Merge pull request #2020 from pry/command-global-state

pry_instance: factor out command state to be global

10 files changed, 100 insertions, 17 deletions

diff --git a/lib/pry.rb b/lib/pry.rb
index 3b4bcfe1..fbbaa2ab 100644
--- a/lib/pry.rb
+++ b/lib/pry.rb
@@ -24,6 +24,7 @@ require 'pry/color_printer'
 require 'pry/exception_handler'
 require 'pry/system_command_handler'
 require 'pry/control_d_handler'
+require 'pry/command_state'
 
 Pry::Commands = Pry::CommandSet.new unless defined?(Pry::Commands)
 
diff --git a/lib/pry/command.rb b/lib/pry/command.rb
index 81cded01..fa6d2e51 100644
--- a/lib/pry/command.rb
+++ b/lib/pry/command.rb
@@ -196,6 +196,10 @@ class Pry
                   end
         end
       end
+
+      def state
+        Pry::CommandState.default.state_for(match)
+      end
     end
 
     # Properties of one execution of a command (passed by {Pry#run_command} as a hash of
@@ -305,7 +309,7 @@ class Pry
     #   state.my_state = "my state"  # this will not conflict with any
     #                                # `state.my_state` used in another command.
     def state
-      pry_instance.command_state[match] ||= Pry::Config.from_hash({})
+      self.class.state
     end
 
     # Revaluate the string (str) and perform interpolation.
diff --git a/lib/pry/command_state.rb b/lib/pry/command_state.rb
new file mode 100644
index 00000000..263d14d8
--- /dev/null
+++ b/lib/pry/command_state.rb
@@ -0,0 +1,29 @@
+require 'ostruct'
+
+class Pry
+  # CommandState is a data structure to hold per-command state.
+  #
+  # Pry commands can store arbitrary state here. This state persists between
+  # subsequent command invocations. All state saved here is unique to the
+  # command.
+  #
+  # @since ?.?.?
+  # @api private
+  class CommandState
+    def self.default
+      @default ||= new
+    end
+
+    def initialize
+      @command_state = {}
+    end
+
+    def state_for(command_name)
+      @command_state[command_name] ||= OpenStruct.new
+    end
+
+    def reset(command_name)
+      @command_state[command_name] = OpenStruct.new
+    end
+  end
+end
diff --git a/lib/pry/control_d_handler.rb b/lib/pry/control_d_handler.rb
index d02e2110..1021c767 100644
--- a/lib/pry/control_d_handler.rb
+++ b/lib/pry/control_d_handler.rb
@@ -16,8 +16,8 @@ class Pry
       else
         # Otherwise, saves current binding stack as old stack and pops last
         # binding out of binding stack (the old stack still has that binding).
-        pry_instance.command_state['cd'] ||= Pry::Config.from_hash({})
-        pry_instance.command_state['cd'].old_stack = pry_instance.binding_stack.dup
+        cd_state = Pry::CommandState.default.state_for('cd')
+        cd_state.old_stack = pry_instance.binding_stack.dup
         pry_instance.binding_stack.pop
       end
     end
diff --git a/lib/pry/pry_instance.rb b/lib/pry/pry_instance.rb
index 9269ded7..e1309ce9 100644
--- a/lib/pry/pry_instance.rb
+++ b/lib/pry/pry_instance.rb
@@ -34,7 +34,6 @@ class Pry
   attr_accessor :last_dir
 
   attr_reader :last_exception
-  attr_reader :command_state
   attr_reader :exit_value
 
   # @since v0.12.0
@@ -72,7 +71,6 @@ class Pry
   def initialize(options = {})
     @binding_stack = []
     @indent        = Pry::Indent.new
-    @command_state = {}
     @eval_string   = ""
     @backtrace     = options.delete(:backtrace) || caller
     target = options.delete(:target)
diff --git a/spec/command_spec.rb b/spec/command_spec.rb
index f56d92db..b01cff07 100644
--- a/spec/command_spec.rb
+++ b/spec/command_spec.rb
@@ -416,6 +416,12 @@ RSpec.describe Pry::Command do
     end
   end
 
+  describe ".state" do
+    it "returns a command state" do
+      expect(described_class.state).to be_an(OpenStruct)
+    end
+  end
+
   describe "#run" do
     let(:command_set) do
       set = Pry::CommandSet.new
@@ -475,12 +481,12 @@ RSpec.describe Pry::Command do
     subject { Class.new(described_class).new(pry_instance: Pry.new) }
 
     it "returns a state hash" do
-      expect(subject.state).to be_a(Pry::Config)
+      expect(subject.state).to be_an(OpenStruct)
     end
 
     it "remembers the state" do
-      subject.state[:foo] = :bar
-      expect(subject.state[:foo]).to eq(:bar)
+      subject.state.foo = :bar
+      expect(subject.state.foo).to eq(:bar)
     end
   end
 
diff --git a/spec/command_state_spec.rb b/spec/command_state_spec.rb
new file mode 100644
index 00000000..10097b2b
--- /dev/null
+++ b/spec/command_state_spec.rb
@@ -0,0 +1,47 @@
+RSpec.describe Pry::CommandState do
+  describe ".default" do
+    it "returns the default command state" do
+      expect(described_class.default).to be_a(described_class)
+    end
+
+    context "when called multiple times" do
+      it "returns the same command state" do
+        first_state = described_class.default
+        second_state = described_class.default
+        expect(first_state).to eql(second_state)
+      end
+    end
+  end
+
+  describe "#state_for" do
+    it "returns a state for the matching command" do
+      subject.state_for('command').foobar = 1
+      expect(subject.state_for('command').foobar).to eq(1)
+    end
+
+    it "returns new state for new command" do
+      expect(subject.state_for('command'))
+        .not_to equal(subject.state_for('other-command'))
+    end
+
+    it "memoizes state for the same command" do
+      expect(subject.state_for('command')).to equal(subject.state_for('command'))
+    end
+  end
+
+  describe "#reset" do
+    it "resets the command state for the given command" do
+      subject.state_for('command').foobar = 1
+      subject.reset('command')
+      expect(subject.state_for('command').foobar).to be_nil
+    end
+
+    it "doesn't reset command state for other commands" do
+      subject.state_for('command').foobar = 1
+      subject.state_for('other-command').foobar = 1
+      subject.reset('command')
+
+      expect(subject.state_for('other-command').foobar).to eq(1)
+    end
+  end
+end
diff --git a/spec/commands/cd_spec.rb b/spec/commands/cd_spec.rb
index d2120a6e..38830ace 100644
--- a/spec/commands/cd_spec.rb
+++ b/spec/commands/cd_spec.rb
@@ -16,20 +16,16 @@ describe 'cd' do
       end
 
       def command_state
-        pry.command_state["cd"]
+        pry.commands['cd'].state
       end
 
       def old_stack
-        pry.command_state['cd'].old_stack.dup
+        pry.commands['cd'].state.old_stack.dup
       end
     end
   end
 
-  describe 'state' do
-    it 'should not to be set up in fresh instance' do
-      expect(@t.command_state).to equal nil
-    end
-  end
+  after { Pry::CommandState.default.reset('cd') }
 
   describe 'old stack toggling with `cd -`' do
     describe 'in fresh pry instance' do
diff --git a/spec/commands/shell_command_spec.rb b/spec/commands/shell_command_spec.rb
index 4417f0ee..62526b3c 100644
--- a/spec/commands/shell_command_spec.rb
+++ b/spec/commands/shell_command_spec.rb
@@ -5,11 +5,13 @@ describe Pry::Command::ShellCommand do
 
       @t = pry_tester(@o) do
         def command_state
-          pry.command_state[Pry::Command::ShellCommand.match]
+          Pry::CommandState.default.state_for(Pry::Command::ShellCommand.match)
         end
       end
     end
 
+    after { Pry::CommandState.default.reset(Pry::Command::ShellCommand.match) }
+
     describe ".cd" do
       before do
         allow(Dir).to receive(:chdir)
diff --git a/spec/control_d_handler_spec.rb b/spec/control_d_handler_spec.rb
index 2c5a45ae..5e21ccbe 100644
--- a/spec/control_d_handler_spec.rb
+++ b/spec/control_d_handler_spec.rb
@@ -37,7 +37,7 @@ RSpec.describe Pry::ControlDHandler do
 
     it "saves a dup of the current binding stack in the 'cd' command" do
       described_class.default(eval_string, pry_instance)
-      cd_state = pry_instance.command_state['cd']
+      cd_state = pry_instance.commands['cd'].state
       expect(cd_state.old_stack).to eq([binding1, binding2])
     end