Empty rspec fails when I add this custom validation to my User model

I have a user model, if I add this custom validation my empty rspec test fails:

validate :password_complexity 

def password_complexity
    if !password.blank?
        errors.add(:password, "must contain a upper case character") if password.match(/[A-Z]/)
    end
end

Rspec:

require 'rails_helper'

RSpec.describe User, type: :model do

end

I run rspec spec/models/user_spec.rb and I get:

/Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/validations.rb:79:in raise_record_invalid': Validation failed: Password must contain a upper case character, Password must contain a lower case character (ActiveRecord::RecordInvalid) from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/validations.rb:43:in save!' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/attribute_methods/dirty.rb:29:in save!' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/transactions.rb:291:in block in save!' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/transactions.rb:351:in block in with_transaction_returning_status' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in transaction' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in transaction' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/transactions.rb:348:in with_transaction_returning_status' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/transactions.rb:291:in save!' from /Users/blank/dev/gitserver/myapp/myappweb/app/models/user.rb:74:in create_from_signup!' from /Users/blank/dev/gitserver/myapp/myappweb/app/services/account_service.rb:16:in block in create' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in block in transaction' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/transaction.rb:184:in within_new_transaction' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in transaction' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in transaction' from /Users/blank/dev/gitserver/myapp/myappweb/app/services/account_service.rb:11:in create' from /Users/blank/dev/gitserver/myapp/myappweb/db/seeds.rb:172:in <top (required)>' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in load' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in block in load' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in load_dependency' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in load' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/railties-4.2.5/lib/rails/engine.rb:547:in load_seed' from /Users/blank/dev/gitserver/myapp/myappweb/spec/spec_helper.rb:24:in block (2 levels) in <top (required)>' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/example.rb:424:in instance_exec' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/example.rb:424:in instance_exec' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/hooks.rb:357:in run' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/configuration.rb:1724:in block in run_hooks_with' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/configuration.rb:1724:in each' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/configuration.rb:1724:in run_hooks_with' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/configuration.rb:1679:in with_suite_hooks' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/runner.rb:114:in block in run_specs' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/reporter.rb:77:in report' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/runner.rb:113:in run_specs' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/runner.rb:89:in run' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/runner.rb:73:in run' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/lib/rspec/core/runner.rb:41:in invoke' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/gems/rspec-core-3.4.1/exe/rspec:4:in <top (required)>' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/bin/rspec:22:inload' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/bin/rspec:22:in <main>' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/bin/ruby_executable_hooks:15:in eval' from /Users/blank/.rvm/gems/ruby-2.3.3@myapp/bin/ruby_executable_hooks:15:in `'

Why is this happening? If I remove that custom validation, it runs fine.

My model is:

class User < ActiveRecord::Base
    has_secure_password 

  belongs_to :account

    validates :email, uniqueness: { scope: :account_id }
    validates_presence_of :email
    validates_presence_of :password, :password_confirmation, on: :create

    validates_length_of :password, :minimum => 8, :maximum => 32, :allow_blank => false
    #validate :password_complexity 


    def password_complexity
        if !password.blank?
            errors.add(:password, "must contain a upper case character") unless password.match(/[A-Z]/)
        end
    end
end