# RSpec::ActiveModel::Mocks [![RSpec CI](https://github.com/rspec/rspec-activemodel-mocks/actions/workflows/ci.yml/badge.svg)](https://github.com/rspec/rspec-activemodel-mocks/actions/workflows/ci.yml)

RSpec::ActiveModel::Mocks provides tools for testing `ActiveModel` classes.

    mock_model(Person, name: "Fred")

## Install

Add this line to your application's gemfile:

    gem 'rspec-activemodel-mocks'

And then execute:

    $ bundle

To finish the installation and start using `stub_model` and `mock_model`, require the
following file in your `spec_helper.rb` or `rails_helper.rb`.

    require 'rspec/active_model/mocks'

## Usage

### Mock

Creates a test double representing `string_or_model_class` with common
ActiveModel methods stubbed out. Additional methods may be easily stubbed
(via `add_stubs`) if `stubs` is passed. This is most useful for impersonating
models that don't exist yet.

ActiveModel methods, plus `new_record?`, are stubbed out implicitly.
`new_record?` returns the inverse of `persisted?`, and is present only for
compatibility with extension frameworks that have yet to update themselves to
the ActiveModel API (which declares `persisted?`, not `new_record?`).

`string_or_model_class` can be any of:

  * A String representing a Class that does not exist
  * A String representing a Class that extends `ActiveModel::Naming`
  * A Class that extends `ActiveModel::Naming`

### Stub

Creates an instance of `Model` with `to_param` stubbed using a generated value
that is unique to each object. If `Model` is an `ActiveRecord` model, it is
prohibited from accessing the database.

For each key in `stubs`, if the model has a matching attribute (determined by
`respond_to?`) it is simply assigned the submitted values.  If the model does
not have a matching attribute, the key/value pair is assigned as a stub return
value using RSpec's mocking/stubbing framework.

`persisted?` is overridden to return the result of `!id.nil?` This means that
by default `persisted?` will return true. If you want the object to behave as a
new record, sending it `as_new_record` will set the id to nil. You can also
explicitly set `:id => nil`, in which case `persisted?` will return false, but
using `as_new_record` makes the example a bit more descriptive.

While you can use `stub_model` in any example (model, view, controller,
helper), it is especially useful in view examples, which are inherently more
state-based than interaction-based.

    stub_model(Person)
    stub_model(Person).as_new_record
    stub_model(Person, :to_param => 37)
    stub_model(Person) {|person| person.first_name = "David"}