in case of multiple aliases referencing different prompts, provide

multiple choice from 'change-prompt' command.

2 files changed, 30 insertions, 2 deletions

diff --git a/lib/pry/commands/change_prompt.rb b/lib/pry/commands/change_prompt.rb
index c6e72a20..36382d09 100644
--- a/lib/pry/commands/change_prompt.rb
+++ b/lib/pry/commands/change_prompt.rb
@@ -11,13 +11,29 @@ class Pry::Command::ChangePrompt < Pry::ClassCommand
   BANNER
 
   def process(prompt)
-    if new_prompt = Pry::Prompt[prompt]
-      _pry_.prompt = new_prompt.proc_array
+    prompts = Pry::Prompt.all(prompt)
+    if prompts.size == 1
+      _pry_.prompt = prompts[0].proc_array
+    elsif prompts.size > 1
+      multiple_choice(prompts)
     else
       raise Pry::CommandError, "'#{prompt}' isn't a known prompt!"
     end
   end
 
   private
+  def multiple_choice(prompts)
+    _pry_.pager.page "Multiple aliases found, please choose:\n"
+    prompts.each.with_index(1) do |prompt, i|
+      _pry_.pager.page "#{i}) #{prompt.name} => #{prompt.alias_for}"
+    end
+    output.write "Choice: "
+    reply = _pry_.input.respond_to?(:gets) ? _pry_.input.gets : _pry_.input.readline
+    if reply =~ /^\d+$/ and reply.to_i <= prompts.size
+      _pry_.prompt = prompts[reply.to_i-1].proc_array
+    else
+      multiple_choice(prompts)
+    end
+  end
   Pry::Commands.add_command(self)
 end
diff --git a/lib/pry/prompt.rb b/lib/pry/prompt.rb
index dcd2405a..7c3672c4 100644
--- a/lib/pry/prompt.rb
+++ b/lib/pry/prompt.rb
@@ -85,6 +85,18 @@ module Pry::Prompt
   end
 
   #
+  # @param [String] name
+  #   The name of a prompt.
+  #
+  # @return [Array<PromptInfo>]
+  #   An array of {PromptInfo} objects.
+  #
+  def all(name)
+    name = name.to_s
+    all_prompts.select{|prompt| prompt.name == name}
+  end
+
+  #
   # Remove a prompt from Pry.
   # It will no longer be visible in the output of "list-prompts" or usable with the
   # "change-prompt" command.