a SHA2-256 multihash of the block for that codec. The codec-name is the standard codec name as found in the multicodec table.

Implementations are expected to be able to:

  1. Read and decode the IPLD block from these files
  2. Re-encode the IPLD block using the supported codecs
  3. Compare the CID of the re-encoded block to the expected CID as per the filename for the given codec

Since the block is encoded in different forms, by re-encoding each decoded form into the different codecs, we are able to test the correctness of the decoding as well as the encoding process. Where the CIDs do not match, there has been a problem either in decoding or encoding the data. If the same error occurs for the data loaded from differently encoded blocks, the error is likely to be with the encoding process. If the error only occurs when re-encoding from a single encoded form of the block then the error may be with the decoding process.

Adding fixtures

The _fixtures_src directory contains the source of each of fixtures contained in the fixtures directory. Each file in _fixtures_src contains an encoded form of a block using one of the supported codecs. The name of the file is <fixture-name>.<codec-name>. The js/make-fixtures.js program (run with node js/make-fixtures.js) is used to generate the fixtures in fixtures for each of the source files.

Fixture generation uses the JavaScript stack for generating data, but this is not a requirement. If you would like to add fixtures and would like to create them manually, or add an alternative mechanism for generating fixtures from source then please do so.

Implementations & Codecs


Fixtures are tested against the go-ipld-prime stack:


Fixtures are tested against the js-multiformats stack:

Running tests


Or, in the js directory, run:


Or, in the go directory, run:


Licensed under either of


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

GIPHY App Key not set. Please check settings

Microsoft Says Passwords are Passé