Refactor Tty.

2 files changed, 67 insertions, 3 deletions

diff --git a/Library/Homebrew/utils/github.rb b/Library/Homebrew/utils/github.rb
index b7ec538f9..e71039e12 100644
--- a/Library/Homebrew/utils/github.rb
+++ b/Library/Homebrew/utils/github.rb
@@ -14,7 +14,7 @@ module GitHub
       super <<-EOS.undent
         GitHub API Error: #{error}
         Try again in #{pretty_ratelimit_reset(reset)}, or create a personal access token:
-          #{Tty.em}https://github.com/settings/tokens/new?scopes=&description=Homebrew#{Tty.reset}
+          #{Tty.underline}https://github.com/settings/tokens/new?scopes=&description=Homebrew#{Tty.reset}
         and then set the token as: export HOMEBREW_GITHUB_API_TOKEN="your_new_token"
       EOS
     end
@@ -30,7 +30,7 @@ module GitHub
       if ENV["HOMEBREW_GITHUB_API_TOKEN"]
         message << <<-EOS.undent
           HOMEBREW_GITHUB_API_TOKEN may be invalid or expired; check:
-          #{Tty.em}https://github.com/settings/tokens#{Tty.reset}
+          #{Tty.underline}https://github.com/settings/tokens#{Tty.reset}
         EOS
       else
         message << <<-EOS.undent
@@ -38,7 +38,7 @@ module GitHub
           Clear them with:
             printf "protocol=https\\nhost=github.com\\n" | git credential-osxkeychain erase
           Or create a personal access token:
-            #{Tty.em}https://github.com/settings/tokens/new?scopes=&description=Homebrew#{Tty.reset}
+            #{Tty.underline}https://github.com/settings/tokens/new?scopes=&description=Homebrew#{Tty.reset}
           and then set the token as: export HOMEBREW_GITHUB_API_TOKEN="your_new_token"
         EOS
       end
diff --git a/Library/Homebrew/utils/tty.rb b/Library/Homebrew/utils/tty.rb
new file mode 100644
index 000000000..505165dc5
--- /dev/null
+++ b/Library/Homebrew/utils/tty.rb
@@ -0,0 +1,64 @@
+module Tty
+  module_function
+
+  def strip_ansi(string)
+    string.gsub(/\033\[\d+(;\d+)*m/, "")
+  end
+
+  def width
+    `/usr/bin/tput cols`.strip.to_i
+  end
+
+  def truncate(string)
+    (w = width).zero? ? string.to_s : string.to_s[0, w - 4]
+  end
+
+  COLOR_CODES = {
+    red: 31,
+    green: 32,
+    yellow: 33,
+    blue: 34,
+    magenta: 35,
+    cyan: 36,
+    default: 39,
+  }.freeze
+
+  STYLE_CODES = {
+    reset: 0,
+    bold: 1,
+    italic: 3,
+    underline: 4,
+    strikethrough: 9,
+    no_underline: 24,
+  }.freeze
+
+  CODES = COLOR_CODES.merge(STYLE_CODES).freeze
+
+  def append_to_escape_sequence(code)
+    @escape_sequence ||= []
+    @escape_sequence << code
+    self
+  end
+
+  def current_escape_sequence
+    return "" if @escape_sequence.nil?
+    "\033[#{@escape_sequence.join(";")}m"
+  end
+
+  def reset_escape_sequence!
+    @escape_sequence = nil
+  end
+
+  CODES.each do |name, code|
+    define_singleton_method(name) do
+      append_to_escape_sequence(code)
+    end
+  end
+
+  def to_s
+    return "" unless $stdout.tty?
+    current_escape_sequence
+  ensure
+    reset_escape_sequence!
+  end
+end