Add parser tests

lib/liquid/parser.rb

@@ -40,12 +40,6 @@ module Liquid
       token.contents
     end
 
-    def cur_token()
-      tok = @tokens[@p]
-      raise SyntaxError, 'Expected more input.' unless tok
-      tok
-    end
-
     def look(type, ahead = 0)
       tok = @tokens[@p + ahead]
       return false unless tok
@@ -55,7 +49,7 @@ module Liquid
     # === General Liquid parsing functions ===
 
     def expression
-      token = cur_token
+      token = @tokens[@p]
       if token.type == :id
         variable_signature
       elsif [:string, :integer, :float].include? token.type

test/liquid/parser_test.rb

@@ -0,0 +1,74 @@
+require 'test_helper'
+
+class ParserTest < Test::Unit::TestCase
+  include Liquid
+
+  def test_consume
+    p = Parser.new("wat: 7")
+    assert_equal 'wat', p.consume(:id)
+    assert_equal ':', p.consume(:colon)
+    assert_equal '7', p.consume(:integer)
+  end
+
+  def test_jump
+    p = Parser.new("wat: 7")
+    p.jump(2)
+    assert_equal '7', p.consume(:integer)
+  end
+
+  def test_consume?
+    p = Parser.new("wat: 7")
+    assert_equal 'wat', p.consume?(:id)
+    assert_equal false, p.consume?(:dot)
+    assert_equal ':', p.consume(:colon)
+    assert_equal '7', p.consume?(:integer)
+  end
+
+  def test_id?
+    p = Parser.new("wat 6 Peter Hegemon")
+    assert_equal 'wat', p.id?('wat')
+    assert_equal false, p.id?('endgame')
+    assert_equal '6', p.consume(:integer)
+    assert_equal 'Peter', p.id?('Peter')
+    assert_equal false, p.id?('Achilles')
+  end
+
+  def test_look
+    p = Parser.new("wat 6 Peter Hegemon")
+    assert_equal true, p.look(:id)
+    assert_equal 'wat', p.consume(:id)
+    assert_equal false, p.look(:float)
+    assert_equal true, p.look(:integer)
+    assert_equal true, p.look(:id, 1)
+    assert_equal false, p.look(:float, 1)
+  end
+
+  def test_expressions
+    p = Parser.new("hi.there hi[5].! hi.there.bob")
+    assert_equal 'hi.there', p.expression
+    assert_equal 'hi[5].!', p.expression
+    assert_equal 'hi.there.bob', p.expression
+
+    p = Parser.new("567 6.0 'lol' \"wut\"")
+    assert_equal '567', p.expression
+    assert_equal '6.0', p.expression
+    assert_equal "'lol'", p.expression
+    assert_equal '"wut"', p.expression
+  end
+
+  def test_arguments
+    p = Parser.new("filter: hi.there[5], keyarg: 7")
+    assert_equal 'filter', p.consume(:id)
+    assert_equal ':', p.consume(:colon)
+    assert_equal 'hi.there[5]', p.argument
+    assert_equal ',', p.consume(:comma)
+    assert_equal 'keyarg: 7', p.argument
+  end
+
+  def test_invalid_expression
+    assert_raises(SyntaxError) do
+      p = Parser.new("==")
+      p.expression
+    end
+  end
+end