Refactor eval_path and SourceFinder::Source (#870)

* Assign `@eval_path` through `irb_path=` method

This simplifies the original caching logic for the `eval_path` method
and makes it easier to understand.

* Refactor SourceFinder::Source

lib/irb/context.rb

@@ -77,7 +77,7 @@ def initialize(irb, workspace = nil, input_method = nil)
       else
         @irb_name = IRB.conf[:IRB_NAME]+"#"+IRB.JobManager.n_jobs.to_s
       end
-      @irb_path = "(" + @irb_name + ")"
+      self.irb_path = "(" + @irb_name + ")"
 
       case input_method
       when nil
@@ -121,11 +121,11 @@ def initialize(irb, workspace = nil, input_method = nil)
       when '-'
         @io = FileInputMethod.new($stdin)
         @irb_name = '-'
-        @irb_path = '-'
+        self.irb_path = '-'
       when String
         @io = FileInputMethod.new(input_method)
         @irb_name = File.basename(input_method)
-        @irb_path = input_method
+        self.irb_path = input_method
       else
         @io = input_method
       end
@@ -246,9 +246,27 @@ def main
     # Can be either name from <code>IRB.conf[:IRB_NAME]</code>, or the number of
     # the current job set by JobManager, such as <code>irb#2</code>
     attr_accessor :irb_name
-    # Can be either the #irb_name surrounded by parenthesis, or the
-    # +input_method+ passed to Context.new
-    attr_accessor :irb_path
+
+    # Can be one of the following:
+    # - the #irb_name surrounded by parenthesis
+    # - the +input_method+ passed to Context.new
+    # - the file path of the current IRB context in a binding.irb session
+    attr_reader :irb_path
+
+    # Sets @irb_path to the given +path+ as well as @eval_path
+    # @eval_path is used for evaluating code in the context of IRB session
+    # It's the same as irb_path, but with the IRB name postfix
+    # This makes sure users can distinguish the methods defined in the IRB session
+    # from the methods defined in the current file's context, especially with binding.irb
+    def irb_path=(path)
+      @irb_path = path
+
+      if File.exist?(path)
+        @eval_path = "#{path}(#{IRB.conf[:IRB_NAME]})"
+      else
+        @eval_path = path
+      end
+    end
 
     # Whether multiline editor mode is enabled or not.
     #
@@ -557,7 +575,7 @@ def evaluate(line, line_no) # :nodoc:
 
       if IRB.conf[:MEASURE] && !IRB.conf[:MEASURE_CALLBACKS].empty?
         last_proc = proc do
-          result = @workspace.evaluate(line, eval_path, line_no)
+          result = @workspace.evaluate(line, @eval_path, line_no)
         end
         IRB.conf[:MEASURE_CALLBACKS].inject(last_proc) do |chain, item|
           _name, callback, arg = item
@@ -568,20 +586,12 @@ def evaluate(line, line_no) # :nodoc:
           end
         end.call
       else
-        result = @workspace.evaluate(line, eval_path, line_no)
+        result = @workspace.evaluate(line, @eval_path, line_no)
       end
 
       set_last_value(result)
     end
 
-    private def eval_path
-      # We need to use differente path to distinguish source_location of method defined in the actual file and method defined in irb session.
-      if !defined?(@irb_path_existence) || @irb_path_existence[0] != irb_path
-        @irb_path_existence = [irb_path, File.exist?(irb_path)]
-      end
-      @irb_path_existence[1] ? "#{irb_path}(#{IRB.conf[:IRB_NAME]})" : irb_path
-    end
-
     def inspect_last_value # :nodoc:
       @inspect_method.inspect_value(@last_value)
     end

lib/irb/ext/loader.rb

@@ -98,13 +98,13 @@ def load_file(path, priv = nil)
 
     def old # :nodoc:
       back_io = @io
-      back_path = @irb_path
+      back_path = irb_path
       back_name = @irb_name
       back_scanner = @irb.scanner
       begin
         @io = FileInputMethod.new(path)
         @irb_name = File.basename(path)
-        @irb_path = path
+        self.irb_path = path
         @irb.signal_status(:IN_LOAD) do
           if back_io.kind_of?(FileInputMethod)
             @irb.eval_input
@@ -119,7 +119,7 @@ def old # :nodoc:
       ensure
         @io = back_io
         @irb_name = back_name
-        @irb_path = back_path
+        self.irb_path = back_path
         @irb.scanner = back_scanner
       end
     end

lib/irb/source_finder.rb

@@ -27,7 +27,7 @@ def file_content
 
       def colorized_content
         if !binary_file? && file_exist?
-          end_line = Source.find_end(file_content, @line)
+          end_line = find_end
           # To correctly colorize, we need to colorize full content and extract the relevant lines.
           colored = IRB::Color.colorize_code(file_content)
           colored.lines[@line - 1...end_line].join
@@ -36,9 +36,12 @@ def colorized_content
         end
       end
 
-      def self.find_end(code, first_line)
+      private
+
+      def find_end
         lex = RubyLex.new
-        lines = code.lines[(first_line - 1)..-1]
+        code = file_content
+        lines = code.lines[(@line - 1)..-1]
         tokens = RubyLex.ripper_lex_without_warning(lines.join)
         prev_tokens = []
 
@@ -49,10 +52,10 @@ def self.find_end(code, first_line)
           continue = lex.should_continue?(prev_tokens)
           syntax = lex.check_code_syntax(code, local_variables: [])
           if !continue && syntax == :valid
-            return first_line + lnum
+            return @line + lnum
           end
         end
-        first_line
+        @line
       end
     end
 

test/irb/test_context.rb

@@ -666,13 +666,16 @@ def test_lineno
         ], out)
     end
 
-    def test_eval_path
+    def test_irb_path_setter
       @context.irb_path = __FILE__
-      assert_equal("#{__FILE__}(irb)", @context.send(:eval_path))
+      assert_equal(__FILE__, @context.irb_path)
+      assert_equal("#{__FILE__}(irb)", @context.instance_variable_get(:@eval_path))
       @context.irb_path = 'file/does/not/exist'
-      assert_equal('file/does/not/exist', @context.send(:eval_path))
+      assert_equal('file/does/not/exist', @context.irb_path)
+      assert_equal('file/does/not/exist', @context.instance_variable_get(:@eval_path))
       @context.irb_path = "#{__FILE__}(irb)"
-      assert_equal("#{__FILE__}(irb)", @context.send(:eval_path))
+      assert_equal("#{__FILE__}(irb)", @context.irb_path)
+      assert_equal("#{__FILE__}(irb)", @context.instance_variable_get(:@eval_path))
     end
 
     def test_build_completor