This page lists the options for breaking single-line expressions into multiple lines in Ruby.
Developers and teams need to come to their own decisions about which guideline(s) they prefer (preferences below are just my personal choices and I encourage you to disregard them).
# With trailing parens
x = [1, 2, 3].join(
'-'
)
# With leading dot
x = [1, 2, 3]
.join '-'
# With trailing `=`
x =
[1, 2, 3].join '-'
# I'm not a big fan of the following options but its
# absolutely OK if you are, choose what you find
# works best for your situation.
# With trailing dot
x = [1, 2, 3].
join '-'
# With slash
x = [1, 2, 3].join \
'-'
# With leading `=`, requires slash
x \
= [1, 2, 3].join '-'
# With leading parens, requires slash
x = [1, 2, 3].join \
('-')
The last two are not really valid examples. It's not the leading '=' or '(' that continues the line. It's the backslash on the preceding line.