Module: Greenroom::Digest

Defined in:
lib/greenroom/digest.rb

Overview

Turns an observed value into a short, fixed-length digest for a sample event. Never carries the value itself, only evidence that two values did or did not match.

Class Method Summary collapse

Class Method Details

.of(value) ⇒ Object

Value stability is the host's job, via Scientist's own clean block -- this module only shortens whatever that block already produced. The default #inspect can embed an object's memory address, so a host that needs a digest to stay stable across runs must write a clean block rather than rely on this method to normalize the value.

::Digest::SHA256, not SHA256: this module is itself named Digest, so an unqualified Digest::SHA256 would resolve to Greenroom::Digest::SHA256 (itself) under Ruby's lexical scoping, rather than the standard library's ::Digest module.



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# File 'lib/greenroom/digest.rb', line 22

def of(value)
  return nil if value.nil?

  ::Digest::SHA256.hexdigest(value.inspect)
end