actions/checkout@v4
actions/checkout@main
actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab
actions/aws/ec2@main
actions/aws/nested/deep/path@v1
owner/repo/a/b/c@v1.2
./local/action
./
.\win\action
.\
docker://alpine:3.8
docker://gcr.io/my-project/my-image:latest
docker://
Docker://alpine
$/
$/path
$/.github/actions/x
$//a/b
$/foo@v1
$/@v1
$/a@
actions/checkout
actions/checkout@
checkout@v4
/repo@v4
owner/@v4
@v4
a@b@c
a/b@c@d
a/b@
a/b@@
a//b@c
//a/b@c
/a/b@c
a\b@c
a\b\c@v1
a/\b@c
 actions/checkout@v4
actions/checkout@v4 
actions /checkout@v4
a/b @c
a/b@c d
a/b/../c@v1
a/b/./c@v1
a/b/@v1
a/b//@v1
..
../x
.
x
a
a/b
é/è@v1
a/b@é
😀/b@v1
a/b@c/d
a/b@refs/heads/main
a/b@refs/tags/v1
actions/checkout@v4.1.0
a-b/c_d@v1
A/B@V1
owner/repo/.github/workflows/ci.yml@main
./.github/actions/x
./a b
~/x
file:///x
https://github.com/a/b@v1
git@github.com:a/b.git