Add basic tests for alias/data flow processing

test/tests/test_alias_processor.rb

+class AliasProcessorTests < Test::Unit::TestCase
+  def assert_alias expected, original
+    if RUBY_VERSION =~ /^1\.9/
+      original_sexp = Ruby19Parser.new.parse original
+      expected_sexp = Ruby19Parser.new.parse expected
+    else
+      original_sexp = RubyParser.new.parse original
+      expected_sexp = RubyParser.new.parse expected
+    end
+
+    processed_sexp = Brakeman::AliasProcessor.new.process_safely original_sexp
+    result = processed_sexp.last
+
+    assert_equal expected_sexp, result
+  end
+
+  def test_addition
+    assert_alias '10', <<-RUBY
+      x = 1 + 2 + 3
+      x += 4
+      x
+    RUBY
+  end
+
+  def test_simple_math
+    assert_alias '42', <<-RUBY
+      x = 8 * 5
+      y = 32 / 8
+      y -= 2
+      x += y
+      x
+    RUBY
+  end
+
+  def test_concatentation
+    assert_alias "'Hello world!'", <<-RUBY
+      x = "Hello"
+      y = x + " "
+      z = y + "world!"
+      z
+    RUBY
+  end
+
+  def test_string_append
+    assert_alias "'hello world'", <<-RUBY
+      x = ""
+      x << "hello" << " " << "world"
+      x
+    RUBY
+  end
+
+  def test_array_index
+    assert_alias "'cookie'", <<-RUBY
+      dessert = ["fruit", "pie", "ice cream"]
+      dessert << "cookie"
+      dessert[1] = "cake"
+      dessert[1]
+      index = 2
+      index = index + 1
+      dessert[index]
+    RUBY
+  end
+
+  def test_array_negative_index
+    assert_alias "'ice cream'", <<-RUBY
+      dessert = ["fruit", "pie", "ice cream"]
+      dessert << "cookie"
+      dessert[1] = "cake"
+      dessert[1]
+      index = -3
+      index = 1 + index
+      dessert[index]
+    RUBY
+  end
+
+
+  def test_array_append
+    assert_alias '[1, 2, 3]', <<-RUBY
+      x = [1]
+      x << 2 << 3
+      x
+    RUBY
+  end
+
+  def test_hash_index
+    assert_alias "'You say goodbye, I say :hello'", <<-RUBY
+      x = {:goodbye => "goodbye cruel world" }
+      x[:hello] = "hello world"
+      x.merge! :goodbye => "You say goodbye, I say :hello"
+      x[:goodbye]
+    RUBY
+  end
+
+  def test_obvious_if
+    assert_alias "'Yes!'", <<-RUBY
+      condition = true
+
+      if condition
+        x = "Yes!"
+      else
+        x = "No!"
+      end
+
+      x
+    RUBY
+  end
+
+  def test_if
+    assert_alias "'Awesome!' or 'Else awesome!'", <<-RUBY
+      if something
+        x = "Awesome!"
+      elsif something_else
+        x = "Else awesome!"
+      end
+
+      x
+    RUBY
+  end
+
+  def test_or_equal
+    assert_alias '10', <<-RUBY
+      x.y = 10
+      x.y ||= "not this!"
+      x.y
+    RUBY
+  end
+
+  def test_unknown_hash
+    assert_alias '1', <<-RUBY
+      some_hash[:x] = 1
+      some_hash[:x]
+    RUBY
+  end
+
+  def test_global
+    assert_alias '1', <<-RUBY
+      $x = 1
+      $x
+    RUBY
+  end
+
+  def test_class_var
+    assert_alias '1', <<-RUBY
+      @@x = 1
+      @@x
+    RUBY
+  end
+
+  def test_constant
+    assert_alias '1', <<-RUBY
+      X = 1
+      X
+    RUBY
+  end
+
+  def test_addition_chained
+    assert_alias 'y + 5', <<-RUBY
+    x = y + 2 + 3
+    x
+    RUBY
+  end
+end