pypi.rb

# typed: false
# frozen_string_literal: true

module Homebrew
  module Livecheck
    module Strategy
      # The {Pypi} strategy identifies versions of software at pypi.org by
      # checking project pages for archive files.
      #
      # PyPI URLs have a standard format but the hexadecimal text between
      # `/packages/` and the filename varies:
      #
      # * `https://files.pythonhosted.org/packages/<hex>/<hex>/<long_hex>/example-1.2.3.tar.gz`
      #
      # As such, the default regex only targets the filename at the end of the
      # URL.
      #
      # @api public
      class Pypi
        extend T::Sig

        NICE_NAME = "PyPI"

        # The `Regexp` used to extract the package name and suffix (e.g., file
        # extension) from the URL basename.
        FILENAME_REGEX = /
          (?<package_name>.+)- # The package name followed by a hyphen
          .*? # The version string
          (?<suffix>\.tar\.[a-z0-9]+|\.[a-z0-9]+)$ # Filename extension
        /ix.freeze

        # The `Regexp` used to determine if the strategy applies to the URL.
        URL_MATCH_REGEX = %r{
          ^https?://files\.pythonhosted\.org
          /packages
          (?:/[^/]+)+ # The hexadecimal paths before the filename
          /#{FILENAME_REGEX.source.strip} # The filename
        }ix.freeze

        # Whether the strategy can be applied to the provided URL.
        #
        # @param url [String] the URL to match against
        # @return [Boolean]
        def self.match?(url)
          URL_MATCH_REGEX.match?(url)
        end

        # Generates a URL and regex (if one isn't provided) and passes them
        # to {PageMatch.find_versions} to identify versions in the content.
        #
        # @param url [String] the URL of the content to check
        # @param regex [Regexp] a regex used for matching versions in content
        # @return [Hash]
        sig {
          params(
            url:   String,
            regex: T.nilable(Regexp),
            cask:  T.nilable(Cask::Cask),
            block: T.nilable(
              T.proc.params(arg0: String, arg1: Regexp).returns(T.any(String, T::Array[String], NilClass)),
            ),
          ).returns(T::Hash[Symbol, T.untyped])
        }
        def self.find_versions(url, regex, cask: nil, &block)
          match = File.basename(url).match(FILENAME_REGEX)

          # Use `\.t` instead of specific tarball extensions (e.g. .tar.gz)
          suffix = match[:suffix].sub(/\.t(?:ar\..+|[a-z0-9]+)$/i, "\.t")

          # It's not technically necessary to have the `#files` fragment at the
          # end of the URL but it makes the debug output a bit more useful.
          page_url = "https://pypi.org/project/#{match[:package_name].gsub(/%20|_/, "-")}/#files"

          # Example regex: `%r{href=.*?/packages.*?/example[._-]v?(\d+(?:\.\d+)*(?:[._-]post\d+)?)\.t}i`
          re_package_name = Regexp.escape(match[:package_name])
          re_suffix = Regexp.escape(suffix)
          regex ||= %r{href=.*?/packages.*?/#{re_package_name}[._-]v?(\d+(?:\.\d+)*(?:[._-]post\d+)?)#{re_suffix}}i

          PageMatch.find_versions(page_url, regex, cask: cask, &block)
        end
      end
    end
  end
end