Module: Textus::Builder::IdempotentWrite

Defined in:
lib/textus/builder/pipeline.rb

Overview

Replaces the freshly-stamped timestamp inside ‘new_bytes` with the timestamp pulled from `old_bytes` (same format). Returns the rewritten bytes, or nil if either side lacks a parseable timestamp.

Class Method Summary collapse

Class Method Details

.extract_timestamp(bytes, format) ⇒ Object 



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# File 'lib/textus/builder/pipeline.rb', line 35

def self.extract_timestamp(bytes, format)
  case format
  when "markdown"
    parsed = Entry.for_format("markdown").parse(bytes)
    parsed.dig("_meta", "generated", "at")
  when "json", "yaml"
    parsed = Entry.for_format(format).parse(bytes)
    parsed.dig("_meta", "generated_at")
  else # rubocop:disable Style/EmptyElse
    nil
  end
rescue Textus::BadFrontmatter
  nil
end

.rewrite_with_prior_timestamp(new_bytes:, old_bytes:, format:) ⇒ Object 



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# File 'lib/textus/builder/pipeline.rb', line 26

def self.rewrite_with_prior_timestamp(new_bytes:, old_bytes:, format:)
  prior = extract_timestamp(old_bytes, format)
  fresh = extract_timestamp(new_bytes, format)
  return nil unless prior && fresh
  return new_bytes if prior == fresh

  new_bytes.sub(fresh, prior)
end