give hints for NameErrors

lib/better_errors/raised_exception.rb

@@ -65,7 +65,8 @@ def massage_syntax_error
     end
 
     def setup_hint
-      if exception.is_a?(NoMethodError)
+      case exception
+      when NoMethodError
         matches = /\Aundefined method `([^']+)' for ([^:]+):(\w+)\z/.match(message)
         method = matches[1]
         val = matches[2]
@@ -76,6 +77,12 @@ def setup_hint
         else
           @hint = "`#{method}` is being called on a `#{klass}`, which probably isn't the type you were expecting."
         end
+      when NameError
+        matches = /\Aundefined local variable or method `([^']+)' for/.match(message)
+        if matches
+          method_or_var = matches[1]
+          @hint = "`#{method_or_var}` is probably misspelled."
+        end
       end
     end
   end

spec/better_errors/raised_exception_spec.rb

@@ -69,6 +69,19 @@ module BetterErrors
       end
     end
 
+    context "when the exception is a NameError" do
+      let(:exception) {
+        begin
+          foo
+        rescue NameError => e
+          e
+        end
+      }
+
+      its(:type) { should == NameError }
+      its(:hint) { should == "`foo` is probably misspelled." }
+    end
+
     context "when the exception is a NoMethodError" do
       let(:exception) {
         begin