Add support for strict mode feature

Author: gogaz

lib/ruby-handlebars.rb

@@ -17,8 +17,8 @@ def initialize()
       set_escaper
     end
 
-    def compile(template)
-      Template.new(self, template_to_ast(template))
+    def compile(template, **options)
+      Template.new(self, template_to_ast(template), **options)
     end
 
     def register_helper(name, &fn)

lib/ruby-handlebars/context.rb

@@ -1,8 +1,12 @@
 module Handlebars
   class Context
-    def initialize(hbs, data)
+    class AttributeNotFoundError < StandardError
+    end
+
+    def initialize(hbs, data, **options)
       @hbs = hbs
       @data = data
+      @options = options || {}
     end
 
     def get(path)
@@ -75,6 +79,8 @@ def get_attribute(item, attribute)
       if item.respond_to?(sym_attr)
         return item.send(sym_attr)
       end
+
+      raise AttributeNotFoundError if @options[:strict]
     end
   end
 end

lib/ruby-handlebars/template.rb

@@ -2,13 +2,14 @@
 
 module Handlebars
   class Template
-    def initialize(hbs, ast)
+    def initialize(hbs, ast, **options)
       @hbs = hbs
       @ast = ast
+      @options = options || {}
     end
 
     def call(args = nil)
-      ctx = Context.new(@hbs, args)
+      ctx = Context.new(@hbs, args, **@options)
 
       @ast.eval(ctx)
     end

spec/handlebars_spec.rb

@@ -6,8 +6,8 @@
 describe Handlebars::Handlebars do
   let(:hbs) {Handlebars::Handlebars.new}
 
-  def evaluate(template, args = {})
-    hbs.compile(template).call(args)
+  def evaluate(template, args = {}, **compiling_options)
+    hbs.compile(template, **compiling_options).call(args)
   end
 
   context 'evaluating' do
@@ -51,6 +51,12 @@ def evaluate(template, args = {})
       expect(evaluate('Hello {{first-name}}', double("first-name": 'world'))).to eq('Hello world')
     end
 
+    context 'strict mode' do
+      it 'raises an error' do
+        expect{evaluate('Hello {{you}}', {}, strict: true)}.to raise_error(Handlebars::Context::AttributeNotFoundError)
+      end
+    end
+
     context 'partials' do
       it 'simple' do
         hbs.register_partial('plic', "Plic")
@@ -71,7 +77,7 @@ def evaluate(template, args = {})
         hbs.register_partial('brackets', "[{{name}}]")
         expect(evaluate("Hello {{> brackets}}", {name: 'world'})).to eq("Hello [world]")
       end
-      
+
       it 'with a string argument' do
         hbs.register_partial('with_args', "[{{name}}]")
         expect(evaluate("Hello {{> with_args name='jon'}}")).to eq("Hello [jon]")