[ruby/prism] Location#slice_lines, Node#slice_lines

ruby/prism@9b61f6fdb3

lib/prism/parse_result.rb

@@ -45,6 +45,12 @@ def line_start(byte_offset)
       offsets[find_line(byte_offset)]
     end
 
+    # Returns the byte offset of the end of the line corresponding to the given
+    # byte offset.
+    def line_end(byte_offset)
+      offsets[find_line(byte_offset) + 1] || source.bytesize
+    end
+
     # Return the column number for the given byte offset.
     def column(byte_offset)
       byte_offset - line_start(byte_offset)
@@ -176,6 +182,15 @@ def slice
       source.slice(start_offset, length)
     end
 
+    # The source code that this location represents starting from the beginning
+    # of the line that this location starts on to the end of the line that this
+    # location ends on.
+    def slice_lines
+      line_start = source.line_start(start_offset)
+      line_end = source.line_end(end_offset)
+      source.slice(line_start, line_end - line_start)
+    end
+
     # The character offset from the beginning of the source where this location
     # starts.
     def start_character_offset

prism/templates/lib/prism/node.rb.erb

@@ -45,6 +45,13 @@ module Prism
       location.slice
     end
 
+    # Slice the location of the node from the source, starting at the beginning
+    # of the line that the location starts on, ending at the end of the line
+    # that the location ends on.
+    def slice_lines
+      location.slice_lines
+    end
+
     # Similar to inspect, but respects the current level of indentation given by
     # the pretty print object.
     def pretty_print(q)

test/prism/ruby_api_test.rb

@@ -209,6 +209,13 @@ def test_location_chop
       assert_equal "", location.slice
     end
 
+    def test_location_slice_lines
+      result = Prism.parse("\nprivate def foo\nend\n")
+      method = result.value.statements.body.first.arguments.arguments.first
+
+      assert_equal "private def foo\nend\n", method.slice_lines
+    end
+
     def test_heredoc?
       refute parse_expression("\"foo\"").heredoc?
       refute parse_expression("\"foo \#{1}\"").heredoc?