Output plain list when running brew cask search without a TTY.

Library/Homebrew/cask/lib/hbc/cli/search.rb

@@ -46,6 +46,11 @@ def self.search(*arguments)
       end
 
       def self.render_results(exact_match, partial_matches, remote_matches, search_term)
+        unless $stdout.tty?
+          puts [*exact_match, *partial_matches, *remote_matches]
+          return
+        end
+
         if !exact_match && partial_matches.empty?
           puts "No Cask found for \"#{search_term}\"."
           return

Library/Homebrew/test/cask/cli/search_spec.rb

@@ -1,60 +1,73 @@
 describe Hbc::CLI::Search, :cask do
+  before(:each) do
+    allow(Tty).to receive(:width).and_return(0)
+  end
+
   it "lists the available Casks that match the search term" do
     expect {
       Hbc::CLI::Search.run("local")
-    }.to output(<<-EOS.undent).to_stdout
+    }.to output(<<-EOS.undent).to_stdout.as_tty
       ==> Partial Matches
       local-caffeine
       local-transmission
     EOS
   end
 
+  it "outputs a plain list when stdout is not a TTY" do
+    expect {
+      Hbc::CLI::Search.run("local")
+    }.to output(<<-EOS.undent).to_stdout
+      local-caffeine
+      local-transmission
+    EOS
+  end
+
   it "shows that there are no Casks matching a search term that did not result in anything" do
     expect {
       Hbc::CLI::Search.run("foo-bar-baz")
-    }.to output("No Cask found for \"foo-bar-baz\".\n").to_stdout
+    }.to output("No Cask found for \"foo-bar-baz\".\n").to_stdout.as_tty
   end
 
   it "lists all available Casks with no search term" do
     expect {
       Hbc::CLI::Search.run
-    }.to output(/local-caffeine/).to_stdout
+    }.to output(/local-caffeine/).to_stdout.as_tty
   end
 
   it "ignores hyphens in search terms" do
     expect {
       Hbc::CLI::Search.run("lo-cal-caffeine")
-    }.to output(/local-caffeine/).to_stdout
+    }.to output(/local-caffeine/).to_stdout.as_tty
   end
 
   it "ignores hyphens in Cask tokens" do
     expect {
       Hbc::CLI::Search.run("localcaffeine")
-    }.to output(/local-caffeine/).to_stdout
+    }.to output(/local-caffeine/).to_stdout.as_tty
   end
 
   it "accepts multiple arguments" do
     expect {
       Hbc::CLI::Search.run("local caffeine")
-    }.to output(/local-caffeine/).to_stdout
+    }.to output(/local-caffeine/).to_stdout.as_tty
   end
 
   it "accepts a regexp argument" do
     expect {
       Hbc::CLI::Search.run("/^local-c[a-z]ffeine$/")
-    }.to output("==> Regexp Matches\nlocal-caffeine\n").to_stdout
+    }.to output("==> Regexp Matches\nlocal-caffeine\n").to_stdout.as_tty
   end
 
   it "Returns both exact and partial matches" do
     expect {
       Hbc::CLI::Search.run("test-opera")
-    }.to output(/^==> Exact Match\ntest-opera\n==> Partial Matches\ntest-opera-mail/).to_stdout
+    }.to output(/^==> Exact Match\ntest-opera\n==> Partial Matches\ntest-opera-mail/).to_stdout.as_tty
   end
 
   it "does not search the Tap name" do
     expect {
       Hbc::CLI::Search.run("caskroom")
-    }.to output(/^No Cask found for "caskroom"\.\n/).to_stdout
+    }.to output(/^No Cask found for "caskroom"\.\n/).to_stdout.as_tty
   end
 
   it "doesn't highlight packages that aren't installed" do

Library/Homebrew/test/spec_helper.rb

@@ -23,6 +23,7 @@
 require "test/support/helper/fixtures"
 require "test/support/helper/formula"
 require "test/support/helper/mktmpdir"
+require "test/support/helper/output_as_tty"
 require "test/support/helper/rubocop"
 
 require "test/support/helper/spec/shared_context/homebrew_cask" if OS.mac?
@@ -45,6 +46,7 @@
   config.include(Test::Helper::Fixtures)
   config.include(Test::Helper::Formula)
   config.include(Test::Helper::MkTmpDir)
+  config.include(Test::Helper::OutputAsTTY)
   config.include(Test::Helper::RuboCop)
 
   config.before(:each, :needs_compat) do

Library/Homebrew/test/support/helper/output_as_tty.rb

@@ -0,0 +1,84 @@
+require "delegate"
+
+module Test
+  module Helper
+    module OutputAsTTY
+      # This is a custom wrapper for the `output` matcher,
+      # used for testing output to a TTY:
+      #
+      #   expect {
+      #     print "test" if $stdout.tty?
+      #   }.to output("test").to_stdout.as_tty
+      #
+      #   expect {
+      #     # command
+      #   }.to output(...).to_stderr.as_tty.with_color
+      #
+      class Output < SimpleDelegator
+        def matches?(block)
+          return super(block) unless @tty
+
+          colored_tty_block = lambda do
+            instance_eval("$#{@output}").extend(Module.new do
+              def tty?
+                true
+              end
+
+              alias_method :isatty, :tty?
+            end)
+            block.call
+          end
+
+          return super(colored_tty_block) if @colors
+
+          uncolored_tty_block = lambda do
+            instance_eval <<-EOS
+              begin
+                captured_stream = StringIO.new
+
+                original_stream = $#{@output}
+                $#{@output} = captured_stream
+
+                colored_tty_block.call
+              ensure
+                $#{@output} = original_stream
+                $#{@output}.print Tty.strip_ansi(captured_stream.string)
+              end
+            EOS
+          end
+
+          super(uncolored_tty_block)
+        end
+
+        def to_stdout
+          @output = :stdout
+          super
+          self
+        end
+
+        def to_stderr
+          @output = :stderr
+          super
+          self
+        end
+
+        def as_tty
+          @tty = true
+          return self if [:stdout, :stderr].include?(@output)
+          raise "`as_tty` can only be chained to `stdout` or `stderr`."
+        end
+
+        def with_color
+          @colors = true
+          return self if @tty
+          raise "`with_color` can only be chained to `as_tty`."
+        end
+      end
+
+      def output(*args)
+        core_matcher = super(*args)
+        Output.new(core_matcher)
+      end
+    end
+  end
+end