Simplify Prompt APIprompt-simpler-api

Before this change when you set a prompt, you have to do the following:

```rb
Pry.config.prompt = Pry::Prompt[:simple][:value]
```

The `[:value]` part was leaking implementation details and it proved to be an
unnecessary step.

With this change we can do the following:

```rb
Pry.config.prompt = Pry::Prompt[:simple]
```

`[:value]` is omitted.

I have also refactored some tests and removed irrelevant ones.

The Array API for prompt is deprecated:
`Pry.config.prompt = [proc {}, proc {}]` emits a warning now.

10 files changed, 156 insertions, 156 deletions

diff --git a/lib/pry.rb b/lib/pry.rb
index afe1c12f..bd224ad6 100644
--- a/lib/pry.rb
+++ b/lib/pry.rb
@@ -110,6 +110,7 @@ require 'pry/commands'
 require 'pry/plugins'
 require 'pry/core_extensions'
 require 'pry/basic_object'
+require "pry/prompt"
 require 'pry/config/behavior'
 require 'pry/config/memoization'
 require 'pry/config/default'
@@ -125,7 +126,6 @@ require 'pry/editor'
 require 'pry/rubygem'
 require "pry/indent"
 require "pry/last_exception"
-require "pry/prompt"
 require "pry/inspector"
 require 'pry/object_path'
 require 'pry/output'
diff --git a/lib/pry/cli.rb b/lib/pry/cli.rb
index a694ee7a..6fc021bc 100644
--- a/lib/pry/cli.rb
+++ b/lib/pry/cli.rb
@@ -180,11 +180,11 @@ Pry::CLI.add_options do
   end
 
   on "simple-prompt", "Enable simple prompt mode" do
-    Pry.config.prompt = Pry::Prompt[:simple][:value]
+    Pry.config.prompt = Pry::Prompt[:simple]
   end
 
   on "noprompt", "No prompt mode" do
-    Pry.config.prompt = Pry::Prompt[:none][:value]
+    Pry.config.prompt = Pry::Prompt[:none]
   end
 
   on :r, :require=, "`require` a Ruby script at startup" do |file|
diff --git a/lib/pry/commands/change_prompt.rb b/lib/pry/commands/change_prompt.rb
index 85696734..37d81da2 100644
--- a/lib/pry/commands/change_prompt.rb
+++ b/lib/pry/commands/change_prompt.rb
@@ -25,15 +25,15 @@ class Pry::Command::ChangePrompt < Pry::ClassCommand
 
   def list_prompts
     prompts = Pry::Prompt.all.map do |name, prompt|
-      "#{bold(name)}#{red(' (selected)') if _pry_.prompt == prompt[:value]}\n" +
-        prompt[:description]
+      "#{bold(name)}#{red(' (selected)') if _pry_.prompt == prompt}\n" +
+        prompt.description
     end
     output.puts(prompts.join("\n" * 2))
   end
 
   def change_prompt(prompt)
-    if Pry::Prompt.all.key?(prompt)
-      _pry_.prompt = Pry::Prompt.all[prompt][:value]
+    if Pry::Prompt[prompt]
+      _pry_.prompt = Pry::Prompt[prompt]
     else
       raise Pry::CommandError, "'#{prompt}' isn't a known prompt. " \
                                "Run `change-prompt --list` to see the list of known prompts."
diff --git a/lib/pry/commands/shell_mode.rb b/lib/pry/commands/shell_mode.rb
index b6b42f84..8cb8fe52 100644
--- a/lib/pry/commands/shell_mode.rb
+++ b/lib/pry/commands/shell_mode.rb
@@ -13,7 +13,7 @@ class Pry
 
       if state.disabled
         state.prev_prompt = _pry_.prompt
-        _pry_.prompt = Pry::Prompt[:shell][:value]
+        _pry_.prompt = Pry::Prompt[:shell]
       else
         _pry_.prompt = state.prev_prompt
       end
diff --git a/lib/pry/config/behavior.rb b/lib/pry/config/behavior.rb
index 8bb68f05..27efb81a 100644
--- a/lib/pry/config/behavior.rb
+++ b/lib/pry/config/behavior.rb
@@ -1,8 +1,14 @@
 class Pry
   class Config < Pry::BasicObject
+    # rubocop:disable Metrics/ModuleLength
     module Behavior
       ASSIGNMENT = "=".freeze
-      NODUP = [TrueClass, FalseClass, NilClass, Symbol, Numeric, Module, Proc].freeze
+
+      NODUP = [
+        TrueClass, FalseClass, NilClass, Symbol, Numeric, Module, Proc,
+        Pry::Prompt
+      ].freeze
+
       INSPECT_REGEXP = /#{Regexp.escape "default=#<"}/
       ReservedKeyError = Class.new(RuntimeError)
 
@@ -251,5 +257,6 @@ class Pry
         @lookup.delete(key)
       end
     end
+    # rubocop:enable Metrics/ModuleLength
   end
 end
diff --git a/lib/pry/config/default.rb b/lib/pry/config/default.rb
index 928df4e8..f7a5cd6b 100644
--- a/lib/pry/config/default.rb
+++ b/lib/pry/config/default.rb
@@ -18,7 +18,7 @@ class Pry
           Pry::Prompt::DEFAULT_NAME
         },
         prompt: proc {
-          Pry::Prompt[:default][:value]
+          Pry::Prompt[:default]
         },
         prompt_safe_contexts: proc {
           Pry::Prompt::SAFE_CONTEXTS
diff --git a/lib/pry/prompt.rb b/lib/pry/prompt.rb
index 1e43841a..cbb91870 100644
--- a/lib/pry/prompt.rb
+++ b/lib/pry/prompt.rb
@@ -19,7 +19,7 @@ class Pry
   #   # In [4]:
   # @since v0.11.0
   # @api public
-  module Prompt
+  class Prompt
     # @return [String]
     DEFAULT_NAME = 'pry'.freeze
 
@@ -35,7 +35,7 @@ class Pry
       # Retrieves a prompt.
       #
       # @example
-      #   Prompt[:my_prompt][:value]
+      #   Prompt[:my_prompt]
       #
       # @param [Symbol] name The name of the prompt you want to access
       # @return [Hash{Symbol=>Object}]
@@ -78,12 +78,13 @@ class Pry
           raise ArgumentError, "the '#{name}' prompt was already added"
         end
 
-        @prompts[name] = {
-          description: description,
-          value: separators.map do |sep|
+        @prompts[name] = new(
+          name,
+          description,
+          separators.map do |sep|
             proc { |context, nesting, _pry_| yield(context, nesting, _pry_, sep) }
           end
-        }
+        )
 
         nil
       end
@@ -97,10 +98,35 @@ class Pry
       end
     end
 
-    add 'default',
-        "The default Pry prompt. Includes information about the current expression \n" \
-        "number, evaluation context, and nesting level, plus a reminder that you're \n" \
-        'using Pry.' do |context, nesting, _pry_, sep|
+    # @return [String]
+    attr_reader :name
+
+    # @return [String]
+    attr_reader :description
+
+    def initialize(name, description, prompt_procs)
+      @name = name
+      @description = description
+      @prompt_procs = prompt_procs
+    end
+
+    # @return [Proc] the proc which builds the wait prompt (`>`)
+    def wait_proc
+      @prompt_procs.first
+    end
+
+    # @return [Proc] the proc which builds the prompt when in the middle of an
+    #   expression such as open method, etc. (`*`)
+    def incomplete_proc
+      @prompt_procs.last
+    end
+
+    add(
+      :default,
+      "The default Pry prompt. Includes information about the current expression \n" \
+      "number, evaluation context, and nesting level, plus a reminder that you're \n" \
+      'using Pry.'
+    ) do |context, nesting, _pry_, sep|
       format(
         "[%<in_count>s] %<name>s(%<context>s)%<nesting>s%<separator>s ",
         in_count: _pry_.input_ring.count,
@@ -112,7 +138,7 @@ class Pry
     end
 
     add(
-      'simple',
+      :simple,
       "A simple `>>`.",
       ['>> ', ' | ']
     ) do |_, _, _, sep|
@@ -120,7 +146,7 @@ class Pry
     end
 
     add(
-      'nav',
+      :nav,
       "A prompt that displays the binding stack as a path and includes information \n" \
       "about #{Helpers::Text.bold('_in_')} and #{Helpers::Text.bold('_out_')}.",
       %w[> *]
@@ -137,7 +163,7 @@ class Pry
     end
 
     add(
-      'shell',
+      :shell,
       'A prompt that displays `$PWD` as you change it.',
       %w[$ *]
     ) do |context, _nesting, _pry_, sep|
@@ -151,7 +177,7 @@ class Pry
     end
 
     add(
-      'none',
+      :none,
       'Wave goodbye to the Pry prompt.',
       Array.new(2)
     ) { '' }
diff --git a/lib/pry/pry_instance.rb b/lib/pry/pry_instance.rb
index 517df038..cd698ac7 100644
--- a/lib/pry/pry_instance.rb
+++ b/lib/pry/pry_instance.rb
@@ -58,7 +58,7 @@ class Pry
   #   The object to use for commands.
   # @option options [Hash] :hooks
   #   The defined hook Procs.
-  # @option options [Array<Proc>] :prompt
+  # @option options [Pry::Prompt] :prompt
   #   The array of Procs to use for prompts.
   # @option options [Proc] :print
   #   The Proc to use for printing return values.
@@ -85,14 +85,18 @@ class Pry
     @input_ring << nil
     push_initial_binding(target)
     exec_hook(:when_started, target, options, self)
+    @prompt_warn = false
   end
 
   # This is the prompt at the top of the prompt stack.
-  # @return [Array<Proc>] the current prompt
+  # @return [Pry::Prompt] the current prompt
   def prompt
     prompt_stack.last
   end
 
+  # Sets the Pry prompt.
+  # @param [Pry::Prompt] new_prompt
+  # @return [void]
   def prompt=(new_prompt)
     if prompt_stack.empty?
       push_prompt new_prompt
@@ -548,6 +552,22 @@ class Pry
       })
 
     Pry.critical_section do
+      # If input buffer is empty, then use normal prompt. Otherwise use the wait
+      # prompt (indicating multi-line expression).
+      if prompt.is_a?(Pry::Prompt)
+        prompt_proc = eval_string.empty? ? prompt.wait_proc : prompt.incomplete_proc
+        return prompt_proc.call(c.object, c.nesting_level, c._pry_)
+      end
+
+      unless @prompt_warn
+        @prompt_warn = true
+        output.warn(
+          "warning: setting prompt with help of " \
+          "`Pry.config.prompt = [proc {}, proc {}]` is deprecated. " \
+          "Use Pry::Prompt API instead"
+        )
+      end
+
       # If input buffer is empty then use normal prompt
       if eval_string.empty?
         generate_prompt(Array(prompt).first, c)
@@ -575,27 +595,28 @@ class Pry
 
   # Pushes the current prompt onto a stack that it can be restored from later.
   # Use this if you wish to temporarily change the prompt.
-  # @param [Array<Proc>] new_prompt
-  # @return [Array<Proc>] new_prompt
+  #
   # @example
-  #    new_prompt = [ proc { '>' }, proc { '>>' } ]
-  #    push_prompt(new_prompt) # => new_prompt
+  #   push_prompt(Pry::Prompt[:my_prompt])
+  #
+  # @param [Pry::Prompt] new_prompt
+  # @return [Pry::Prompt] new_prompt
   def push_prompt(new_prompt)
     prompt_stack.push new_prompt
   end
 
-  # Pops the current prompt off of the prompt stack.
-  # If the prompt you are popping is the last prompt, it will not be popped.
-  # Use this to restore the previous prompt.
-  # @return [Array<Proc>] Prompt being popped.
+  # Pops the current prompt off of the prompt stack. If the prompt you are
+  # popping is the last prompt, it will not be popped. Use this to restore the
+  # previous prompt.
+  #
   # @example
-  #    prompt1 = [ proc { '>' }, proc { '>>' } ]
-  #    prompt2 = [ proc { '$' }, proc { '>' } ]
-  #    pry = Pry.new :prompt => prompt1
-  #    pry.push_prompt(prompt2)
+  #    pry = Pry.new(prompt: Pry::Prompt[:my_prompt1])
+  #    pry.push_prompt(Pry::Prompt[:my_prompt2])
   #    pry.pop_prompt # => prompt2
   #    pry.pop_prompt # => prompt1
   #    pry.pop_prompt # => prompt1
+  #
+  # @return [Pry::Prompt] the prompt being popped
   def pop_prompt
     prompt_stack.size > 1 ? prompt_stack.pop : prompt
   end
diff --git a/spec/prompt_spec.rb b/spec/prompt_spec.rb
index c339282f..4ecdc760 100644
--- a/spec/prompt_spec.rb
+++ b/spec/prompt_spec.rb
@@ -23,7 +23,7 @@ describe Pry::Prompt do
 
     it "adds a new prompt" do
       described_class.add(:my_prompt)
-      expect(described_class[:my_prompt]).to be_a(Hash)
+      expect(described_class[:my_prompt]).to be_a(described_class)
     end
 
     it "raises error when separators.size != 2" do
@@ -42,87 +42,21 @@ describe Pry::Prompt do
     end
   end
 
-  describe "one-parameter prompt proc" do
-    it 'should get full config object' do
-      config = nil
-      redirect_pry_io(InputTester.new("exit-all")) do
-        Pry.start(self, prompt: proc { |v| config = v })
-      end
-      expect(config.is_a?(Pry::Config)).to eq true
-    end
-
-    it 'should get full config object, when using a proc array' do
-      config1 = nil
-      redirect_pry_io(InputTester.new("exit-all")) do
-        Pry.start(self, prompt: [proc { |v| config1 = v }, proc { |v| _config2 = v }])
-      end
-      expect(config1.is_a?(Pry::Config)).to eq true
-    end
-
-    it 'should receive correct data in the config object' do
-      config = nil
-      redirect_pry_io(InputTester.new("def hello", "exit-all")) do
-        Pry.start(self, prompt: proc { |v| config = v })
-      end
-
-      expect(config.eval_string).to match(/def hello/)
-      expect(config.nesting_level).to eq 0
-      expect(config.expr_number).to eq 1
-      expect(config.cont).to eq true
-      expect(config._pry_.is_a?(Pry)).to eq true
-      expect(config.object).to eq self
-    end
-
-    specify "object is Hash when current binding is a Hash" do
-      config = nil
-      h = {}
-      redirect_pry_io(InputTester.new("exit-all")) do
-        Pry.start(h, prompt: proc { |v| config = v })
-      end
-      expect(config.object).to be(h)
-    end
-  end
-
-  describe "BACKWARDS COMPATIBILITY: 3 parameter prompt proc" do
-    it 'should get 3 parameters' do
-      o = n = p = nil
-      redirect_pry_io(InputTester.new("exit-all")) do
-        Pry.start(:test, prompt: proc { |obj, nesting, _pry_|
-                    o, n, p = obj, nesting, _pry_ })
-      end
-      expect(o).to eq :test
-      expect(n).to eq 0
-      expect(p.is_a?(Pry)).to eq true
-    end
+  describe "prompt invocation" do
+    let(:pry) { Pry.new }
 
-    it 'should get 3 parameters, when using proc array' do
-      o1 = n1 = p1 = nil
-      redirect_pry_io(InputTester.new("exit-all")) do
-        Pry.start(:test, prompt: [proc { |obj, nesting, _pry_|
-                                       o1, n1, p1 = obj, nesting, _pry_ },
-                                  proc { |obj, nesting, _pry_|
-                                    _o2, _n2, _p2 = obj, nesting, _pry_ }])
+    let(:enum) do
+      Enumerator.new do |y|
+        range = ('a'..'z').to_enum
+        loop { y << range.next }
       end
-      expect(o1).to eq :test
-      expect(n1).to eq 0
-      expect(p1.is_a?(Pry)).to eq true
     end
-  end
 
-  it "can compute prompt name dynamically" do
-    config = nil
-    redirect_pry_io(InputTester.new("def hello", "exit-all")) do
-      Pry.start(self, prompt: proc { |v| config = v })
+    it "computes prompt name dynamically" do
+      proc = described_class[:default].wait_proc
+      pry.config.prompt_name = Pry.lazy { enum.next }
+      expect(proc.call(Object.new, 1, pry, '>')).to eq('[1] a(#<Object>):1> ')
+      expect(proc.call(Object.new, 1, pry, '>')).to eq('[1] b(#<Object>):1> ')
     end
-
-    enum = Enumerator.new do |y|
-      count = 100
-      loop { y << count += 1 }
-    end
-    config._pry_.config.prompt_name = Pry.lazy { enum.next }
-
-    proc = described_class[:default][:value].first
-    expect(proc.call(Object.new, 1, config._pry_)).to eq('[1] 101(#<Object>):1> ')
-    expect(proc.call(Object.new, 1, config._pry_)).to eq('[1] 102(#<Object>):1> ')
   end
 end
diff --git a/spec/pry_defaults_spec.rb b/spec/pry_defaults_spec.rb
index a0d79424..dd31150e 100644
--- a/spec/pry_defaults_spec.rb
+++ b/spec/pry_defaults_spec.rb
@@ -132,6 +132,12 @@ describe "test Pry defaults" do
       Pry.config.output = StringIO.new
     end
 
+    after do
+      %w[test new_test test1 test2 test3].each do |k|
+        Pry::Prompt.instance_variable_get(:@prompts).delete(k)
+      end
+    end
+
     def get_prompts(pry)
       a = pry.select_prompt
       pry.eval "["
@@ -141,15 +147,16 @@ describe "test Pry defaults" do
     end
 
     it 'should set the prompt default, and the default should be overridable (single prompt)' do
-      Pry.prompt = proc { "test prompt> " }
-      new_prompt = proc { "A" }
+      Pry::Prompt.add(:test, 'description') { 'test prompt> ' }
+      Pry.prompt = Pry::Prompt[:test]
+      Pry::Prompt.add(:new_test, 'description') { 'A' }
 
       pry = Pry.new
       expect(pry.prompt).to eq Pry.prompt
-      expect(get_prompts(pry)).to eq ["test prompt> ", "test prompt> "]
+      expect(get_prompts(pry)).to eq ['test prompt> ', 'test prompt> ']
 
-      pry = Pry.new(prompt: new_prompt)
-      expect(pry.prompt).to eq new_prompt
+      pry = Pry.new(prompt: Pry::Prompt[:new_test])
+      expect(pry.prompt).to eq Pry::Prompt[:new_test]
       expect(get_prompts(pry)).to eq ["A", "A"]
 
       pry = Pry.new
@@ -158,15 +165,21 @@ describe "test Pry defaults" do
     end
 
     it 'should set the prompt default, and the default should be overridable (multi prompt)' do
-      Pry.prompt = [proc { "test prompt> " }, proc { "test prompt* " }]
-      new_prompt = [proc { "A" }, proc { "B" }]
+      Pry::Prompt.add(:test, 'description', %w[> *]) do |_, _, _, sep|
+        "test prompt#{sep} "
+      end
+      Pry.prompt = Pry::Prompt[:test]
+
+      Pry::Prompt.add(:new_test, 'description') do |_, _, _, sep|
+        sep == '>' ? 'A' : 'B'
+      end
 
       pry = Pry.new
       expect(pry.prompt).to eq Pry.prompt
       expect(get_prompts(pry)).to eq ["test prompt> ", "test prompt* "]
 
-      pry = Pry.new(prompt: new_prompt)
-      expect(pry.prompt).to eq new_prompt
+      pry = Pry.new(prompt: Pry::Prompt[:new_test])
+      expect(pry.prompt).to eq Pry::Prompt[:new_test]
       expect(get_prompts(pry)).to eq ["A", "B"]
 
       pry = Pry.new
@@ -176,26 +189,25 @@ describe "test Pry defaults" do
 
     describe 'storing and restoring the prompt' do
       before do
-        make = lambda do |name,i|
-          prompt = [ proc { "#{i}>" } , proc { "#{i + 1}>" } ]
-          (class << prompt; self; end).send(:define_method, :inspect) { "<Prompt-#{name}>" }
-          prompt
-        end
-        @a , @b , @c = make[:a,0] , make[:b,1] , make[:c,2]
-        @pry = Pry.new prompt: @a
+        Pry::Prompt.add(:test1, 'description1') { sep }
+        Pry::Prompt.add(:test2, 'description2') { sep }
+        Pry::Prompt.add(:test3, 'description3') { sep }
+        @pry = Pry.new(prompt: Pry::Prompt[:test1])
       end
+
       it 'should have a prompt stack' do
-        @pry.push_prompt @b
-        @pry.push_prompt @c
-        expect(@pry.prompt).to eq @c
+        @pry.push_prompt(Pry::Prompt[:test2])
+        @pry.push_prompt(Pry::Prompt[:test3])
+        expect(@pry.prompt).to eq(Pry::Prompt[:test3])
         @pry.pop_prompt
-        expect(@pry.prompt).to eq @b
+        expect(@pry.prompt).to match(Pry::Prompt[:test2])
         @pry.pop_prompt
-        expect(@pry.prompt).to eq @a
+        expect(@pry.prompt).to eq(Pry::Prompt[:test1])
       end
 
-      it 'should restore overridden prompts when returning from file-mode' do
-        pry = Pry.new(prompt: [ proc { 'P>' } ] * 2)
+      it 'should restore overridden prompts when returning from shell-mode' do
+        Pry::Prompt.add(:test, 'description') { 'P>' }
+        pry = Pry.new(prompt: Pry::Prompt[:test])
         expect(pry.select_prompt).to eq "P>"
         pry.process_command('shell-mode')
         expect(pry.select_prompt).to match(/\Apry .* \$ \z/)
@@ -204,32 +216,32 @@ describe "test Pry defaults" do
       end
 
       it '#pop_prompt should return the popped prompt' do
-        @pry.push_prompt @b
-        @pry.push_prompt @c
-        expect(@pry.pop_prompt).to eq @c
-        expect(@pry.pop_prompt).to eq @b
+        @pry.push_prompt(Pry::Prompt[:test2])
+        @pry.push_prompt(Pry::Prompt[:test3])
+        expect(@pry.pop_prompt).to eq(Pry::Prompt[:test3])
+        expect(@pry.pop_prompt).to eq(Pry::Prompt[:test2])
       end
 
       it 'should not pop the last prompt' do
-        @pry.push_prompt @b
-        expect(@pry.pop_prompt).to eq @b
-        expect(@pry.pop_prompt).to eq @a
-        expect(@pry.pop_prompt).to eq @a
-        expect(@pry.prompt).to eq @a
+        @pry.push_prompt(Pry::Prompt[:test2])
+        expect(@pry.pop_prompt).to eq(Pry::Prompt[:test2])
+        expect(@pry.pop_prompt).to eq(Pry::Prompt[:test1])
+        expect(@pry.pop_prompt).to eq(Pry::Prompt[:test1])
+        expect(@pry.prompt).to eq(Pry::Prompt[:test1])
       end
 
       describe '#prompt= should replace the current prompt with the new prompt' do
         it 'when only one prompt on the stack' do
-          @pry.prompt = @b
-          expect(@pry.prompt).to eq @b
-          expect(@pry.pop_prompt).to eq @b
-          expect(@pry.pop_prompt).to eq @b
+          @pry.prompt = Pry::Prompt[:test2]
+          expect(@pry.prompt).to eq(Pry::Prompt[:test2])
+          expect(@pry.pop_prompt).to eq(Pry::Prompt[:test2])
+          expect(@pry.pop_prompt).to eq(Pry::Prompt[:test2])
         end
         it 'when several prompts on the stack' do
-          @pry.push_prompt @b
-          @pry.prompt = @c
-          expect(@pry.pop_prompt).to eq @c
-          expect(@pry.pop_prompt).to eq @a
+          @pry.push_prompt(Pry::Prompt[:test2])
+          @pry.prompt = Pry::Prompt[:test3]
+          expect(@pry.pop_prompt).to eq(Pry::Prompt[:test3])
+          expect(@pry.pop_prompt).to eq(Pry::Prompt[:test1])
         end
       end
     end