Re: [PATCH 2/8] p5400: add perf tests for git-receive-pack(1)

On Wed, May 19, 2021 at 09:13:27PM +0200, Patrick Steinhardt wrote:

This (and the other array manipulation below) is a bash-ism. Presumably you've got TEST_SHELL_PATH pointed at bash. Without that, on a system where /bin/sh is dash, the script chokes here.

For your purposes here, I think you can get by with just a single string with newlines in it. Or even a file (see below).

This inverts the double- and single- quotes from our usual style. So if $repo is "foo", you are creating a string that has:

  test_must_fail git push --force 'foo' ...

in it, and then the test harness will eval that string. That will fail if $repo itself contains a single quote. Pretty unlikely, but I think it contains the absolute path.

The usual style is:

  test_expect_success "setup $name $desc" '
	test_must_fail git push --force "$repo" "$ref" \
	...etc...
  '

where the variables are dereferenced inside the eval'd snippet. So no quoting is necessary, no matter what's in the variables.

Likewise here, but note that test_perf is tricky! It runs the snippet in a sub-process. You have to export $repo to make it visible (you can use test_export, but you don't need to; there's some discussing in t/perf/README).

These process substitutions are also bash-isms. I guess you're trying to avoid putting the while on the right-hand side of a pipe like:

  printf "%s\n" ... |
  while read ...

which is good, because they set variables and those values don't reliably make it out of the pipeline. If you stick the contents of $refs into a file, then you can just do:

  while read ...
  do
     ...
  done <ref-descs

For the outer one, a here-doc is probably a bit simpler:

  while read ...
  do
     ...
  done <<-EOF
  clone $TARGET_REPO_CLONE
  extrarefs $TARGET_REPO_REFS
  empty $TARGET_REPO_EMPTY
  EOF

-Peff