Fix failing spec

spec/marten/template/value_spec.cr

@@ -213,6 +213,21 @@ describe Marten::Template::Value do
       value["test_attr"].should eq Marten::Template::Value.from("hello")
     end
 
+    it "raises an unknown variable error if the attribute does not exist" do
+      value = Marten::Template::Value.from({"foo" => "bar", "test" => 42})
+      expect_raises(Marten::Template::Errors::UnknownVariable) { value["unknown"] }
+    end
+
+    it "raises an unknown variable error if the index does not exist for an array" do
+      value = Marten::Template::Value.from(["foo", "bar"])
+      expect_raises(Marten::Template::Errors::UnknownVariable) { value["4"] }
+    end
+
+    it "raises an unknown variable error if the index is not a number for an array" do
+      value = Marten::Template::Value.from(["foo", "bar"])
+      expect_raises(Marten::Template::Errors::UnknownVariable) { value["bad"] }
+    end
+
     it "raises an unknown variable error if the raw object does not allow attribute lookups" do
       value = Marten::Template::Value.from(42)
       expect_raises(Marten::Template::Errors::UnknownVariable) { value["unknown"] }

src/marten/template/value.cr

@@ -93,21 +93,28 @@ module Marten
       private def resolve_attribute(key)
         object = raw
 
+        attempt_attribute_resolution_after_failed_collection_lookup = false
+
         if object.responds_to?(:[]) && !object.is_a?(Array) && !object.is_a?(String) &&
            !object.is_a?(Marten::Template::Object)
           begin
             return object[key.to_s]
           rescue KeyError
+            attempt_attribute_resolution_after_failed_collection_lookup = true
           end
         elsif object.is_a?(Indexable) && !object.is_a?(Marten::Template::Object) && key.responds_to?(:to_i)
           begin
             return object[key.to_i]
           rescue ArgumentError | IndexError
+            attempt_attribute_resolution_after_failed_collection_lookup = true
           end
+        elsif object.responds_to?(:resolve_template_attribute)
+          return object.resolve_template_attribute(key.to_s)
         end
 
-        if object.responds_to?(:resolve_template_attribute)
-          return object.resolve_template_attribute(key.to_s)
+        if attempt_attribute_resolution_after_failed_collection_lookup
+          res = object.responds_to?(:resolve_template_attribute) ? object.resolve_template_attribute(key.to_s) : nil
+          return res if !res.nil?
         end
 
         raise Errors::UnknownVariable.new