From 01fdf4c2f031b6f7d334f589d515dab266da343a Mon Sep 17 00:00:00 2001
From: Eloy Duran <eloy.de.enige@gmail.com>
Date: Sun, 31 Oct 2010 22:51:32 +0000
Subject: [PATCH] Add a auto_indent option to IRB::Formatter

git-svn-id: http://svn.macosforge.org/repository/ruby/DietRB/trunk@4855 23306eb0-4c56-4727-a40e-e92c0eb68959
---
 lib/irb/formatter.rb   | 30 ++++++++++++-------
 spec/formatter_spec.rb | 67 +++++++++++++++++++++++++++---------------
 2 files changed, 62 insertions(+), 35 deletions(-)

diff --git a/lib/irb/formatter.rb b/lib/irb/formatter.rb
index 1277502..efc9ce6 100644
--- a/lib/irb/formatter.rb
+++ b/lib/irb/formatter.rb
@@ -14,31 +14,34 @@ class Formatter
     SIMPLE_PROMPT  = ">> "
     NO_PROMPT      = ""
     RESULT_PREFIX  = "=>"
+    INDENTATION    = "  "
     SYNTAX_ERROR   = "SyntaxError: compile error\n(irb):%d: %s"
     SOURCE_ROOT    = Regexp.new("^#{File.expand_path('../../../', __FILE__)}")
     
     attr_writer   :prompt
     attr_accessor :inspect
+    attr_accessor :auto_indent
     attr_reader   :filter_from_backtrace
     
     def initialize
-      @prompt  = :default
-      @inspect = true
+      @prompt      = :default
+      @inspect     = true
+      @auto_indent = false
       @filter_from_backtrace = [SOURCE_ROOT]
     end
 
     def indentation(level)
-      '  ' * level
+      INDENTATION * level
     end
     
-    def prompt(context, indent = false)
+    def prompt(context, ignore_auto_indent = false)
       prompt = case @prompt
       when :default then DEFAULT_PROMPT % [context.object.inspect, context.line, context.level]
       when :simple  then SIMPLE_PROMPT
       else
         NO_PROMPT
       end
-      indent ? (prompt + indentation(context.level)) : prompt
+      @auto_indent && !ignore_auto_indent ? (prompt + indentation(context.level)) : prompt
     end
     
     def inspect_object(object)
@@ -58,12 +61,17 @@ def minimal_inspect_object(object)
     end
 
     def reindent_last_line_in_source(source)
-      old_level = source.level
-      yield
-      line      = source.buffer[-1]
-      new_line  = indentation(source.level < old_level ? source.level : old_level)
-      new_line += line.lstrip
-      source.buffer[-1] = new_line unless new_line == line
+      unless @auto_indent
+        yield
+        nil
+      else
+        old_level = source.level
+        yield
+        line      = source.buffer[-1]
+        new_line  = indentation(source.level < old_level ? source.level : old_level)
+        new_line += line.lstrip
+        source.buffer[-1] = new_line unless new_line == line
+      end
     end
 
     def result(object)
diff --git a/spec/formatter_spec.rb b/spec/formatter_spec.rb
index 420c04d..1d84ae1 100644
--- a/spec/formatter_spec.rb
+++ b/spec/formatter_spec.rb
@@ -78,34 +78,53 @@ def object.__id__; 2158110700; end
       "SyntaxError: compile error\n(irb):2: syntax error, unexpected '}'"
   end
 
-  it "pads the prompt, with indentation whitespace based on the source level, if requested" do
-    @formatter.prompt(@context, true).should == "irb(main):001:0> "
+  it "always skips re-indenting the last line in a Source#buffer if `auto_indent' is turned off" do
+    @context.source << "class A"
+    @formatter.reindent_last_line_in_source(@context.source) { @context.source << "def foo" }.should == nil
+    @context.source.buffer.last.should == "def foo"
+  end
 
-    @context.process_line("class A")
-    @formatter.prompt(@context, true).should == "irb(main):002:1>   "
-    @formatter.prompt(@context).should       == "irb(main):002:1> "
+  describe "with auto-indentation" do
+    before do
+      @formatter.auto_indent = true
+    end
 
-    @context.process_line("def foo")
-    @formatter.prompt(@context, true).should == "irb(main):003:2>     "
-    @formatter.prompt(@context).should       == "irb(main):003:2> "
-  end
+    it "returns the whitespace to append to the prompt, based on the given level" do
+      @formatter.indentation(0).should == ""
+      @formatter.indentation(1).should == "  "
+      @formatter.indentation(2).should == "    "
+    end
 
-  it "reindents the last line in a Source#buffer after execution of the block, and returns the new line" do
-    source = @context.source
-    lines = [
-      ["\tclass A", "class A"],
-      ["def foo",   "  def foo"],
-      ["    end",   "  end"],
-      ["    end",   "end"]
-    ]
-    lines.each do |line, expected_new_line|
-      @formatter.reindent_last_line_in_source(source) { source << line }.should == expected_new_line
+    it "pads the prompt, based on the source level" do
+      @formatter.prompt(@context).should == "irb(main):001:0> "
+      @context.process_line("class A")
+      @formatter.prompt(@context).should == "irb(main):002:1>   "
+      @context.process_line("def foo")
+      @formatter.prompt(@context).should == "irb(main):003:2>     "
     end
-    source.to_s.should == lines.map(&:last).join("\n")
-  end
 
-  it "returns nil if the last line was not reindented" do
-    @context.source << "class A"
-    @formatter.reindent_last_line_in_source(@context.source) { @context.source << "  def foo" }.should == nil
+    it "does not pad the prompt if it's explicitely specified" do
+      @context.process_line("class A")
+      @formatter.prompt(@context, true).should == "irb(main):002:1> "
+    end
+
+    it "reindents the last line in a Source#buffer after execution of the block, and returns the new line" do
+      source = @context.source
+      lines = [
+        ["\tclass A", "class A"],
+        ["def foo",   "  def foo"],
+        ["    end",   "  end"],
+        ["    end",   "end"]
+      ]
+      lines.each do |line, expected_new_line|
+        @formatter.reindent_last_line_in_source(source) { source << line }.should == expected_new_line
+      end
+      source.to_s.should == lines.map(&:last).join("\n")
+    end
+
+    it "returns nil if the last line was not reindented" do
+      @context.source << "class A"
+      @formatter.reindent_last_line_in_source(@context.source) { @context.source << "  def foo" }.should == nil
+    end
   end
 end