Class: Fontisan::Validation::Woff2HeaderValidator

Inherits:
Object
  • Object
show all
Defined in:
lib/fontisan/validation/woff2_header_validator.rb

Overview

Woff2HeaderValidator validates the WOFF2 header structure

This validator checks the WOFF2 header for:

  • Valid signature (0x774F4632 ‘wOF2’)

  • Valid flavor (TrueType or CFF)

  • Reserved field is zero

  • File length consistency

  • Valid table count

  • Valid compressed size

  • Metadata offset/length consistency

  • Private data offset/length consistency

Single Responsibility: WOFF2 header validation

Examples:

Validating a WOFF2 header

validator = Woff2HeaderValidator.new(rules)
issues = validator.validate(woff2_font)

Constant Summary collapse

VALID_FLAVORS =

Valid WOFF2 flavors

[
  0x00010000, # TrueType
  0x74727565, # 'true' (TrueType)
  0x4F54544F, # 'OTTO' (CFF/OpenType)
].freeze

Instance Method Summary collapse

Constructor Details

#initialize(rules) ⇒ Woff2HeaderValidator

Initialize WOFF2 header validator

Parameters:

  • rules (Hash) —

    Validation rules configuration



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# File 'lib/fontisan/validation/woff2_header_validator.rb', line 33

def initialize(rules)
  @rules = rules
  @woff2_config = rules["woff2_validation"] || {}
end

Instance Method Details

#validate(woff2_font) ⇒ Array<Hash>

Validate WOFF2 header

Parameters:

  • woff2_font (Woff2Font) —

    The WOFF2 font to validate

Returns:

  • (Array<Hash>) —

    Array of validation issues



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# File 'lib/fontisan/validation/woff2_header_validator.rb', line 42

def validate(woff2_font)
  issues = []

  header = woff2_font.header
  return issues unless header

  # Check signature
  issues.concat(check_signature(header))

  # Check flavor
  issues.concat(check_flavor(header))

  # Check reserved field
  issues.concat(check_reserved_field(header))

  # Check table count
  issues.concat(check_table_count(header, woff2_font))

  # Check compressed size
  issues.concat(check_compressed_size(header))

  # Check metadata consistency
  issues.concat(check_metadata(header))

  # Check private data consistency
  issues.concat(check_private_data(header))

  issues
end