checksum: simplify, use only sha256

We use only one sha type right now.

Needed for https://github.com/Homebrew/brew/pull/10186

Library/Homebrew/cask/dsl.rb

@@ -214,7 +214,7 @@ module Cask
         when :no_check
           arg
         when String
-          Checksum.new(:sha256, arg)
+          Checksum.new(arg)
         else
           raise CaskInvalidError.new(cask, "invalid 'sha256' value: '#{arg.inspect}'")
         end

Library/Homebrew/checksum.rb

@@ -7,12 +7,9 @@
 class Checksum
   extend Forwardable
 
-  attr_reader :hash_type, :hexdigest
+  attr_reader :hexdigest
 
-  TYPES = [:sha256].freeze
-
-  def initialize(hash_type, hexdigest)
-    @hash_type = hash_type
+  def initialize(hexdigest)
     @hexdigest = hexdigest.downcase
   end
 
@@ -23,7 +20,7 @@ class Checksum
     when String
       to_s == other.downcase
     when Checksum
-      hash_type == other.hash_type && hexdigest == other.hexdigest
+      hexdigest == other.hexdigest
     else
       false
     end

Library/Homebrew/cleanup.rb

@@ -94,7 +94,7 @@ module Homebrew
 
           if resource_name == "patch"
             patch_hashes = formula.stable&.patches&.select(&:external?)&.map(&:resource)&.map(&:version)
-            return true unless patch_hashes&.include?(Checksum.new(:sha256, version.to_s))
+            return true unless patch_hashes&.include?(Checksum.new(version.to_s))
           elsif resource_name && resource_version = formula.stable&.resources&.dig(resource_name)&.version
             return true if resource_version != version
           elsif version.is_a?(PkgVersion)

Library/Homebrew/cmd/fetch.rb

@@ -132,28 +132,28 @@ module Homebrew
     fetch_fetchable r, args: args
   rescue ChecksumMismatchError => e
     retry if retry_fetch?(r, args: args)
-    opoo "Resource #{r.name} reports different #{e.hash_type}: #{e.expected}"
+    opoo "Resource #{r.name} reports different sha256: #{e.expected}"
   end
 
   def fetch_formula(f, args:)
     fetch_fetchable f, args: args
   rescue ChecksumMismatchError => e
     retry if retry_fetch?(f, args: args)
-    opoo "Formula reports different #{e.hash_type}: #{e.expected}"
+    opoo "Formula reports different sha256: #{e.expected}"
   end
 
   def fetch_cask(cask_download, args:)
     fetch_fetchable cask_download, args: args
   rescue ChecksumMismatchError => e
     retry if retry_fetch?(cask_download, args: args)
-    opoo "Cask reports different #{e.hash_type}: #{e.expected}"
+    opoo "Cask reports different sha256: #{e.expected}"
   end
 
   def fetch_patch(p, args:)
     fetch_fetchable p, args: args
   rescue ChecksumMismatchError => e
     Homebrew.failed = true
-    opoo "Patch reports different #{e.hash_type}: #{e.expected}"
+    opoo "Patch reports different sha256: #{e.expected}"
   end
 
   def retry_fetch?(f, args:)
@@ -183,7 +183,7 @@ module Homebrew
     return unless download.file?
 
     puts "Downloaded to: #{download}" unless already_fetched
-    puts Checksum::TYPES.map { |t| "#{t.to_s.upcase}: #{download.send(t)}" }
+    puts "SHA256: #{download.sha256}"
 
     f.verify_download_integrity(download)
   end

Library/Homebrew/dev-cmd/bump-formula-pr.rb

@@ -162,11 +162,8 @@ module Homebrew
 
     check_for_mirrors(formula, old_mirrors, new_mirrors, args: args) if new_url.present?
 
-    hash_type, old_hash = if (checksum = formula_spec.checksum)
-      [checksum.hash_type, checksum.hexdigest]
-    end
-
-    new_hash = args[hash_type] if hash_type.present?
+    old_hash = formula_spec.checksum&.hexdigest
+    new_hash = args.sha256
     new_tag = args.tag
     new_revision = args.revision
     old_url = formula_spec.url
@@ -180,7 +177,7 @@ module Homebrew
     elsif new_tag && new_revision
       check_closed_pull_requests(formula, tap_full_name, url: old_url, tag: new_tag, args: args) if new_version.blank?
       false
-    elsif hash_type.blank?
+    elsif old_hash.blank?
       if new_tag.blank? && new_version.blank? && new_revision.blank?
         raise UsageError, "#{formula}: no --tag= or --version= argument specified!"
       end

Library/Homebrew/exceptions.rb

@@ -626,14 +626,13 @@ class ChecksumMissingError < ArgumentError; end
 
 # Raised by {Pathname#verify_checksum} when verification fails.
 class ChecksumMismatchError < RuntimeError
-  attr_reader :expected, :hash_type
+  attr_reader :expected
 
   def initialize(path, expected, actual)
     @expected = expected
-    @hash_type = expected.hash_type.to_s.upcase
 
     super <<~EOS
-      #{@hash_type} mismatch
+      SHA256 mismatch
       Expected: #{Formatter.success(expected.to_s)}
         Actual: #{Formatter.error(actual.to_s)}
           File: #{path}

Library/Homebrew/extend/pathname.rb

@@ -303,7 +303,7 @@ class Pathname
   def verify_checksum(expected)
     raise ChecksumMissingError if expected.blank?
 
-    actual = Checksum.new(expected.hash_type, send(expected.hash_type).downcase)
+    actual = Checksum.new(sha256.downcase)
     raise ChecksumMismatchError.new(self, expected, actual) unless expected == actual
   end
 

Library/Homebrew/formula.rb

@@ -1823,8 +1823,8 @@ class Formula
           bottle_url = "#{bottle_spec.root_url}/#{Bottle::Filename.create(self, os, bottle_spec.rebuild).bintray}"
           checksum = bottle_spec.collector[os]
           bottle_info["files"][os] = {
-            "url"                   => bottle_url,
-            checksum.hash_type.to_s => checksum.hexdigest,
+            "url"    => bottle_url,
+            "sha256" => checksum.hexdigest,
           }
         end
         hsh["bottle"]["stable"] = bottle_info
@@ -2418,8 +2418,8 @@ class Formula
     # tell you the currently valid value.
     #
     # <pre>sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7"</pre>
-    Checksum::TYPES.each do |type|
-      define_method(type) { |val| stable.send(type, val) }
+    def sha256(val)
+      stable.sha256(val)
     end
 
     # @!attribute [w] bottle

Library/Homebrew/resource.rb

@@ -162,8 +162,8 @@ class Resource
     EOS
   end
 
-  Checksum::TYPES.each do |type|
-    define_method(type) { |val| @checksum = Checksum.new(type, val) }
+  def sha256(val)
+    @checksum = Checksum.new(val)
   end
 
   def url(val = nil, **specs)

Library/Homebrew/software_spec.rb

@@ -33,7 +33,7 @@ class SoftwareSpec
                  :cached_download, :clear_cache, :checksum, :mirrors, :specs, :using, :version, :mirror,
                  :downloader
 
-  def_delegators :@resource, *Checksum::TYPES
+  def_delegators :@resource, :sha256
 
   def initialize(flags: [])
     @resource = Resource.new
@@ -411,11 +411,9 @@ class BottleSpecification
 
   # Checksum methods in the DSL's bottle block optionally take
   # a Hash, which indicates the platform the checksum applies on.
-  Checksum::TYPES.each do |cksum|
-    define_method(cksum) do |val|
-      digest, tag = val.shift
-      collector[tag] = Checksum.new(cksum, digest)
-    end
+  def sha256(val)
+    digest, tag = val.shift
+    collector[tag] = Checksum.new(digest)
   end
 
   def checksum_for(tag)
@@ -429,13 +427,12 @@ class BottleSpecification
       # Sort non-MacOS tags below MacOS tags.
       "0.#{tag}"
     end
-    checksums = {}
+    sha256s = []
     tags.reverse_each do |tag|
       checksum = collector[tag]
-      checksums[checksum.hash_type] ||= []
-      checksums[checksum.hash_type] << { checksum => tag }
+      sha256s << { checksum => tag }
     end
-    checksums
+    { sha256: sha256s }
   end
 end
 

Library/Homebrew/test/cask/download_spec.rb

@@ -25,7 +25,7 @@ module Cask
       end
 
       context "when expected and computed checksums match" do
-        let(:expected_sha256) { Checksum.new(:sha256, cafebabe) }
+        let(:expected_sha256) { Checksum.new(cafebabe) }
 
         it "does not raise an error" do
           expect { verification }.not_to raise_error
@@ -41,7 +41,7 @@ module Cask
       end
 
       context "when the expected checksum is empty" do
-        let(:expected_sha256) { Checksum.new(:sha256, "") }
+        let(:expected_sha256) { Checksum.new("") }
 
         it "outputs an error" do
           expect { verification }.to output(/sha256 "#{computed_sha256}"/).to_stderr
@@ -49,7 +49,7 @@ module Cask
       end
 
       context "when expected and computed checksums do not match" do
-        let(:expected_sha256) { Checksum.new(:sha256, deadbeef) }
+        let(:expected_sha256) { Checksum.new(deadbeef) }
 
         it "raises an error" do
           expect { verification }.to raise_error ChecksumMismatchError

Library/Homebrew/test/checksum_spec.rb

@@ -5,21 +5,19 @@ require "checksum"
 
 describe Checksum do
   describe "#empty?" do
-    subject { described_class.new(:sha256, "") }
+    subject { described_class.new("") }
 
     it { is_expected.to be_empty }
   end
 
   describe "#==" do
-    subject { described_class.new(:sha256, TEST_SHA256) }
+    subject { described_class.new(TEST_SHA256) }
 
-    let(:other) { described_class.new(:sha256, TEST_SHA256) }
-    let(:other_reversed) { described_class.new(:sha256, TEST_SHA256.reverse) }
-    let(:other_sha1) { described_class.new(:sha1, TEST_SHA1) }
+    let(:other) { described_class.new(TEST_SHA256) }
+    let(:other_reversed) { described_class.new(TEST_SHA256.reverse) }
 
     it { is_expected.to eq(other) }
     it { is_expected.not_to eq(other_reversed) }
-    it { is_expected.not_to eq(other_sha1) }
     it { is_expected.not_to eq(nil) }
   end
 end

Library/Homebrew/test/resource_spec.rb

@@ -108,7 +108,7 @@ describe Resource do
 
     it "returns the checksum set with #sha256" do
       subject.sha256(TEST_SHA256)
-      expect(subject.checksum).to eq(Checksum.new(:sha256, TEST_SHA256))
+      expect(subject.checksum).to eq(Checksum.new(TEST_SHA256))
     end
   end
 

Library/Homebrew/test/software_spec_spec.rb

@@ -194,7 +194,7 @@ describe BottleSpecification do
     checksums.each_pair do |cat, digest|
       subject.sha256(digest => cat)
       checksum, = subject.checksum_for(cat)
-      expect(Checksum.new(:sha256, digest)).to eq(checksum)
+      expect(Checksum.new(digest)).to eq(checksum)
     end
   end