handle back-searching for blocks from multiline methods

lib/method_source.rb

@@ -20,15 +20,19 @@ class SourceNotFoundError < StandardError; end
   # @param [Array] source_location The array returned by Method#source_location
   # @param [String]  method_name
   # @return [String] The method body
-  def self.source_helper(source_location, name=nil)
+  def self.source_helper(source_location, name=nil, options={})
     raise SourceNotFoundError, "Could not locate source for #{name}!" unless source_location
     file, line = *source_location
 
-    expression_at(lines_for(file), line)
+    expression_at(lines_for(file), line, options)
   rescue SyntaxError => e
     raise SourceNotFoundError, "Could not parse source for #{name}: #{e.message}"
   end
 
+  def self.expression_options
+    {}
+  end
+
   # Helper method responsible for opening source file and buffering up
   # the comments for a specified method. Defined here to avoid polluting
   # `Method` class.
@@ -158,6 +162,12 @@ def class_comment
     end
     alias module_comment class_comment
   end
+
+  module ProcExtensions
+    def source
+      MethodSource.source_helper(source_location, defined?(name) ? name : inspect, block: true)
+    end
+  end
 end
 
 class Method
@@ -173,5 +183,6 @@ class UnboundMethod
 class Proc
   include MethodSource::SourceLocation::ProcExtensions
   include MethodSource::MethodExtensions
+  include MethodSource::ProcExtensions
 end
 

lib/method_source/code_helpers.rb

@@ -25,18 +25,28 @@ def expression_at(file, line_number, options={})
 
       lines = file.is_a?(Array) ? file : file.each_line.to_a
 
-      relevant_lines = lines[(line_number - 1)..-1] || []
-
-      extract_first_expression(relevant_lines, options[:consume])
-    rescue SyntaxError => e
-      raise if options[:strict]
-
       begin
-        extract_first_expression(relevant_lines) do |code|
-          code.gsub(/\#\{.*?\}/, "temp")
+        relevant_lines = lines[(line_number - 1)..-1] || []
+
+        extract_first_expression(relevant_lines, options[:consume])
+      rescue SyntaxError => e
+        raise if options[:strict]
+
+        # blocks may be part of a multiline method call,
+        # and aren't valid if you cut off previous lines
+        if options[:block] && line_number > 1
+          # search backwards until it's valid
+          line_number -= 1
+          retry          
+        end
+
+        begin
+          extract_first_expression(relevant_lines) do |code|
+            code.gsub(/\#\{.*?\}/, "temp")
+          end
+        rescue SyntaxError
+          raise e
         end
-      rescue SyntaxError
-        raise e
       end
     end
 

spec/method_source_spec.rb

@@ -38,6 +38,10 @@
     @hello_instance_evaled_source_2 = "  def \#{name}_two()\n    if 40 + 4\n      45\n    end\n  end\n"
     @hello_class_evaled_source = "  def hello_\#{name}(*args)\n    send_mesg(:\#{name}, *args)\n  end\n"
     @hi_module_evaled_source = "  def hi_\#{name}\n    @var = \#{name}\n  end\n"
+    @multiline_method_block_source = <<~RUBY
+      MultilineMethodBlock = save_block(
+        ) {}
+    RUBY
   end
 
   it 'should define methods on Method and UnboundMethod and Proc' do
@@ -123,6 +127,10 @@
     it 'should return comment for class instance' do
       expect(C.new.method(:hello).class_comment).to eq(@class_comment)
     end
+
+    it 'should return source for a block from a multiline method' do
+      expect(MultilineMethodBlock.source).to eq(@multiline_method_block_source)
+    end
   end
   # end
   describe "Comment tests" do

spec/spec_helper.rb

@@ -105,3 +105,10 @@ def #{name}_two()
 
 M.class_eval "def #{name}_three; @tempfile.#{name}; end"
 
+# multiline method call
+def save_block(&block)
+  block
+end
+
+MultilineMethodBlock = save_block(
+  ) {}