Check blacklisted Casks when auditing.

In some cases, certain Casks shouldn't be resubmitted for specific reasons: difficult to maintain, developers maintain their own version, ...

To make sure these cases are restricted - we can add them to a blacklist and have the blacklist checked as part of the `brew cask audit` steps.

Library/Homebrew/cask/audit.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require "cask/blacklist"
 require "cask/checkable"
 require "cask/download"
 require "digest"
@@ -30,6 +31,7 @@ module Cask
     end
 
     def run!
+      check_blacklist
       check_required_stanzas
       check_version
       check_sha256
@@ -320,6 +322,13 @@ module Cask
       add_error "appcast at URL '#{appcast_stanza}' offline or looping"
     end
 
+    def check_blacklist
+      return if cask.tap&.user != "Homebrew"
+      return unless reason = Blacklist.blacklisted_reason(cask.token)
+
+      add_error "#{cask.token} is blacklisted: #{reason}"
+    end
+
     def check_https_availability
       return unless download
 

Library/Homebrew/cask/blacklist.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Cask
+  module Blacklist
+    def self.blacklisted_reason(name)
+      case name
+      when /^adobe\-(after|illustrator|indesign|photoshop|premiere)/
+        "Adobe casks were removed because they are too difficult to maintain."
+      when /^audacity$/
+        "Audacity was removed because it is too difficult to download programmatically."
+      when /^pharo$/
+        "Pharo developers maintain their own tap."
+      end
+    end
+  end
+end

Library/Homebrew/test/cask/audit_spec.rb

@@ -399,6 +399,28 @@ describe Cask::Audit, :cask do
       end
     end
 
+    describe "blacklist checks" do
+      context "when the Cask isn't blacklisted" do
+        let(:cask_token) { "adobe-air" }
+
+        it { is_expected.to pass }
+      end
+
+      context "when the Cask is blacklisted" do
+        context "and it's in the official Homebrew tap" do
+          let(:cask_token) { "adobe-illustrator" }
+
+          it { is_expected.to fail_with(/#{cask_token} is blacklisted: \w+/) }
+        end
+
+        context "and it isn't in the official Homebrew tap" do
+          let(:cask_token) { "pharo" }
+
+          it { is_expected.to pass }
+        end
+      end
+    end
+
     describe "latest with auto_updates checks" do
       let(:warning_msg) { "Casks with `version :latest` should not use `auto_updates`" }
 
@@ -541,8 +563,8 @@ describe Cask::Audit, :cask do
     context "when an exception is raised" do
       let(:cask) { instance_double(Cask::Cask) }
 
-      it "does not fail" do
+      it "fails the audit" do
-        expect(cask).to receive(:version).and_raise(StandardError.new)
+        expect(cask).to receive(:tap).and_raise(StandardError.new)
         expect(subject).to fail_with(/exception while auditing/)
       end
     end

Library/Homebrew/test/cask/blacklist_spec.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+describe Cask::Blacklist, :cask do
+  describe "::blacklisted_reason" do
+    matcher :blacklist do |name|
+      match do |expected|
+        expected.blacklisted_reason(name)
+      end
+    end
+
+    it { is_expected.not_to blacklist("adobe-air") }
+    it { is_expected.to blacklist("adobe-after-effects") }
+    it { is_expected.to blacklist("adobe-illustrator") }
+    it { is_expected.to blacklist("adobe-indesign") }
+    it { is_expected.to blacklist("adobe-photoshop") }
+    it { is_expected.to blacklist("adobe-premiere") }
+    it { is_expected.to blacklist("audacity") }
+    it { is_expected.to blacklist("pharo") }
+    it { is_expected.not_to blacklist("non-blacklisted-cask") }
+  end
+end

Library/Homebrew/test/support/fixtures/cask/Casks/adobe-air.rb

@@ -0,0 +1,10 @@
+cask 'adobe-air' do
+  version '1.2.3'
+  sha256 '8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b'
+
+  url 'https://brew.sh/TestCask.dmg'
+  name 'Adobe Air'
+  homepage 'https://brew.sh/'
+
+  app 'TestCask.app'
+end

Library/Homebrew/test/support/fixtures/cask/Casks/adobe-illustrator.rb

@@ -0,0 +1,10 @@
+cask 'adobe-illustrator' do
+  version '1.2.3'
+  sha256 '8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b'
+
+  url 'https://brew.sh/TestCask.dmg'
+  name 'Adobe Illustrator'
+  homepage 'https://brew.sh/'
+
+  app 'TestCask.app'
+end

Library/Homebrew/test/support/fixtures/third-party/Casks/pharo.rb

@@ -0,0 +1,10 @@
+cask 'pharo' do
+  version '1.2.3'
+  sha256 '8c62a2b791cf5f0da6066a0a4b6e85f62949cd60975da062df44adf887f4370b'
+
+  url 'https://brew.sh/ThirdParty.dmg'
+  name 'Pharo'
+  homepage 'https://brew.sh/'
+
+  app 'ThirdParty.app'
+end