Merge pull request #241 from Shopify/i18n-error

Add I18n syntax error translation

lib/liquid.rb

@@ -48,6 +48,7 @@ end
 require "liquid/version"
 require 'liquid/lexer'
 require 'liquid/parser'
+require 'liquid/i18n'
 require 'liquid/drop'
 require 'liquid/extensions'
 require 'liquid/errors'

lib/liquid/block.rb

@@ -41,7 +41,7 @@ module Liquid
               unknown_tag($1, $2, tokens)
             end
           else
-            raise SyntaxError, "Tag '#{token}' was not properly terminated with regexp: #{TagEnd.inspect} "
+            raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination", :token => token, :tag_end => TagEnd.inspect))
           end
         when IsVariable
           new_var = create_variable(token)
@@ -80,11 +80,14 @@ module Liquid
     def unknown_tag(tag, params, tokens)
       case tag
       when 'else'
-        raise SyntaxError, "#{block_name} tag does not expect else tag"
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_else", 
+                                                 :block_name => block_name))
       when 'end'
-        raise SyntaxError, "'end' is not a valid delimiter for #{block_name} tags. use #{block_delimiter}"
+        raise SyntaxError.new(options[:locale].t("errors.syntax.invalid_delimiter", 
+                                                 :block_name => block_name, 
+                                                 :block_delimiter => block_delimiter))
       else
-        raise SyntaxError, "Unknown tag '#{tag}'"
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag", :tag => tag))
       end
     end
 
@@ -100,7 +103,7 @@ module Liquid
       token.scan(ContentOfVariable) do |content|
         return Variable.new(content.first, @options)
       end
-      raise SyntaxError.new("Variable '#{token}' was not properly terminated with regexp: #{VariableEnd.inspect} ")
+      raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination", :token => token, :tag_end => TagEnd.inspect))
     end
 
     def render(context)
@@ -110,7 +113,7 @@ module Liquid
     protected
 
     def assert_missing_delimitation!
-      raise SyntaxError.new("#{block_name} tag was never closed")
+      raise SyntaxError.new(options[:locale].t("errors.syntax.tag_never_closed", :block_name => block_name))
     end
 
     def render_all(list, context)

lib/liquid/htmltags.rb

@@ -11,7 +11,7 @@ module Liquid
           @attributes[key] = value
         end
       else
-        raise SyntaxError.new("Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row"))
       end
 
       super

lib/liquid/i18n.rb

@@ -0,0 +1,39 @@
+require 'yaml'
+
+module Liquid
+  class I18n
+    DEFAULT_LOCALE = File.join(File.expand_path(File.dirname(__FILE__)), "locales", "en.yml")
+
+    class TranslationError < StandardError
+    end
+    
+    attr_reader :path
+
+    def initialize(path = DEFAULT_LOCALE)
+      @path = path
+    end
+
+    def translate(name, vars = {})
+      interpolate(deep_fetch_translation(name), vars)
+    end
+    alias_method :t, :translate
+
+    def locale
+      @locale ||= YAML.load_file(@path)
+    end
+
+    private
+    def interpolate(name, vars)
+      name.gsub(/%{(\w+)}/) {
+        raise TranslationError, "Undefined key #{$1} for interpolation in translation #{name}"  unless vars[$1.to_sym]
+        "#{vars[$1.to_sym]}"
+      }
+    end
+
+    def deep_fetch_translation(name)
+      name.split('.').reduce(locale) do |level, cur|
+        level[cur] or raise TranslationError, "Translation for #{name} does not exist in locale #{path}"
+      end
+    end
+  end
+end

lib/liquid/locales/en.yml

@@ -0,0 +1,21 @@
+---
+  errors:
+    syntax:
+      assign: "Syntax Error in 'assign' - Valid syntax: assign [var] = [source]"
+      capture: "Syntax Error in 'capture' - Valid syntax: capture [var]"
+      case: "Syntax Error in 'case' - Valid syntax: case [condition]"
+      case_invalid_when: "Syntax Error in tag 'case' - Valid when condition: {% when [condition] [or condition2...] %}"
+      case_invalid_else: "Syntax Error in tag 'case' - Valid else condition: {% else %} (no parameters) "
+      cycle: "Syntax Error in 'cycle' - Valid syntax: cycle [name :] var [, var2, var3 ...]"
+      for: "Syntax Error in 'for loop' - Valid syntax: for [item] in [collection]"
+      for_invalid_in: "For loops require an 'in' clause"
+      for_invalid_attribute: "Invalid attribute in for loop. Valid attributes are limit and offset"
+      if: "Syntax Error in tag 'if' - Valid syntax: if [expression]"
+      include: "Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]"
+      unknown_tag: "Unknown tag '%{tag}'"
+      invalid_delimiter: "'end' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
+      unexpected_else: "%{block_name} tag does not expect else tag"
+      tag_termination: "Tag '%{token}' was not properly terminated with regexp: %{tag_end}"
+      tag_never_closed: "'%{block_name}' tag was never closed"
+      meta_syntax_error: "Liquid syntax error: #{e.message}"
+      table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"

lib/liquid/tags/assign.rb

@@ -16,7 +16,7 @@ module Liquid
         @to = $1
         @from = Variable.new($2)
       else
-        raise SyntaxError.new("Syntax Error in 'assign' - Valid syntax: assign [var] = [source]")
+        raise SyntaxError.new options[:locale].t("errors.syntax.assign")
       end
 
       super

lib/liquid/tags/capture.rb

@@ -18,7 +18,7 @@ module Liquid
       if markup =~ Syntax
         @to = $1
       else
-        raise SyntaxError.new("Syntax Error in 'capture' - Valid syntax: capture [var]")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
       end
 
       super

lib/liquid/tags/case.rb

@@ -9,7 +9,7 @@ module Liquid
       if markup =~ Syntax
         @left = $1
       else
-        raise SyntaxError.new("Syntax Error in tag 'case' - Valid syntax: case [condition]")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case"))
       end
 
       super
@@ -50,7 +50,7 @@ module Liquid
       while markup
         # Create a new nodelist and assign it to the new block
         if not markup =~ WhenSyntax
-          raise SyntaxError.new("Syntax Error in tag 'case' - Valid when condition: {% when [condition] [or condition2...] %} ")
+          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when"))
         end
 
         markup = $2
@@ -63,7 +63,7 @@ module Liquid
 
     def record_else_condition(markup)
       if not markup.strip.empty?
-        raise SyntaxError.new("Syntax Error in tag 'case' - Valid else condition: {% else %} (no parameters) ")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else"))
       end
 
       block = ElseCondition.new

lib/liquid/tags/cycle.rb

@@ -24,7 +24,7 @@ module Liquid
         @variables = variables_from_string(markup)
         @name = "'#{@variables.to_s}'"
       else
-        raise SyntaxError.new("Syntax Error in 'cycle' - Valid syntax: cycle [name :] var [, var2, var3 ...]")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle"))
       end
       super
     end

lib/liquid/tags/for.rb

@@ -128,14 +128,14 @@ module Liquid
           @attributes[key] = value
         end
       else
-        raise SyntaxError.new("Syntax Error in 'for loop' - Valid syntax: for [item] in [collection]")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.for"))
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError, "For loops require an 'in' clause" unless p.id?('in')
+      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in"))  unless p.id?('in')
       @collection_name = p.expression
       @name = "#{@variable_name}-#{@collection_name}"
       @reversed = p.id?('reversed')
@@ -143,7 +143,7 @@ module Liquid
       @attributes = {}
       while p.look(:id) && p.look(:colon, 1)
         unless attribute = p.id?('limit') || p.id?('offset')
-          raise SyntaxError, "Invalid attribute in for loop. Valid attributes are limit and offset"
+          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute"))
         end
         p.consume
         val = p.expression

lib/liquid/tags/if.rb

@@ -10,7 +10,6 @@ module Liquid
   #    There are {% if count < 5 %} less {% else %} more {% endif %} items than you need.
   #
   class If < Block
-    SyntaxHelp = "Syntax Error in tag 'if' - Valid syntax: if [expression]"
     Syntax = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/o
     ExpressionsAndOperators = /(?:\b(?:\s?and\s?|\s?or\s?)\b|(?:\s*(?!\b(?:\s?and\s?|\s?or\s?)\b)(?:#{QuotedFragment}|\S+)\s*)+)/o
 
@@ -54,14 +53,14 @@ module Liquid
 
       def lax_parse(markup)
         expressions = markup.scan(ExpressionsAndOperators).reverse
-        raise(SyntaxError, SyntaxHelp) unless expressions.shift =~ Syntax
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if"))) unless expressions.shift =~ Syntax
 
         condition = Condition.new($1, $2, $3)
 
         while not expressions.empty?
           operator = (expressions.shift).to_s.strip
 
-          raise(SyntaxError, SyntaxHelp) unless expressions.shift.to_s =~ Syntax
+          raise(SyntaxError.new(options[:locale].t("errors.syntax.if"))) unless expressions.shift.to_s =~ Syntax
 
           new_condition = Condition.new($1, $2, $3)
           new_condition.send(operator.to_sym, condition)

lib/liquid/tags/include.rb

@@ -29,7 +29,7 @@ module Liquid
         end
 
       else
-        raise SyntaxError.new("Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.include"))
       end
 
       super

lib/liquid/template.rb

@@ -14,6 +14,10 @@ module Liquid
   #   template.render('user_name' => 'bob')
   #
   class Template
+    DEFAULT_OPTIONS = {
+      :locale => I18n.new
+    }
+
     attr_accessor :root, :resource_limits
     @@file_system = BlankFileSystem.new
 
@@ -68,7 +72,7 @@ module Liquid
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
-      @root = Document.new(tokenize(source), options)
+      @root = Document.new(tokenize(source), DEFAULT_OPTIONS.merge(options))
       @warnings = nil
       self
     end
@@ -119,7 +123,7 @@ module Liquid
       when nil
         Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits)
       else
-        raise ArgumentError, "Expect Hash or Liquid::Context as parameter"
+        raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
       end
 
       case args.last

test/fixtures/en_locale.yml

@@ -0,0 +1,9 @@
+---
+  simple: "less is more"
+  whatever: "something %{something}"
+  errors:
+    i18n:
+      undefined_interpolation: "undefined key %{key}"
+      unknown_translation: "translation '%{name}' wasn't found"
+    syntax:
+      oops: "something wasn't right"

test/liquid/assign_test.rb

@@ -18,4 +18,10 @@ class AssignTest < Test::Unit::TestCase
                            '{% assign foo = values | split: "," %}.{{ foo[1] }}.',
                            'values' => "foo,bar,baz")
   end
+
+  def test_assign_syntax_error
+    assert_match_syntax_error(/assign/,
+                       '{% assign foo not values %}.',
+                       'values' => "foo,bar,baz")
+  end
 end # AssignTest

test/liquid/i18n_test.rb

@@ -0,0 +1,37 @@
+require 'test_helper'
+
+class I18nTest < Test::Unit::TestCase
+  include Liquid
+
+  def setup
+    @i18n = I18n.new(fixture("en_locale.yml"))
+  end
+
+  def test_simple_translate_string
+    assert_equal "less is more", @i18n.translate("simple")
+  end
+
+  def test_nested_translate_string
+    assert_equal "something wasn't right", @i18n.translate("errors.syntax.oops")
+  end
+
+  def test_single_string_interpolation
+    assert_equal "something different", @i18n.translate("whatever", :something => "different")
+  end
+
+  def test_raises_translation_error_on_undefined_interpolation_key
+    assert_raise I18n::TranslationError do
+      @i18n.translate("whatever", :oopstypos => "yes")
+    end
+  end
+  
+  def test_raises_unknown_translation
+    assert_raise I18n::TranslationError do
+      @i18n.translate("doesnt_exist")
+    end
+  end
+
+  def test_sets_default_path_to_en
+    assert_equal I18n::DEFAULT_LOCALE, I18n.new.path
+  end
+end

test/liquid/template_test.rb

@@ -143,4 +143,18 @@ class TemplateTest < Test::Unit::TestCase
     assert_equal 'bar', t.parse('{{bar}}').render(drop)
     assert_equal 'haha', t.parse("{{baz}}").render(drop)
   end
-end # TemplateTest
+
+  def test_sets_default_localization_in_document
+    t = Template.new
+    t.parse('')
+    assert_instance_of I18n, t.root.options[:locale]
+  end
+
+  def test_sets_default_localization_in_context_with_quick_initialization
+    t = Template.new
+    t.parse('{{foo}}', :locale => I18n.new(fixture("en_locale.yml")))
+
+    assert_instance_of I18n, t.root.options[:locale]
+    assert_equal fixture("en_locale.yml"), t.root.options[:locale].path
+  end
+end

test/test_helper.rb

@@ -7,7 +7,9 @@ begin
 rescue LoadError
   puts "Couldn't load ruby-debug. gem install ruby-debug if you need it."
 end
-require File.join(File.dirname(__FILE__), '..', 'lib', 'liquid')
+
+$:.unshift(File.join(File.expand_path(File.dirname(__FILE__)), '..', 'lib'))
+require 'liquid.rb'
 
 mode = :strict
 if env_mode = ENV['LIQUID_PARSER_MODE']
@@ -19,6 +21,12 @@ Liquid::Template.error_mode = mode
 
 module Test
   module Unit
+    class TestCase
+      def fixture(name)
+        File.join(File.expand_path(File.dirname(__FILE__)), "fixtures", name)
+      end
+    end
+
     module Assertions
       include Liquid
 
@@ -32,6 +40,13 @@ module Test
         assert_match expected, Template.parse(template).render(assigns)
       end
 
+      def assert_match_syntax_error(match, template, registers = {})
+        exception = assert_raise(Liquid::SyntaxError) {
+          Template.parse(template).render(assigns)
+        }
+        assert_match match, exception.message
+      end
+
       def with_error_mode(mode)
         old_mode = Liquid::Template.error_mode
         Liquid::Template.error_mode = mode