Make Resolve(nil) return map of top-level objects, fixes #20

[sameer]

I added a mapping to the top-level objects where appropriate. Please let me know if I missed something.

[magik6k]

A test would be nice

[sameer]

• Updated to work with the date format changes
• Added tests for all the resolve methods to make sure they returns something valid
  • Discovered commit.Sig.Text dereferences a null pointer when there's no signature which I've fixed in this PR too

[sameer]

Hello, has this issue been resolved?

[rvagg]

Sorry @sameer! I closed this because we're getting up on 2 years now and I made the (obviously false) assumption that it was stale. We've done quite a bit of work in #46 that will soon be merged and it's a big divergence from the current codebase.

The new code uses https://github.com/ipld/go-ipld-prime as its basis, which will be used for traversal and node resolution, which removes resolve concerns from the codecs themselves. I believe that resolving to the root of one of these nodes should just give you the node as it is, like this PR was trying to do.

I've added some tests in go-ipfs that I think demonstrate that resolution is working as intended by this PR now that we have all the data in ipld-prime form: ipfs/kubo@bbc722b#diff-376e0b27fef811d85269a61a2b09648655b95dfd0a9136adf278061dbb23a1da (part of ipfs/kubo#7976). Let me know if you think there's something amiss.

[sameer]

Was just curious, thanks for the update! 🙂