faker-ruby/faker · error · ArgumentError

Size should be specified in format 300x300

Error message

Size should be specified in format 300x300

What it means

Raised by the private Faker::LoremFlickr.build_url (used by image, grayscale_image, pixelated_image, colorized_image) when the size string does not match /\A[0-9]+x[0-9]+\z/ — i.e. anything other than digits, a literal 'x', digits. The URL path needs the width and height as separate segments, so malformed sizes like '300', '300x', '300X300', '300 x 300', or '300.5x200' are rejected.

Source

Thrown at lib/faker/default/lorem_flickr.rb:99

      # @example
      #   Faker::LoremFlickr.image #=> "https://loremflickr.com/red/300/300/all"
      #   Faker::LoremFlickr.image(size: "50x60", color: 'blue') #=> "https://loremflickr.com/blue/50/60/all"
      #   Faker::LoremFlickr.image(size: "50x60", color: 'blue', search_terms: ['sports']) #=> "https://loremflickr.com/blue/50/60/sports"
      #   Faker::LoremFlickr.image(size: "50x60", color: 'blue', search_terms: ['sports', 'fitness']) #=> "https://loremflickr.com/blue/50/60/sports,fitness"
      #   Faker::LoremFlickr.image(size: "50x60", color: 'blue', search_terms: ['sports', 'fitness'], match_all: true) #=> "https://loremflickr.com/blue/50/60/sports,fitness/all"
      #
      # @faker.version 1.9.0
      def colorized_image(size: '300x300', color: 'red', search_terms: ['all'], match_all: false)
        raise ArgumentError, 'Search terms must be specified for colorized images' unless search_terms.any?
        raise ArgumentError, "Supported colorizations are #{SUPPORTED_COLORIZATIONS.join(', ')}" unless SUPPORTED_COLORIZATIONS.include?(color)

        build_url(size, color, search_terms, match_all)
      end

      private

      def build_url(size, format, search_terms, match_all)
        raise ArgumentError, 'Size should be specified in format 300x300' unless size =~ /\A[0-9]+x[0-9]+\z/

        url_parts = ['https://loremflickr.com']
        url_parts << format
        url_parts += size.split('x')
        url_parts << search_terms.compact.join(',') if search_terms.any?
        url_parts << 'all' if match_all
        url_parts.compact.join('/')
      end
    end
  end
end

View on GitHub (pinned to cca4184947)

Solutions

1. Pass size as digits-x-digits, e.g. size: '300x300' or size: "#{width}x#{height}".
2. Normalize before calling: size = "#{width.to_i}x#{height.to_i}" to strip whitespace/nil.
3. Validate with the same regex in the calling layer: size =~ /\A[0-9]+x[0-9]+\z/.

Example fix

# before
Faker::LoremFlickr.image(size: "#{width} x #{height}") # ArgumentError

# after
Faker::LoremFlickr.image(size: "#{width.to_i}x#{height.to_i}")

size = "#{width.to_i}x#{height.to_i}"
raise ArgumentError, 'bad size' unless size =~ /\A[0-9]+x[0-9]+\z/
Faker::LoremFlickr.image(size: size, search_terms: terms)

def valid_loremflickr_size?(size)
  size.is_a?(String) && size.match?(/\A[0-9]+x[0-9]+\z/)
end

begin
  Faker::LoremFlickr.image(size: size)
rescue ArgumentError
  Faker::LoremFlickr.image # default 300x300
end

When it happens

Trigger: Faker::LoremFlickr.image(size: '300') or size: '100*100', size: '50X60' (capital X), size: '50x60 ' (trailing space) raises 'Size should be specified in format 300x300'.

Common situations: Composing size from variables: "#{w}x#{h}" when one side is nil gives '300x'; accepting dimensions from user input or config without normalization; using '×' (Unicode multiplication sign) instead of ASCII 'x'.

Related errors

• Size should be specified in format 300x300
• background_color must be a hex value without '#'
• text_color must be a hex value without '#'
• Search terms must be specified for grayscale images
• Search terms must be specified for pixelated images

AI-assisted analysis of faker-ruby/faker@cca4184947 (2026-08-21). Data as JSON: /api/errors/f6527ef4a327a78d. Report an issue: GitHub.