Remove homebrew-fork Checksum class and refactor

* perform actual checksum calculation within download.rb
* use an accessor named sha256 instead of sums for checksum data
* migrate checksum-specific exceptions out of homebrew-fork

lib/cask/audit.rb

@@ -13,7 +13,6 @@ class Cask::Audit
   def run!(download = false)
     _check_required_stanzas
     _check_no_string_version_latest
-    _check_checksums
     _check_sha256_no_check_if_latest
     _check_sourceforge_download_url_format
     _check_download(download) if download
@@ -27,7 +26,7 @@ class Cask::Audit
 
   def _check_required_stanzas
     odebug "Auditing required stanzas"
-    %i{version url homepage}.each do |sym|
+    %i{version sha256 url homepage}.each do |sym|
       add_error "a #{sym} stanza is required" unless cask.send(sym)
     end
     add_error 'a license value is required (:unknown is OK)' unless cask.license
@@ -37,12 +36,6 @@ class Cask::Audit
     add_error 'at least one activatable artifact stanza is required' unless installable_artifacts.size > 0
   end
 
-  def _check_checksums
-    odebug "Auditing checksums"
-    return if cask.sums == :no_check
-    add_error 'a sha256 stanza is required' unless cask.sums.is_a?(Array) && cask.sums.length > 0
-  end
-
   def _check_no_string_version_latest
     odebug "Verifying version :latest does not appear as a string ('latest')"
     if (cask.version == 'latest')
@@ -52,7 +45,7 @@ class Cask::Audit
 
   def _check_sha256_no_check_if_latest
     odebug "Verifying sha256 :no_check with version :latest"
-    if cask.version == :latest and cask.sums.is_a?(Array)
+    if cask.version == :latest and cask.sha256 != :no_check
       add_error "you should use sha256 :no_check when version is :latest"
     end
   end

lib/cask/cli.rb

@@ -117,7 +117,7 @@ class Cask::CLI
     Cask.init
     command = lookup_command(command_string)
     run_command(command, *rest)
-  rescue CaskError, ChecksumMismatchError => e
+  rescue CaskError, CaskSha256MismatchError => e
     onoe e
     $stderr.puts e.backtrace if Cask.debug
     exit 1

lib/cask/cli/internal_stanza.rb

@@ -6,7 +6,7 @@ class Cask::CLI::InternalStanza < Cask::CLI::InternalUseBase
   #
   # If no tokens are given, then data for all Casks is returned.
   #
-  # The pseudo-stanzas "artifacts" and "sums" are available.
+  # The pseudo-stanza "artifacts" is available.
   #
   # On failure, a blank line is returned on the standard output.
   #
@@ -70,7 +70,6 @@ class Cask::CLI::InternalStanza < Cask::CLI::InternalUseBase
 
   def self.print_stanzas(stanza, format=nil, table=nil, quiet=nil, *cask_tokens)
     count = 0
-    stanza = :sums      if stanza == :sha256
     stanza = :full_name if stanza == :name
     if ARTIFACTS.include?(stanza)
       artifact_name = stanza
@@ -118,9 +117,6 @@ class Cask::CLI::InternalStanza < Cask::CLI::InternalUseBase
       else
         if artifact_name or value.is_a?(Symbol)
           puts value.inspect
-        elsif stanza == :sums
-          # hack. why does "to_s" equal "inspect" for checksum objects?
-          puts value
         else
           puts value.to_s
         end

lib/cask/download.rb

@@ -27,25 +27,31 @@ class Cask::Download
                    HOMEBREW_CACHE_CASKS.join(downloaded_path.basename)
     rescue StandardError => e
     end
-    _check_sums(downloaded_path, cask.sums) unless cask.sums === :no_check
+    _compare_sha256(downloaded_path, cask)
     downloaded_path
   end
 
   private
-  def _check_sums(path, sums)
-    has_sum = false
-    sums.each do |sum|
-      unless sum.empty?
-        computed = Checksum.new(sum.hash_type, Digest.const_get(sum.hash_type.to_s.upcase).file(path).hexdigest)
-        if sum == computed
-          odebug "Checksums match"
-        else
-          ohai 'Note: running "brew update" may fix checksum errors'
-          raise ChecksumMismatchError.new(path, sum, computed)
-        end
-        has_sum = true
-      end
+  def _calc_sha256(path)
+    require 'digest/sha2'
+    Digest::SHA2.file(path).hexdigest
+  end
+
+  def _compare_sha256(path, cask)
+    begin
+      expected = cask.sha256
+    rescue RuntimeError => e
+    end
+    return if expected == :no_check
+    computed = _calc_sha256(path)
+    if expected.nil? or expected.empty?
+      raise CaskSha256MissingError.new("sha256 required: sha256 '#{computed}'")
+    end
+    if expected == computed
+      odebug "SHA256 checksums match"
+    else
+      ohai 'Note: running "brew update" may fix sha256 checksum errors'
+      raise CaskSha256MismatchError.new(path, expected, computed)
     end
-    raise ChecksumMissingError.new("Checksum required: sha256 '#{Digest::SHA256.file(path).hexdigest}'") unless has_sum
   end
 end

lib/cask/dsl.rb

@@ -1,4 +1,3 @@
-require 'checksum'
 require 'set'
 
 module Cask::DSL; end
@@ -44,7 +43,7 @@ module Cask::DSL
 
   def tags; self.class.tags; end
 
-  def sums; self.class.sums || []; end
+  def sha256; self.class.sha256; end
 
   def artifacts; self.class.artifacts; end
 
@@ -149,6 +148,21 @@ module Cask::DSL
       @version ||= arg
     end
 
+    SYMBOLIC_SHA256S = Set.new [
+      :no_check,
+    ]
+
+    def sha256(arg=nil)
+      if arg.nil?
+        @sha256
+      elsif @sha256
+        raise CaskInvalidError.new(self.token, "'sha256' stanza may only appear once")
+      elsif !arg.is_a?(String) and !SYMBOLIC_SHA256S.include?(arg)
+        raise CaskInvalidError.new(self.token, "invalid 'sha256' value: '#{arg.inspect}'")
+      end
+      @sha256 ||= arg
+    end
+
     def tags(*args)
       return @tags if args.empty?
       if @tags and !args.empty?
@@ -296,21 +310,6 @@ module Cask::DSL
       end
     end
 
-    attr_reader :sums
-
-    def hash_name(hash_type)
-      hash_type.to_s == 'sha2' ? 'sha256' : hash_type.to_s
-    end
-
-    def sha256(sha2=nil)
-      if sha2 == :no_check
-        @sums = sha2
-      else
-        @sums ||= []
-        @sums << Checksum.new(:sha2, sha2) unless sha2.nil?
-      end
-    end
-
     def method_missing(method, *args)
       Cask::Utils.method_missing_message(method, self.token)
       return nil

lib/cask/exceptions.rb

@@ -103,3 +103,25 @@ class CaskInvalidError < CaskError
     "Cask '#{token}' definition is invalid" + (submsg.length > 0 ? ": #{submsg}" : '')
   end
 end
+
+class CaskSha256MissingError < ArgumentError
+end
+
+class CaskSha256MismatchError < RuntimeError
+  attr_reader :path, :expected, :actual
+  def initialize(path, expected, actual)
+    @path = path
+    @expected = expected
+    @actual = actual
+  end
+
+  def to_s
+    <<-EOS.undent
+      sha256 mismatch
+      Expected: #{expected}
+      Actual: #{actual}
+      File: #{path}
+      To retry an incomplete download, remove the file above.
+      EOS
+  end
+end

lib/cask/utils.rb

@@ -1,3 +1,4 @@
+# coding: utf-8
 # see Homebrew Library/Homebrew/utils.rb
 
 require 'yaml'
@@ -101,7 +102,7 @@ module Cask::Utils
        :version,
        :license,
        :tags,
-       :sums,
+       :sha256,
        :artifacts,
        :caveats,
        :depends_on,

lib/homebrew-fork/Library/Homebrew/checksum.rb

@@ -1,19 +0,0 @@
-class Checksum
-  attr_reader :hash_type, :hexdigest
-  alias_method :to_s, :hexdigest
-
-  TYPES = [:sha1, :sha256]
-
-  def initialize(hash_type, hexdigest)
-    @hash_type = hash_type
-    @hexdigest = hexdigest
-  end
-
-  def empty?
-    hexdigest.empty?
-  end
-
-  def ==(other)
-    hash_type == other.hash_type && hexdigest == other.hexdigest
-  end
-end

lib/homebrew-fork/Library/Homebrew/exceptions.rb

@@ -8,24 +8,3 @@ end
 
 # raised in CurlDownloadStrategy.fetch
 class CurlDownloadStrategyError < RuntimeError; end
-
-# raised by Pathname#verify_checksum when "expected" is nil or empty
-class ChecksumMissingError < ArgumentError; end
-
-# raised by Pathname#verify_checksum when verification fails
-class ChecksumMismatchError < RuntimeError
-  attr_reader :expected, :hash_type
-
-  def initialize fn, expected, actual
-    @expected = expected
-    @hash_type = expected.hash_type.to_s.upcase
-
-    super <<-EOS.undent
-      #{@hash_type} mismatch
-      Expected: #{expected}
-      Actual: #{actual}
-      Archive: #{fn}
-      To retry an incomplete download, remove the file above.
-      EOS
-  end
-end

lib/homebrew-fork/Library/Homebrew/extend/pathname.rb

@@ -57,28 +57,6 @@ class Pathname
     %r[^#!\s*\S+] === open('r') { |f| f.read(1024) }
   end
 
-  def incremental_hash(klass)
-    digest = klass.new
-    if digest.respond_to?(:file)
-      digest.file(self)
-    else
-      buf = ""
-      open("rb") { |f| digest << buf while f.read(1024, buf) }
-    end
-    digest.hexdigest
-  end
-
-  def sha256
-    require 'digest/sha2'
-    incremental_hash(Digest::SHA2)
-  end
-
-  def verify_checksum expected
-    raise ChecksumMissingError if expected.nil? or expected.empty?
-    actual = Checksum.new(expected.hash_type, send(expected.hash_type).downcase)
-    raise ChecksumMismatchError.new(self, expected, actual) unless expected == actual
-  end
-
   # FIXME eliminate the places where we rely on this method
   alias_method :to_str, :to_s unless method_defined?(:to_str)
 

lib/homebrew-fork/Library/Homebrew/resource.rb

@@ -1,5 +1,4 @@
 require 'download_strategy'
-require 'checksum'
 require 'version'
 
 # Resource is the fundamental representation of an external resource. The
@@ -7,8 +6,8 @@ require 'version'
 # of this class.
 class Resource
 
-  attr_reader :checksum, :mirrors, :specs, :using
-  attr_writer :url, :checksum, :version
+  attr_reader :mirrors, :specs, :using
+  attr_writer :url, :version
   attr_accessor :download_strategy
 
   # Formula name must be set after the DSL, as we have no access to the
@@ -21,7 +20,6 @@ class Resource
     @version = nil
     @mirrors = []
     @specs = {}
-    @checksum = nil
     @using = nil
     instance_eval(&block) if block_given?
   end
@@ -87,21 +85,6 @@ class Resource
     cached_download
   end
 
-  def verify_download_integrity fn
-    if fn.respond_to?(:file?) && fn.file?
-      ohai "Verifying #{fn.basename} checksum" if ARGV.verbose?
-      fn.verify_checksum(checksum)
-    end
-  rescue ChecksumMissingError
-    opoo "Cannot verify integrity of #{fn.basename}"
-    puts "A checksum was not provided for this resource"
-    puts "For your reference the SHA1 is: #{fn.sha1}"
-  end
-
-  Checksum::TYPES.each do |type|
-    define_method(type) { |val| @checksum = Checksum.new(type, val) }
-  end
-
   def url val=nil, specs={}
     return @url if val.nil?
     @url = val

test/cask/dsl_test.rb

@@ -114,9 +114,7 @@ describe Cask::DSL do
         sha256 'imasha2'
       end
       instance = ChecksumCask.new
-      instance.sums.must_equal [
-                                Checksum.new(:sha2, 'imasha2')
-                               ]
+      instance.sha256.must_equal 'imasha2'
     end
   end
 

test/cask/installer_test.rb

@@ -162,7 +162,7 @@ describe Cask::Installer do
         shutup do
           Cask::Installer.new(bad_checksum).install
         end
-      }.must_raise(ChecksumMismatchError)
+      }.must_raise(CaskSha256MismatchError)
     end
 
     it "blows up on a missing checksum" do
@@ -171,7 +171,7 @@ describe Cask::Installer do
         shutup do
           Cask::Installer.new(missing_checksum).install
         end
-      }.must_raise(ChecksumMissingError)
+      }.must_raise(CaskSha256MissingError)
     end
 
     it "installs fine if sha256 :no_check is used" do