Add JSON support to brew cask outdated

* brew outdated already has JSON support, now users and tools can get
similar results with brew cask outdated --json

Library/Homebrew/cask/cmd/outdated.rb

@@ -5,30 +5,21 @@ module Cask
     class Outdated < AbstractCommand
       option "--greedy", :greedy, false
       option "--quiet",  :quiet, false
+      option "--json",   :json, false
 
       def initialize(*)
         super
         self.verbose = ($stdout.tty? || verbose?) && !quiet?
+        @outdated_casks = casks(alternative: -> { Caskroom.casks }).select do |cask|
+          odebug "Checking update info of Cask #{cask}"
+          cask.outdated?(greedy?)
+        end
       end
 
       def run
-        casks(alternative: -> { Caskroom.casks }).each do |cask|
+        output = @outdated_casks.map { |cask| cask.outdated_info(greedy?, verbose?, json?) }
-          odebug "Checking update info of Cask #{cask}"
-          self.class.list_if_outdated(cask, greedy?, verbose?)
-        end
-      end
 
-      def self.list_if_outdated(cask, greedy, verbose)
+        puts json? ? JSON.generate(output) : output
-        return unless cask.outdated?(greedy)
-
-        if verbose
-          outdated_versions = cask.outdated_versions(greedy)
-          outdated_info   = "#{cask.token} (#{outdated_versions.join(", ")})"
-          current_version = cask.version.to_s
-          puts "#{outdated_info} != #{current_version}"
-        else
-          puts cask.token
-        end
       end
 
       def self.help

Library/Homebrew/test/cask/cmd/outdated_spec.rb

@@ -88,4 +88,104 @@ describe Cask::Cmd::Outdated, :cask do
       EOS
     end
   end
+
+  describe "--json" do
+    it "lists outdated Casks in JSON format" do
+      result = [
+        {
+          name: "local-caffeine",
+          installed_versions: "1.2.2",
+          current_version: "1.2.3"
+        },
+        {
+          name: "local-transmission",
+          installed_versions: "2.60",
+          current_version: "2.61"
+        }
+      ].to_json
+
+      expect {
+        described_class.run("--json")
+      }.to output(result + "\n").to_stdout
+    end
+  end
+
+  describe "--json overrides --quiet" do
+    it "ignores --quiet and lists outdated Casks in JSON format" do
+      result = [
+        {
+          name: "local-caffeine",
+          installed_versions: "1.2.2",
+          current_version: "1.2.3"
+        },
+        {
+          name: "local-transmission",
+          installed_versions: "2.60",
+          current_version: "2.61"
+        }
+      ].to_json
+
+      expect {
+        described_class.run("--json", "--quiet")
+      }.to output(result + "\n").to_stdout
+    end
+  end
+
+  describe "--json and --greedy" do
+    it 'includes the Casks with "auto_updates true" or "version latest" in JSON format' do
+      result = [
+        {
+          name: "auto-updates",
+          installed_versions: "2.57",
+          current_version: "2.61"
+        },
+        {
+          name: "local-caffeine",
+          installed_versions: "1.2.2",
+          current_version: "1.2.3"
+        },
+        {
+          name: "local-transmission",
+          installed_versions: "2.60",
+          current_version: "2.61"
+        },
+        {
+          name: "version-latest-string",
+          installed_versions: "latest",
+          current_version: "latest"
+        }
+      ].to_json
+
+      expect {
+        described_class.run("--json", "--greedy")
+      }.to output(result + "\n").to_stdout
+    end
+
+    it 'does not include the Casks with "auto_updates true" with no version change in JSON format' do
+      cask = Cask::CaskLoader.load(cask_path("auto-updates"))
+      InstallHelper.install_with_caskfile(cask)
+
+      result = [
+        {
+          name: "local-caffeine",
+          installed_versions: "1.2.2",
+          current_version: "1.2.3"
+        },
+        {
+          name: "local-transmission",
+          installed_versions: "2.60",
+          current_version: "2.61"
+        },
+        {
+          name: "version-latest-string",
+          installed_versions: "latest",
+          current_version: "latest"
+        }
+      ].to_json
+
+      expect {
+        described_class.run("--json", "--greedy")
+      }.to output(result + "\n").to_stdout
+    end
+  end
 end