class ExpectedParameterMissing
Ruby on Rails 8.1.2
Since v8.0.4Available in: v8.0.4 v8.1.2
Raised from expect! when an expected parameter is missing or is of an incompatible type.
params = ActionController::Parameters.new(a: {}) params.expect!(:a) # => ActionController::ExpectedParameterMissing: param is missing or the value is empty or invalid: a