Re: [PATCH 7/7] t: invert `GIT_TEST_WRITE_REV_INDEX`

From: Derrick Stolee <derrickstolee@github.com>
Date: Apr 12, 2023, 17:37 UTC
Message-ID: <c04a0ea4-c107-f8d2-4a53-f6aa9ee934ef@github.com>
In-Reply-To: <ZDXSHal5IBynUTMX@nand.local>

On 4/11/2023 5:33 PM, Taylor Blau wrote:

Show 16 quoted lines

> On Tue, Apr 11, 2023 at 09:51:06AM -0400, Derrick Stolee wrote:
>> On 4/10/2023 6:53 PM, Taylor Blau wrote:
>>> Instead of getting rid of the option, invert its meaning to instead
>>> disable writing ".rev" files, thereby running the test suite in a mode
>>> where the reverse index is generated from scratch.
>>>
>>> This ensures that we are still running and exercising Git's behavior
>>> when forced to generate reverse indexes from scratch.
>>
>> I don't think this is true because you remove the environment
>> variable from the following test.
> 
> This is intentional; I wrote that last sentence ("This ensures...") with
> an implied "[When set], this ensures..." at the beginning of it. IOW, if
> you wanted to run the test suite with primarily in-memory reverse
> indexes, you still could.

I guess I think of "we are still running and exercising" as only being true if it happens during regular CI, not just when someone thinks to try it.

Show 10 quoted lines

> I wasn't quite sure what to do here. On one hand, sticking
> GIT_TEST_NO_WRITE_REV_INDEX=1 here would ensure that the linux-TEST-vars
> test is still exercising the old code.
> 
> Is that desirable? I dunno. On one hand it increases our coverage, but
> on the other hand I've always treated this suite as for experimental
> features, not older ones.
> 
> But I think all things being equal, I'd rather have more CI coverage
> than not, so I'll add it back in. Thanks for a sanity check on this one.

If we think there is value in continuing to test the case without .rev files by default, then adding it in would be good. I think it has some value at least for some time after the transition. We're unlikely to remember to remove it, but having the extra mode in this build is not too much overhead.

We should consider auditing this build just to be sure we want to continue testing these options or if some could be removed in favor of new defaults.

Thanks, -Stolee