This updates demos to the point where they can run without
warnings. Some of them become less clear, this is addressed
(where I noticed it) in follow-up commits.
Fixes#3209
`jj | head` exits with non-zero code since `head` breaks the
pipe. Also, removed `--color=always` from that command as it
will shortly become unnecessary.
Previosly, this caused the script to stop since it's run with
`set -o pipefail`.
Also, the operation id recovery code stopped working. We
can use `jj debug operation` for this purpose now.
I think it's clearer if only the actual demos started with `demo_`,
so I renamed `demo_helpers.sh` to just `helpers.sh`.
`demo_resolve_conflict.sh` should match `resolve_conflicts.png` (with an s).
This follows up on 5c703aeb0397b560a383bdd57a87235834074b64.
The only reason for this change is that, subjectively, the result looks better to me. I'm not sure why, but I couldn't get used to the old symbol in spite of its seeming reasonableness. It felt really bold and heavy.
If people agree, we can wait until we need to update the screenshots for some other reason before merging this. Sorry I didn't figure this out while the discussion about the referenced commit was going on.
I'm not 100% certain how many fonts support each symbol. Please try it out and let me know if it doesn't work for you.
Compare after:

and before:

@joyously found `o` confusing because it's a valid change id prefix. I
don't have much preference, but `●` seems fine. The "ascii",
"ascii-large", and "legacy" graph styles still use "o".
I didn't change `@` since it seems useful to have that match the
symbol used on the CLI. I don't think we want to have users do
something like `jj co ◎-`.
The command grepped for 'o ' and picked the third line. That was meant
to match the graph nodes only, but it also matched the 'jj co master'
line. Let's match only 'o' at the beginning of the line, and throw in
another space for good measure (since that's what we get from the new
default graph style from Sapling).
The demos don't need to be animated - the user wouldn't miss anything
if they skipped to the end. So let's just show the full output so the
user can read through it at their own pace. We could use plain text,
but I think the colors are helpful, so I went with screenshots.
Closes#166.
It can take quite a while to record a demo. This patch adds a `--fast`
flag for reducing delays to a tenth of the usual. You can play the
recording with `asciinema play -s 0.1` to get close-to-normal speed
(except that command delays will be slower). That way you can adjust
timings with shorter round-trips.