From: Derrick Stolee <stolee@gmail.com>
Date: Tue, 10 Dec 2019 01:49:36 GMT
Subject: Re: [PATCH v2 8/8] test-lib: clear watchman watches at test completion
Message-ID: <bfa73fab-ce2c-a05e-3568-cd406dd5c31f@gmail.com>
In-Reply-To: <xmqqwob5ru27.fsf@gitster-ct.c.googlers.com>

On 12/9/2019 5:52 PM, Junio C Hamano wrote:
> "Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>> +test_clear_watchman () {
>> +	if test -n "$GIT_TEST_FSMONITOR"
>> +	then
>> +		watchman watch-list |
>> +			grep "$TRASH_DIRECTORY" |
>> +			sed "s/\",//g" |
>> +			sed "s/\"//g" >repo-list
> 
> Whoa, this is scary.  "$TRASH_DIRECTORY" comes from $(pwd) and the
> leading part of it can have arbitrary garbage like "[a-z]*" that may
> match paths "watchman watch-list" may emit that does not have
> anything to do with the temporary directory used by this test.

Hm. That is a good point. Can we assume that our version of grep has
a "-F" or "--fixed-strings" option? ([1] seems to say that "-F" would
work.)

[1] https://www.gnu.org/savannah-checkouts/gnu/grep/manual/grep.html#index-grep-programs

> What are these stripping of ", and " about?  Could you tell readers
> how a typical output from the program we are reading from looks like
> perhaps in the log message or in-code comment around here?

Watchman outputs its list of paths in JSON format. Luckily, it formats
the output so the path lines are on separate lines, each quoted.

For example:

{
	"version": "4.9.0",
	"roots": [
		"<path1>",
		"<path2>",
		"<path3>"
	]
}

Thanks,
-Stolee