```ruby
require 'spec_helper'

describe VolunteerOp do
  it 'must have a title' do
    v = VolunteerOp.new(title:'')
    expect(v).to have(1).errors_on(:title)
  end

  it 'must have a description' do
    v = VolunteerOp.new(description:'')
    expect(v).to have(1).errors_on(:description)
  end

  it 'must not be created without an organisation' do
    v = VolunteerOp.new(organisation_id:nil)
    expect(v).to have(1).error_on(:organisation_id)
  end
end```

Fix deprecation warnings about volop model spec
user
```ruby
require 'spec_helper'

describe VolunteerOp do
  it 'must have a title' do
    v = VolunteerOp.new(title:'')
    v.valid?
    expect(v.errors[:title].size).to eq(1)
  end

  it 'must have a description' do
    v = VolunteerOp.new(description:'')
    v.valid?
    expect(v.errors[:description].size).to eq(1)
  end

  it 'must not be created without an organisation' do
    v = VolunteerOp.new(organisation_id:nil)
    v.valid?
    expect(v.errors[:organisation_id].size).to eq(1)
  end
end
```
assistant