[ruby-core:119515] [Ruby master Bug#20795] Timeout method doesn't check for negative time values

13 Oct 2024

      Issue #20795 has been updated by Eregon (Benoit Daloze).

Could you make a PR to https://github.com/ruby/timeout ? (or if not open an issue there?)

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Bug #20795: Timeout method doesn't check for negative time values
https://bugs.ruby-lang.org/issues/20795#change-110128

* Author: kanakchaudhari12 (kanak chaudhari)
* Status: Open
* ruby -v: 3.1.0
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
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```ruby
require 'timeout'

# Case 1: Negative timeout with quick execution
Timeout.timeout(-5) do
  puts "This should not execute"
end

# Case 2: Negative timeout with sleep
Timeout.timeout(-5) do
  sleep(10)
end

```

Potential issues with current behaviour:

* Inconsistency: The behaviour differs based on the block's content, which may not be immediately apparent 
* Silent failure: The negative timeout is silently ignored, potentially masking logical errors in the calling code.
* Unexpected source of error: one might expect the timeout method to validate its input, rather than relying on methods called within the block to catch invalid time values.

I suggest this change for the consistent behaviour regardless of code-block as well as the clear indication of the source of the error

```ruby
def timeout(sec, klass = nil, message = nil, &block)
  raise ArgumentError, "timeout must be positive" if sec.is_a?(Numeric) && sec < 0
  # ...
end
```

-- 
https://bugs.ruby-lang.org/