Merge pull request #3001 from reitermarkus/cask-conflicts-with

Implement `conflicts_with :cask`.

Library/Homebrew/cask/lib/hbc/dsl/conflicts_with.rb

@@ -10,25 +10,20 @@ module Hbc
         :java,
       ]
 
-      attr_accessor(*VALID_KEYS)
-      attr_accessor :pairs
+      attr_reader *VALID_KEYS
 
       def initialize(pairs = {})
         @pairs = pairs
+
+        VALID_KEYS.each do |key|
+          instance_variable_set("@#{key}", Set.new)
+        end
+
         pairs.each do |key, value|
           raise "invalid conflicts_with key: '#{key.inspect}'" unless VALID_KEYS.include?(key)
-          writer_method = "#{key}=".to_sym
-          send(writer_method, value)
+          instance_variable_set("@#{key}", instance_variable_get("@#{key}").merge([*value]))
         end
       end
-
-      def to_yaml
-        @pairs.to_yaml
-      end
-
-      def to_s
-        @pairs.inspect
-      end
     end
   end
 end

Library/Homebrew/cask/lib/hbc/exceptions.rb

@@ -17,6 +17,19 @@ module Hbc
     end
   end
 
+  class CaskConflictError < AbstractCaskErrorWithToken
+    attr_reader :conflicting_cask
+
+    def initialize(token, conflicting_cask)
+      super(token)
+      @conflicting_cask = conflicting_cask
+    end
+
+    def to_s
+      "Cask '#{token}' conflicts with '#{conflicting_cask}'."
+    end
+  end
+
   class CaskUnavailableError < AbstractCaskErrorWithToken
     def to_s
       "Cask '#{token}' is unavailable" << (reason.empty? ? "." : ": #{reason}")

Library/Homebrew/cask/lib/hbc/installer.rb

@@ -86,6 +86,8 @@ module Hbc
         raise CaskAlreadyInstalledError, @cask
       end
 
+      check_conflicts
+
       print_caveats
       fetch
       uninstall_existing_cask if @reinstall
@@ -98,6 +100,21 @@ module Hbc
       puts summary
     end
 
+    def check_conflicts
+      return unless @cask.conflicts_with
+
+      @cask.conflicts_with.cask.each do |conflicting_cask|
+        begin
+          conflicting_cask = CaskLoader.load(conflicting_cask)
+          if conflicting_cask.installed?
+            raise CaskConflictError.new(@cask, conflicting_cask)
+          end
+        rescue CaskUnavailableError
+          next # Ignore conflicting Casks that do not exist.
+        end
+      end
+    end
+
     def reinstall
       odebug "Hbc::Installer#reinstall"
       @reinstall = true

Library/Homebrew/test/cask/conflicts_with_spec.rb

@@ -0,0 +1,23 @@
+describe "conflicts_with", :cask do
+  describe "conflicts_with cask" do
+    let(:local_caffeine) {
+      Hbc::CaskLoader.load_from_file(TEST_FIXTURE_DIR/"cask/Casks/local-caffeine.rb")
+    }
+
+    let(:with_conflicts_with) {
+      Hbc::CaskLoader.load_from_file(TEST_FIXTURE_DIR/"cask/Casks/with-conflicts-with.rb")
+    }
+
+    it "installs the dependency of a Cask and the Cask itself", :focus do
+      Hbc::Installer.new(local_caffeine).install
+
+      expect(local_caffeine).to be_installed
+
+      expect {
+        Hbc::Installer.new(with_conflicts_with).install
+      }.to raise_error(Hbc::CaskConflictError, "Cask 'with-conflicts-with' conflicts with 'local-caffeine'.")
+
+      expect(with_conflicts_with).not_to be_installed
+    end
+  end
+end

Library/Homebrew/test/support/fixtures/cask/Casks/with-conflicts-with.rb

@@ -5,7 +5,7 @@ cask 'with-conflicts-with' do
   url "file://#{TEST_FIXTURE_DIR}/cask/caffeine.zip"
   homepage 'http://example.com/with-conflicts-with'
 
-  conflicts_with formula: 'unar'
+  conflicts_with cask: 'local-caffeine'
 
   app 'Caffeine.app'
 end