Jasmine: Test that an object is an instance of a given class

If (for some reason that you don't want to ask yourself) you need to know all classes that define a method with a given name, you can do it like this:

def classes_defining_method(method_name)
  method_name = method_name.to_sym
  Objec...

Checking if a JavaScript value is of a given type can be very confusing:

• There are two operators typeof and instanceof which work very differently.
• JavaScript has some primitive types, like string literals, that are not objects (as oppose...

If you want to find out whether a Class object is directly inheriting from another class, use superclass:

ActiveRecord::RecordNotFound.super_class == ActiveRecord::ActiveRecordError # => true

To check if an...

rspec >= 3.1 brings a method and_wrap_original. It seems a bit complicated at first, but there are use cases where it helps to write precise tests. For example it allows to add expectations on objects that will only be created when your code is ...

The step definition below allows you to write:

Then I should see a link labeled "Foo"
But I should not see a link labeled "Bar"

Webrat

Then /^I should( not)? see a link labeled "([^"]*)"$/ do |negate, label|
  expectatio...

This can happen during development when classes without automatic reloading are pointing to classes with automatic reloading. E.g. some class in lib is calling Model.static_method.

Workaround A

Stop referencing autoloaded classes fro...

Spreewald now comes with a step that tests if a form field is visible:

Then the "Due date" field should be visible
But the "Author" field should not be visible

The step works by looking up the...

The goal is to get Jasmine specs running in a Rails project using Webpacker, with the browser based test runner. Should be easily adaptable to a pure Webpack setup.

Step 1: Install Jasmine

yarn...

This is an awful way to test whether a number is shown on the screen:

Then I should see "5"

It is awful because the step above is green for 5, 5123 and -51.

This step definition below makes sure this doesn't happen. You can use it like this...

Native promises have no methods to inspect their state.

You can use the promiseState function below to check whether a promise is fulfilled, rejected or still pendi...