Style-NegatedUnless.md

Pattern: Misused unless with negated condition

Issue: -

Description

Checks for uses of unless with a negated condition. Only unless without else are considered. There are three different styles:

• both
• prefix
• postfix

Examples

EnforcedStyle: both (default)

# enforces `if` for `prefix` and `postfix` conditionals

# bad
unless !foo
  bar
end

# good
if foo
  bar
end

# bad
bar unless !foo

# good
bar if foo

EnforcedStyle: prefix

# enforces `if` for just `prefix` conditionals

# bad
unless !foo
  bar
end

# good
if foo
  bar
end

# good
bar unless !foo

EnforcedStyle: postfix

# enforces `if` for just `postfix` conditionals

# bad
bar unless !foo

# good
bar if foo

# good
unless !foo
  bar
end

Configurable attributes

Name	Default value	Configurable values
EnforcedStyle	both	both, prefix, postfix

Further Reading

• RuboCop - Style/NegatedUnless
• https://rubystyle.guide#if-for-negatives