Bug #22080: `Integer(obj, exception: false)` raises when `to_str` doesn't return String

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 4.1.0dev (2026-05-23T13:04:55Z master 6c6df00bbc) +PRISM [x86_64-linux]
• Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN

[Earlopain (Earlopain _)]

obj = Object.new
def obj.to_str = 1

Integer(obj, exception: false) # can't convert Object to String (Object#to_str gives Integer) (TypeError)

But returning the wrong type from to_int is fine:

obj = Object.new
def obj.to_int = "1"

Integer(obj, exception: false) # nil

Doc says this (https://docs.ruby-lang.org/en/master/Kernel.html#method-i-Integer):

With exception given as false, an exception of any kind is suppressed and nil is returned.

So it looks like it should not raise in both cases. Or more specifically, try to_i next, since that is what happens when to_int returns the wrong type.

[Earlopain (Earlopain _)]

• Related to Bug #18998: Kernel#Integer does not convert SimpleDelegator object expectly added