Pattern: Missing use of index_with
Issue: -
This rule looks for uses of each_with_object({}) { ... }, map { ... }.to_h, and Hash[map { ... }] that are transforming an enumerable into a hash where the keys are the original elements. Rails provides the index_with method for this purpose.
# bad
[1, 2, 3].each_with_object({}) { |el, h| h[el] = foo(el) }
[1, 2, 3].map { |el| [el, foo(el)] }.to_h
Hash[[1, 2, 3].collect { |el| [el, foo(el)] }]
# good
[1, 2, 3].index_with { |el| foo(el) }