Trigger 412 ETag mismatch

etag_failure.rb

#!/usr/bin/env ruby

require 'faraday'

URL = 'http://localhost:8983/fedora/rest'

def main
  client = Faraday.new(url: URL)
  create_retreve_update(client)
end

def create_retreve_update(client)
  100.times do |n|
    subject = create(client, content)
    etag = retrieve(client, subject)

    create_subnode(client, "#{subject}/fcr:content", "Foo bar");
    begin
      update(client, subject, etag, new_content(subject))
    rescue => e
      puts "On iteration #{n}:"
      raise e
    end
  end
end

def content
  "<> <http://fedora.info/definitions/v4/rels-ext#hasModel> \"DummyAsset\" .\n"
end

def new_content(subject)
  "<#{subject}> <http://purl.org/dc/terms/title> \"Bar\"^^<http://www.w3.org/2001/XMLSchema#string> .\n"
end

def update(client, subject, etag, new_content)
  resp = client.put subject, new_content do |req|
    req.headers['If-Match'] = etag
    req.headers['Content-Type'] = 'text/turtle'
  end
  raise "Status was #{resp.status} #{resp.body}" unless resp.status == 204
end

def retrieve(client, subject)
  resp = client.get subject do |req|
    req.headers["Prefer"] = "return=representation" 
  end
    
  resp.headers['ETag']
end

def create(client, content)
  resp = client.post("#{URL}/test", content) do |req|
    req.headers['Content-Type'] = 'text/turtle'
  end
  resp.headers['Location']
end

def create_subnode(client, url, content)
  resp = client.post url, content, 'Content-Type' => 'text/plain'
end

main();