Add Wizards::Steps::MainEmail model

app/models/wizards/steps/main_email.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+#  Copyright (c) 2024, Schweizer Alpen-Club. This file is part of
+#  hitobito_sac_cas and licensed under the Affero General Public License version 3
+#  or later. See the COPYING file at the top-level directory or at
+#  https://github.com/hitobito/hitobito_sac_cas.
+
+class Wizards::Steps::MainEmail < Wizards::Step
+  include ValidatedEmail
+
+  attribute :email, :string
+
+  validates :email, presence: true
+  validate :ensure_email_available
+
+  # #email_changed? is used in `ValidatedEmail` to determine if the email
+  # should be validated. Here it should only be validated if the email is
+  # present.
+  def email_changed?
+    email.present?
+  end
+
+  def ensure_email_available
+    return if email.blank?
+
+    if Person.exists?(email: email)
+      errors.add(:email, I18n.t('activerecord.errors.models.person.attributes.email.taken'))
+    end
+  end
+end

spec/models/wizards/steps/main_email_spec.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+#
+#  Copyright (c) 2023, Schweizer Alpen-Club. This file is part of
+#  hitobito_sac_cas and licensed under the Affero General Public License version 3
+#  or later. See the COPYING file at the top-level directory or at
+#  https://github.com/hitobito/hitobito_sac_cas.
+
+require 'spec_helper'
+
+describe Wizards::Steps::MainEmail do
+  let(:params) { {} }
+  let(:wizard) { nil } # we don't need a wizard for the model specs
+  let(:subject) { described_class.new(wizard, **params) }
+
+  describe 'validations' do
+    context 'without email' do
+      it do
+        is_expected.not_to be_valid
+        expect(subject.errors[:email].count).to eq 1
+      end
+    end
+
+    context 'with invalid email' do
+      before { allow(Truemail).to receive(:valid?).and_return(false) }
+
+      it do
+        is_expected.not_to be_valid
+        expect(subject.errors[:email].count).to eq 1
+      end
+    end
+
+    context 'with valid email' do
+      let(:params) { { email: 'foo@bar.ch' } }
+
+      it { is_expected.to be_valid }
+
+      context 'when email is already taken' do
+        before { Fabricate(:person, email: params[:email]) }
+
+        it do
+          is_expected.not_to be_valid
+          expect(subject.errors[:email].count).to eq 1
+        end
+
+      end
+    end
+  end
+end