It would be nice to be able to use snapshot testing and not have to
parse the output of `jj op log`. This patch lets us do that by
providing a new environment variable and config for overriding the
timestamps. Unlike `operation.hostname` and `operation.username`,
these are only meant for tests.
This makes the tests more hermetic, even though I don't think the
default values (taken from `whoami`) can break any tests (then we
would have already seen them break). Now we just need to make the
operation log's timestamps predictable and then we can start using
operation IDs in snapshot tests.
In the test case `test_branch_mutually_exclusive_actions`, we weren't actually testing anything useful, because the interface has since changed to use subcommands instead of options. The test has been deleted in this commit, and `TestEnvironment::jj_cmd_cli_error` has been changed to return a `#[must_use]` `String` representing stderr. I also added `#[must_use]` to `TestEnvironment::jj_cmd_failure` while I was here.
The `testutils` module should ideally not be part of the library
dependencies. Since they're used by the integration tests (and the CLI
tests), we need to move them to a separate crate to achieve that.
Mercurial's test runner does something like this.
I considered replacing `\` by `/` everywhere, but we use `\` in
graph-log output quite frequently, so it doesn't seem worth it.
libgit2 by default will respect config files present on a user's
machine---in particular, when creating a new repo, it will read
`init.defaultBranch` to determine what the name of the default branch
should be. This makes the tests non-hermetic, so disable that feature.
On my machine, `init.defaultBranch` is set in system config. Without
this patch, `test_git_colocated` and
`test_git_colocated_rebase_on_import` fail, but with this patch, they
pass.
We didn't have any testing of exit codes on failure, other than
checking that they were not 0. This patch changes that so we always
check. Since we have the special exit code 2 (set by `clap`) for
incorrect command line, I've replaced some testing of error messages
by testing of just the exit code.
As part of this, I also fixed `jj branch --allow-backwards` to
actually require `-r` (it didn't before because having a default value
means the argument is considered always provided).
It's annoying especially for tests to not be able to append to a
config file without knowing the contents (as you have to do with
TOML). Let's read all files in a directory if `$JJ_CONFIG` points to a
directory. Mercurial does that for its `$HGRCPATH` variable.
Sometimes it's useful to have an environment variable set for all
commands in a test. This patch lets you do that by adding environment
variables to the `TestEnvironment` itself. These will then be set on
all subsequent commands.
