Subject: Re: [PATCH v5 5/7] refs: use transaction in `refs_create_symref()`

From: Patrick Steinhardt <[email-masked]>
Date: Thu, 2 May 2024 09:47:28 +0200

On Wed, May 01, 2024 at 10:22:27PM +0200, Karthik Nayak wrote:
> From: Karthik Nayak <[email-masked]>
> 
> The `refs_create_symref()` function updates a symref to a given new
> target. To do this, it uses a ref-backend specific function
> `create_symref()`.
> 
> In this previous commit, we introduce symref support in transactions.
> This means we can now use transactions to perform symref updates and not
> have to resort to `create_symref()`. Doing this allows us to remove and

Nit: "not have to" -> "don't have to"

[snip]
> diff --git a/t/t0610-reftable-basics.sh b/t/t0610-reftable-basics.sh
> index 178791e086..9e8d22bcbd 100755
> --- a/t/t0610-reftable-basics.sh
> +++ b/t/t0610-reftable-basics.sh
> @@ -286,7 +286,7 @@ test_expect_success 'ref transaction: creating symbolic ref fails with F/D confl
>  	git init repo &&
>  	test_commit -C repo A &&
>  	cat >expect <<-EOF &&
> -	error: unable to write symref for refs/heads: file/directory conflict
> +	error: ${SQ}refs/heads/main${SQ} exists; cannot create ${SQ}refs/heads${SQ}
>  	EOF
>  	test_must_fail git -C repo symbolic-ref refs/heads refs/heads/foo 2>err &&
>  	test_cmp expect err

Nice. Not only do we have less code to worry about, but the error
message is better, too.

> diff --git a/t/t1416-ref-transaction-hooks.sh b/t/t1416-ref-transaction-hooks.sh
> index 2092488090..4433ac2177 100755
> --- a/t/t1416-ref-transaction-hooks.sh
> +++ b/t/t1416-ref-transaction-hooks.sh
> @@ -134,4 +134,27 @@ test_expect_success 'interleaving hook calls succeed' '
>  	test_cmp expect target-repo.git/actual
>  '
>  
> +test_expect_success 'hook captures git-symbolic-ref updates' '
> +	test_when_finished "rm actual" &&
> +
> +	test_hook reference-transaction <<-\EOF &&
> +		echo "$*" >>actual
> +		while read -r line
> +		do
> +			printf "%s\n" "$line"
> +		done >>actual
> +	EOF
> +
> +	git symbolic-ref refs/heads/symref refs/heads/main &&
> +
> +	cat >expect <<-EOF &&
> +		prepared
> +		$ZERO_OID ref:refs/heads/main refs/heads/symref
> +		committed
> +		$ZERO_OID ref:refs/heads/main refs/heads/symref
> +	EOF

Nit: the contents of the heredoc should be indented one level less.

Patrick