Class: Browserctl::Snapshot::RefDeriver

Inherits:
Object
  • Object
show all
Defined in:
lib/browserctl/snapshot/ref.rb

Overview

Derives a stable element ref from semantic + structural signals.

The same DOM element should produce the same ref across two snapshots of the same page. Inputs to the hash are:

- role (explicit @role, else implicit ARIA role from tag)
- accessible name (aria-label || text || placeholder || alt)
- tag
- parent path (chain of ancestor tag names up to <html>)

Collisions within a single snapshot are disambiguated by the caller via ‘disambiguate(ref, taken)` — the deriver itself is pure.

Constant Summary collapse

IMPLICIT_ROLE = 
{
  "a" => "link", "button" => "button", "input" => "textbox",
  "select" => "combobox", "textarea" => "textbox"
}.freeze
HASH_LEN = 
7

Instance Method Summary collapse

Instance Method Details

#derive(node) ⇒ Object 



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# File 'lib/browserctl/snapshot/ref.rb', line 26

def derive(node)
  signal = [role(node), accessible_name(node), node.name, parent_path(node)].join("|")
  "e#{Digest::SHA256.hexdigest(signal)[0, HASH_LEN]}"
end

#disambiguate(ref, taken) ⇒ Object

Given a candidate ref and a set of already-taken refs in the current snapshot, return a unique ref. Adds ‘-2`, `-3`, … as needed.



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# File 'lib/browserctl/snapshot/ref.rb', line 33

def disambiguate(ref, taken)
  return ref unless taken.include?(ref)

  n = 2
  n += 1 while taken.include?("#{ref}-#{n}")
  "#{ref}-#{n}"
end