cask: add list --json

Library/Homebrew/cask/cmd/list.rb

@@ -3,58 +3,69 @@
 module Cask
   class Cmd
     class List < AbstractCommand
-      option "-1", :one, false
-      option "--versions", :versions, false
-      option "--full-name", :full_name, false
+      option "-1",             :one, false
+      option "--versions",     :versions, false
+      option "--full-name",    :full_name, false
+      option "--json",         :json, false
 
-      def run
-        args.any? ? list : list_installed
+      def self.usage
+        <<~EOS
+          `cask list`, `cask ls` [<options>] [<casks>]
+
+          -1          - Force output to be one entry per line.
+                        This is the default when output is not to a terminal.
+          --versions  - Show the version number for installed formulae, or only the specified
+                        casks if <casks> are provided.
+          --full-name - Print casks with fully-qualified names.
+          --json      - Print a JSON representation of <cask>. See the docs for examples of using the JSON
+                        output: <https://docs.brew.sh/Querying-Brew>
+
+          List all installed casks.
+
+          If <casks> are provided, limit information to just those casks.
+        EOS
       end
 
-      def list
+      def self.help
+        "lists installed Casks or the casks provided in the arguments"
+      end
+
+      def run
+        output = args.any? ? provided_list : Caskroom.casks
+
+        if json?
+          puts JSON.generate(output.map(&:to_h))
+        elsif one?
+          puts output.map(&:to_s)
+        elsif full_name?
+          puts output.map(&:full_name).sort(&tap_and_name_comparison)
+        elsif versions?
+          puts output.map(&self.class.method(:format_versioned))
+        elsif !output.empty? && args.any?
+          puts output.map(&self.class.method(:list_artifacts))
+        elsif !output.empty?
+          puts Formatter.columns(output.map(&:to_s))
+        end
+      end
+
+      def provided_list
         casks.each do |cask|
           raise CaskNotInstalledError, cask unless cask.installed?
-
-          if one?
-            puts cask.token
-          elsif versions?
-            puts self.class.format_versioned(cask)
-          else
-            cask = CaskLoader.load(cask.installed_caskfile)
-            self.class.list_artifacts(cask)
-          end
         end
+        casks
       end
 
       def self.list_artifacts(cask)
         cask.artifacts.group_by(&:class).each do |klass, artifacts|
           next unless klass.respond_to?(:english_description)
 
-          ohai klass.english_description, artifacts.map(&:summarize_installed)
-        end
-      end
-
-      def list_installed
-        installed_casks = Caskroom.casks
-
-        if one?
-          puts installed_casks.map(&:to_s)
-        elsif versions?
-          puts installed_casks.map(&self.class.method(:format_versioned))
-        elsif full_name?
-          puts installed_casks.map(&:full_name).sort(&tap_and_name_comparison)
-        elsif !installed_casks.empty?
-          puts Formatter.columns(installed_casks.map(&:to_s))
+          return "==> #{klass.english_description}", artifacts.map(&:summarize_installed)
         end
       end
 
       def self.format_versioned(cask)
         cask.to_s.concat(cask.versions.map(&:to_s).join(" ").prepend(" "))
       end
-
-      def self.help
-        "with no args, lists installed Casks; given installed Casks, lists staged files"
-      end
     end
   end
 end

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

@@ -20,6 +20,26 @@ describe Cask::Cmd::List, :cask do
     EOS
   end
 
+  it "lists oneline" do
+    casks = %w[
+      local-caffeine
+      third-party/tap/third-party-cask
+      local-transmission
+    ].map { |c| Cask::CaskLoader.load(c) }
+
+    casks.each do |c|
+      InstallHelper.install_with_caskfile(c)
+    end
+
+    expect {
+      described_class.run("-1")
+    }.to output(<<~EOS).to_stdout
+      local-caffeine
+      local-transmission
+      third-party-cask
+    EOS
+  end
+
   it "lists full names" do
     casks = %w[
       local-caffeine
@@ -66,6 +86,31 @@ describe Cask::Cmd::List, :cask do
     end
   end
 
+  describe "lists json" do
+    let(:casks) { ["local-caffeine", "local-transmission"] }
+    let(:expected_output) {
+      <<~EOS
+        [{"token":"local-caffeine","name":[],"homepage":"https://brew.sh/","url":"file:///usr/local/Homebrew/Library/Homebrew/test/support/fixtures/cask/caffeine.zip","appcast":null,"version":"1.2.3","sha256":"67cdb8a02803ef37fdbf7e0be205863172e41a561ca446cd84f0d7ab35a99d94","artifacts":[["Caffeine.app"]],"caveats":null,"depends_on":{},"conflicts_with":null,"container":null,"auto_updates":null},{"token":"local-transmission","name":["Transmission"],"homepage":"https://brew.sh/","url":"file:///usr/local/Homebrew/Library/Homebrew/test/support/fixtures/cask/transmission-2.61.dmg","appcast":null,"version":"2.61","sha256":"e44ffa103fbf83f55c8d0b1bea309a43b2880798dae8620b1ee8da5e1095ec68","artifacts":[["Transmission.app"]],"caveats":null,"depends_on":{},"conflicts_with":null,"container":null,"auto_updates":null}]
+      EOS
+    }
+
+    before do
+      casks.map(&Cask::CaskLoader.method(:load)).each(&InstallHelper.method(:install_with_caskfile))
+    end
+
+    it "of all installed Casks" do
+      expect {
+        described_class.run("--json")
+      }.to output(expected_output).to_stdout
+    end
+
+    it "of given Casks" do
+      expect {
+        described_class.run("--json", "local-caffeine", "local-transmission")
+      }.to output(expected_output).to_stdout
+    end
+  end
+
   describe "given a set of installed Casks" do
     let(:caffeine) { Cask::CaskLoader.load(cask_path("local-caffeine")) }
     let(:transmission) { Cask::CaskLoader.load(cask_path("local-transmission")) }