Bug in StringLiteralsInInterpolation

[bquorning]

$ cat foo.rb
"foo" \
  "bar"

$ bin/rubocop --only StringLiteralsInInterpolation -- foo.rb
Inspecting 1 file
C

Offenses:

foo.rb:1:1: C: Prefer single-quoted strings inside interpolations.
"foo" \
^^^^^
foo.rb:2:3: C: Prefer single-quoted strings inside interpolations.
  "bar"
  ^^^^^

1 file inspected, 2 offenses detected

$ bin/rubocop --version
0.27.0

Since there isn’t any interpolation into the given string, this looks like a bug.

[jonas054]

Confirmed. That's a bug. I'll fix it.

[bquorning]

Confirmed: this cop seems to work fine now. 🍰 thanks!

[e2]

Same topic, so I'm posting here:

Tested on: @be1f42030fce (master)

This works:

foo "#{'bax'}"

... but this doesn't:

foo " #{'bax'}"

(The space causes the problem.)

a.rb:1:9: C: Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.
foo " #{'bax'}"
        ^^^^^

[jonas054]

@e2 I have not been able to reproduce your problem. The message from rubocop indicates that you have configured with

StringLiteralsInInterpolation:
  EnforcedStyle: double_quotes

so both your examples should be reported as violations. Please double-check by putting both examples in the same file and see what you get. If there is a problem, open a new issue.

[e2]

Sorry, I should have provided everything to reproduce the problem.

Here's a script:

#!/bin/sh

url="https://raw.githubusercontent.com/thoughtbot/hound/master/config/style_guides/ruby.yml"
dir="./interpolation_test"
rev="be1f42030fce726da1689335ce3005cd508184f7"

mkdir -p "${dir}"
cd "${dir}"

[ -e ruby.yml ] || wget -O .rubocop.yml "${url}"

[ -e Gemfile ] || echo "gem 'rubocop', github: 'bbatsov/rubocop', ref: '${rev}'" > Gemfile
bundle install --quiet
bundle show rubocop

rm -f foo.rb
cat > foo.rb <<EOS
foo "#{bar}#{'all'}"
foo "#{bar} #{'all'}"
EOS

bundle exec rubocop foo.rb

Expected: 2 errors, regardless of what they are
Got: 1 error (on line 2 - the one with the space)

[vinagrito]

Just wondering, what about:
:"#{some_str.gsub('/', '_')}_some_other_string" - Not working
while this:
"#{some_str.gsub('/', '_')}_some_other_string".to_sym - Does work

[jonas054]

@vinagrito Did you mean, why doesn't RuboCop report the single quotes in the first example if the preference is double_quotes for StringLiteralsInInterpolation? It's because that's a symbol literal. The second example is a string literal.

It looks like this cop, and some others that deal with interpolation, miss the symbol literal case.

[vinagrito]

@jonas054 gotcha