Bug #17017
Updated by sambostock (Sam Bostock) over 4 years ago
While continuing to add edge cases to [`Range#minmax` specs](https://github.com/ruby/spec/pull/777), I discovered the following bug:
```ruby
(1..3.1).to_a == [1, 2, 3] # As expected
(1..3.1).to_a.max == 3 # As expected
(1..3.1).to_a.minmax == [1, 3] # As expected
(1..3.1).max == 3.1 # Should be 3, as above
(1..3.1).minmax == [1, 3.1] # Should be [1, 3], as above
```
One way to detect this scenario might be to do (whatever the C equivalent is of)
```ruby
range_end.is_a?(Numeric) // Is this a numeric range?
&& (range_end - range_begin).modulo(1) == 0 // Can we reach the range_end using the standard step size (1)
```
As for how to handle it, a couple options come to mind:
- We could error out and do something similar to what we do for exclusive ranges
```ruby
raise TypeError, 'cannot exclude non Integer end value'
```
- We might be able to calculate the range end by doing something like
```ruby
num_steps = (range_end / range_beg).to_i - 1 # one fewer steps than would exceed the range_end
max = range_beg + num_steps # take that many steps all at once
```
- We could delegate to `super` and enumerate the range to find the max
```ruby
super
```
- We could update the documentation to define the max for this case as the `range_end`, similarly to how the documentation for `include?` says it behaves like `cover?` for numeric ranges.