Re: [RFC PATCH v2 2/4] t1510-repo-setup: don't use exact matching on traces

From: Phillip Wood <phillip.wood123@gmail.com>
Date: Apr 23, 2021, 09:59 UTC
Message-ID: <c31c30f0-2613-0a12-1025-6043ef5f2962@gmail.com>
In-Reply-To: <20210423001539.4059524-3-emilyshaffer@google.com>

Hi Emily

On 23/04/2021 01:15, Emily Shaffer wrote:

Show 10 quoted lines

> Tests which interrogate the exact underlying behavior of the code under
> test, instead of checking for the presence of desired side effects or
> calls, are a known testing antipattern. They are flaky as they need to
> be updated every time the underlying implementation changes.
> 
> By using 'grep --fixed-strings --file <expect>' instead, we can check
> for the positive presence of lines we are sure should be happening, and
> ignore any additional things which may be happening around us (for
> example, additional child processes which are occurring unrelated to the
> code under test).

Show 15 quoted lines

> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
>   t/t1510-repo-setup.sh | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/t/t1510-repo-setup.sh b/t/t1510-repo-setup.sh
> index bbfe05b8e4..8bd4f54d03 100755
> --- a/t/t1510-repo-setup.sh
> +++ b/t/t1510-repo-setup.sh
> @@ -63,7 +63,7 @@ test_repo () {
>   		rm -f trace &&
>   		GIT_TRACE_SETUP="$(pwd)/trace" git symbolic-ref HEAD >/dev/null &&
>   		grep '^setup: ' trace >result &&
> -		test_cmp expected result
> +		grep -Ff expected result

If there is more than one line in expected (it's not clear from the limited context if there is) then grep will succeed if any of the lines match rather than requiring all the lines to match as test_cmp does.

Best wishes

Phillip

>   	)
>   }
>   
>