Add tests for Node code locations

* test/-ext-/ast/test_ast.rb: Add tests for Node
  code locations. This file tests

  1. There are no Node whose code location is default
     value (#test_not_cared)

  2. There are no Node whose children's code locations
     exceed parent's code location (#test_ranges)

* ext/-test-/ast/ast.c, ext/-test-/ast/extconf.rb:
  Define AST module to help tests.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61859 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 132 insertions, 0 deletions

diff --git a/test/-ext-/ast/test_ast.rb b/test/-ext-/ast/test_ast.rb
new file mode 100644
index 0000000000..5f107480b1
--- /dev/null
+++ b/test/-ext-/ast/test_ast.rb
@@ -0,0 +1,132 @@
+# frozen_string_literal: false
+require 'test/unit'
+require "-test-/ast"
+
+module AST
+  class Node
+    class CodePosition
+      include Comparable
+      attr_reader :lineno, :column
+      def initialize(lineno, column)
+        @lineno = lineno
+        @column = column
+      end
+
+      def <=>(other)
+        case
+        when lineno < other.lineno
+          -1
+        when lineno == other.lineno
+          column <=> other.column
+        when lineno > other.lineno
+          1
+        end
+      end
+    end
+
+    def beg_pos
+      CodePosition.new(first_lineno, first_column)
+    end
+
+    def end_pos
+      CodePosition.new(last_lineno, last_column)
+    end
+
+    alias to_s inspect
+  end
+end
+
+class TestAst < Test::Unit::TestCase
+  class Helper
+    attr_reader :errors
+
+    def initialize(path)
+      @path = path
+      @errors = []
+      @debug = false
+    end
+
+    def validate_range
+      @errors = []
+      validate_range0(ast)
+
+      @errors.empty?
+    end
+
+    def validate_not_cared
+      @errors = []
+      validate_not_cared0(ast)
+
+      @errors.empty?
+    end
+
+    def ast
+      return @ast if defined?(@ast)
+      ast = AST.parse_file(@path)
+      raise "Syntax error: #{@path}" if ast.nil?
+      @ast = ast
+    end
+
+    private
+
+    def validate_range0(node)
+      beg_pos, end_pos = node.beg_pos, node.end_pos
+      children = node.children.compact
+
+      return true if children.empty?
+      # These NODE_D* has NODE_ARRAY as nd_next->nd_next whose last locations
+      # we can not update when item is appended.
+      return true if ["NODE_DSTR", "NODE_DXSTR", "NODE_DREGX", "NODE_DSYM"].include? node.type
+
+      min = children.map(&:beg_pos).min
+      max = children.map(&:end_pos).max
+
+      unless beg_pos <= min
+        @errors << { type: :min_validation_error, min: min, beg_pos: beg_pos, node: node }
+      end
+
+      unless max <= end_pos
+        @errors << { type: :max_validation_error, max: max, end_pos: end_pos, node: node }
+      end
+
+      p "#{node} => #{children}" if @debug
+
+      children.each do |child|
+        p child if @debug
+        validate_range0(child)
+      end
+    end
+
+    def validate_not_cared0(node)
+      beg_pos, end_pos = node.beg_pos, node.end_pos
+      children = node.children.compact
+
+      @errors << { type: :first_lineno, node: node } if beg_pos.lineno == 0
+      @errors << { type: :first_column, node: node } if beg_pos.column == -1
+      @errors << { type: :last_lineno,  node: node } if end_pos.lineno == 0
+      @errors << { type: :last_column,  node: node } if end_pos.column == -1
+
+      children.each {|c| validate_not_cared0(c) }
+    end
+  end
+
+  SRCDIR = File.expand_path("../../../..", __FILE__)
+
+  Dir.glob("#{SRCDIR}/test/**/*.rb").each do |path|
+    define_method("test_ranges:#{path}") do
+      helper = Helper.new(path)
+      helper.validate_range
+
+      assert_equal([], helper.errors)
+    end
+  end
+
+  Dir.glob("#{SRCDIR}/test/**/*.rb").each do |path|
+    define_method("test_not_cared:#{path}") do
+      helper = Helper.new(path)
+      helper.validate_not_cared
+
+      assert_equal([], helper.errors)
+    end
+  end
+end