Ruby 2.4 no exception for objects converted to IPAddr

Sushant Mittal

By Sushant Mittal

on June 21, 2017

This blog is part of our  Ruby 2.4 series.

In Ruby, IPAddr#== method is used to check whether two IP addresses are equal or not. Ruby also has IPAddr#<=> method which is used to compare two IP addresses.

In Ruby 2.3, behavior of these methods was inconsistent. Let's see an example.

1
2# Ruby 2.3
3
4>> IPAddr.new("1.2.1.3") == "Some ip address"
5=> IPAddr::InvalidAddressError: invalid address

But if the first argument is invalid IP address and second is valid IP address, then it would return false.

1
2# Ruby 2.3
3
4>> "Some ip address" == IPAddr.new("1.2.1.3")
5=> false
6

The <=> method would raise exception in both the cases.

1
2# Ruby 2.3
3
4>> "Some ip address" <=> IPAddr.new("1.2.1.3")
5=> IPAddr::InvalidAddressError: invalid address
6
7>> IPAddr.new("1.2.1.3") <=> "Some ip address"
8=> IPAddr::InvalidAddressError: invalid address
9

In Ruby 2.4, this issue is fixed for both the methods to return the result without raising exception, if the objects being compared can't be converted to an IPAddr object.

1
2# Ruby 2.4
3
4>> IPAddr.new("1.2.1.3") == "Some ip address"
5=> false
6
7>> "Some ip address" == IPAddr.new("1.2.1.3")
8=> false
9
10>> IPAddr.new("1.2.1.3") <=> "Some ip address"
11=> nil
12
13>> "Some ip address" <=> IPAddr.new("1.2.1.3")
14=> nil

This might cause some backward compatibility if our code is expecting the exception which is no longer raised in Ruby 2.4.

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