Add serde support to Blob type

[thomas-k-cameron]

Motivation and Context

This is a child PR of #2616

The changes that this PR introduces is same as the ones that were merged to unstable-serde-support branch before.

Initially, we tried to make commit to unstable-serde-support branch and merge changes one by one in small PRs. However, in order to make it up to date with the main branch, we would need to go through a large PR of over 700 files.

Thus, I decided to create individual PRs that commits directly to main branch.

Description

• Implements serde support to Blob

Testing

• Test checks whether the serialized/de-serialized data matches with the expected value

Checklist

NA

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[rcoh]

what about refactoring this into a module so you can feature gate it once?

[thomas-k-cameron]

Gotcha.

[thomas-k-cameron]

By the way, why do you have both base64 and base64-simd?

[jjant]

We should only be using base64-simd, I think. base64 is there for this bench comparing base64 to base64-simd.

[rcoh]

implementation looks fine, would be nice to clean up the feature gating a little bit.

Side note—it would be good to add a test to aws-smithy-types additional ci to verify these other deps don't end up in the tree when the cfg gate isn't enabled

[thomas-k-cameron]

implementation looks fine, would be nice to clean up the feature gating a little bit.

Side note—it would be good to add a test to aws-smithy-types additional ci to verify these other deps don't end up in the tree when the cfg gate isn't enabled

Thank you for the suggestion.

You don't really have a way to check whether a struct implements a trait on runtime.
So I think you can't really do this.

Maybe check if you can compile when the features are not enabled?

Let me think about it for a bit.

[thomas-k-cameron]

I added a test that checks whether the traits are properly feature gated by checking whether compilation would succeed.

It tries to compile these pieces of code.

fn main() {
    serde_json::to_string(&ReplaceDataType::default());
}

fn main() {
    let dt: Result<ReplaceDataType, _> = serde_json::from_str("some_str");
}

If cargo check doesn't work, than that means that traits are properly feature gated.

[thomas-k-cameron]

I refactor the code.
It should be lot more readable.

[rcoh]

although very clever, I think we can do something much simpler by adding something like adding:

cargo tree -e no-dev | grep serde to the additional-ci script in this directory

[thomas-k-cameron]

That's sounds simpler.
I updated.

Let me know if I didn't understand you correctly.

[thomas-k-cameron]

I added these code to the script.

# checks whether the features are properly feature-gated
res=$(cargo tree -e no-dev | grep serde) 
if [ "$res" != "" ]; then
    exit 1
fi

[thomas-k-cameron]

OK, I didn't know that grep gives you an error when it can't find a match.

I fixed it up

[thomas-k-cameron]

It should be working now.

[jdisanti]

Looks good. Just some minor suggestions.

[jdisanti]

Thank you for the contribution! ❤️