class RuboCop::Cop::RSpec::BeEql

Check for expectations where ‘be(…)` can replace `eql(…)`.

The ‘be` matcher compares by identity while the `eql` matcher compares using `eql?`. Integers, floats, booleans, symbols, and nil can be compared by identity and therefore the `be` matcher is preferable as it is a more strict test.

@safety

This cop is unsafe because it changes how values are compared.

@example

# bad
expect(foo).to eql(1)
expect(foo).to eql(1.0)
expect(foo).to eql(true)
expect(foo).to eql(false)
expect(foo).to eql(:bar)
expect(foo).to eql(nil)

# good
expect(foo).to be(1)
expect(foo).to be(1.0)
expect(foo).to be(true)
expect(foo).to be(false)
expect(foo).to be(:bar)
expect(foo).to be(nil)

This cop only looks for instances of ‘expect(…).to eql(…)`. We do not check `to_not` or `not_to` since `!eql?` is more strict than `!equal?`. We also do not try to flag `eq` because if `a == b`, and `b` is comparable by identity, `a` is still not necessarily the same type as `b` since the `#==` operator can coerce objects for comparison.