hide prompt aliases that the terminal cannot display

5 files changed, 31 insertions, 8 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0e099d8..b1f2fae9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,9 @@
 ### HEAD
 
-* Add `Pry::Helpers::Text#displayable_character?`, and `Pry::Helpers::Text#snowman_ready?`.
+* Add `Pry::Helpers::Text#{displayable_character?,displayable_string?,snowman_ready?}`.
 * `Pry::Helpers::Text#default` is deprecated in favor of `Pry::Helpers::Colors#strip_color`.
 * Coloring functions such as `black()` etc respect `_pry_.color` automatically, see [#1637](https://github.com/pry/pry/pull/1637).
-* Add `Pry#helpers`, see [#1635](https://github.com/pry/pry/pull/1635)
+* Add `Pry#helpers`, see [#1635](https://github.com/pry/pry/pull/1635). Aliased as `Pry#h`.
 * Add `Pry::Helpers::Colors`, and a new `#paint` function.
 * Add clear-screen command ([#1630](https://github.com/pry/pry/pull/1630))
 * Fix [#1636](https://github.com/pry/pry/issues/1636)
diff --git a/lib/pry/commands/list_prompts.rb b/lib/pry/commands/list_prompts.rb
index 317dc7aa..6c426fdf 100644
--- a/lib/pry/commands/list_prompts.rb
+++ b/lib/pry/commands/list_prompts.rb
@@ -13,7 +13,7 @@ class Pry::Command::ListPrompts < Pry::ClassCommand
     output.puts heading("Available prompts") + "\n\n"
     all_prompts.each do |prompt|
       next if prompt.alias?
-      aliases = Pry::Prompt.aliases_for(prompt.name)
+      aliases = Pry::Prompt.aliases_for(prompt.name, _pry_)
       output.write "Name: #{text.bold(prompt.name)}"
       output.puts selected_prompt?([prompt].concat(aliases)) ? text.green(" [active]") : ""
       output.puts "Aliases: #{aliases.map {|s| text.bold(s.name) }.join(',')}" if aliases.any?
diff --git a/lib/pry/helpers/text.rb b/lib/pry/helpers/text.rb
index d4b9fc13..0ad53aa9 100644
--- a/lib/pry/helpers/text.rb
+++ b/lib/pry/helpers/text.rb
@@ -69,12 +69,22 @@ class Pry
       #   to deal with unicode characters (like MS Windows+cmd.exe).
       #
       def displayable_character?(char)
+        displayable_string? char.to_s[0]
+      end
+
+      #
+      # Same as {#displayable_character?} but operates on entire String instead of single
+      # character.
+      #
+      # @see #displayable_character?
+      #
+      def displayable_string?(str)
         require 'open3' if not defined?(Open3)
-        Open3.popen3 DISPLAY_CMD % {ruby: RbConfig.ruby, char: char.to_s[0]} do |_, stdout, stderr|
-          SNOWMAN == stdout.gets.chomp
+        Open3.popen3 DISPLAY_CMD % {ruby: RbConfig.ruby, str: str} do |_, stdout, _|
+          str == stdout.gets.chomp
         end
       end
-      DISPLAY_CMD = %q("%{ruby}" -e 'print "%{char}"').freeze
+      DISPLAY_CMD = %q("%{ruby}" -e 'print "%{str}"').freeze
       SNOWMAN = "☃".freeze
       private_constant :DISPLAY_CMD, :SNOWMAN
 
diff --git a/lib/pry/prompt.rb b/lib/pry/prompt.rb
index ea71b346..632aaf3c 100644
--- a/lib/pry/prompt.rb
+++ b/lib/pry/prompt.rb
@@ -37,14 +37,26 @@ module Pry::Prompt
   end
 
   #
+  # @note
+  #   When '_pry_' is in scope or explicitly passed as a second argument, aliases that cannot
+  #   be displayed in a terminal are not returned by this method. See
+  #   {Pry::Helpers::Text#displayable_string?}.
+  #
   # @param [String] prompt
   #   The name of a prompt.
   #
+  # @param [Pry] pry
+  #   An instance of `Pry`.
+  #
   # @return [Array<PromptInfo>]
   #   Returns an array of aliases for _prompt_, as {PromptInfo} objects.
   #
-  def aliases_for(prompt)
-    all_prompts.select{|prompt_info| prompt_info.alias_for == prompt.to_s}
+  def aliases_for(prompt_name, pry=defined?(_pry_) && _pry_)
+    prompt_name = prompt_name.to_s
+    all_prompts.select do |prompt_info|
+      prompt_info.alias_for == prompt_name and
+      (pry ? pry.h.displayable_string?(prompt_info.name) : true)
+    end
   end
 
   #
diff --git a/lib/pry/pry_instance.rb b/lib/pry/pry_instance.rb
index 24d88e15..b48bd9ed 100644
--- a/lib/pry/pry_instance.rb
+++ b/lib/pry/pry_instance.rb
@@ -105,6 +105,7 @@ class Pry
       end
     }.call
   end
+  alias_method :h, :helpers
 
   # The current prompt.
   # This is the prompt at the top of the prompt stack.