Errors getting swallowed

controller.rb

class SettingsController < ApplicationController

  layout 'main', only: [:more]

  def edit
    @account = client.account
  end

  def edit
    @form = SettingsUpdate.new(account: client.account)
  end

  def update
    @form = SettingsUpdate.new(account_params.merge(account: client.account))

    if @form.save
      redirect_to edit_settings_path, notice: 'Your settings were successfully updated.'
    else
      flash.now[:error] = presented_errors
      render :edit
    end

  end

  def more
    @account = client.account
  end

  private

  def account_params
    params.permit(
      :store_name,
      :description,
      :contact_email,
    )
  end

  def presented_errors
    ErrorMessagesPresenter.new(@form.errors.messages).errors
  end

end

spec.rb

require 'rails_helper'

describe SettingsController do
  describe "#update" do

    let(:client) { Minitest::Mock.new }
    let(:account) { Minitest::Mock.new }

    before do
      mock(@controller).client.any_times { client }
      mock(client).account.any_times { account }
    end

    it "initializes a form with account params and the current account" do
      expected_arguments = { store_name: 'foo', account: account }
      mock(SettingsUpdate).new
      put :update, store_name: 'foo'
    end

  end
end