Expressions

# serialization
${{ toJSON(github.event) }}

# comparison
${{ env.foo == 'yes' }}
${{ env.foo == 'yes' && env.bar == 'no' }}

# starts with
startsWith(github.ref, 'refs/tags/')

# contains
${{ contains(github.event.head_commit.message, '[no rel]') }}

# not
${{ ! contains(github.event.head_commit.message, '[no build]') }} # the commit doesn't have a build

# true is steps above have failed
${{ failure() }}

# hash based on files
${{ hashFiles('**/package-lock.json', '**/yarn.lock') }}
${{ hashFiles('**.[jt]s', '**.[jt]sx') }}

# from JSON
# useful for converting string to boolean
fromJSON(needs.check.outputs.package-released)