1 files changed, 112 insertions, 0 deletions
diff --git a/spec/models/experiment_spec.rb b/spec/models/experiment_spec.rb
new file mode 100644
index 00000000000..64cd2da4621
--- /dev/null
+++ b/spec/models/experiment_spec.rb
@@ -0,0 +1,112 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Experiment do
+  subject { build(:experiment) }
+
+  describe 'associations' do
+    it { is_expected.to have_many(:experiment_users) }
+    it { is_expected.to have_many(:users) }
+    it { is_expected.to have_many(:control_group_users) }
+    it { is_expected.to have_many(:experimental_group_users) }
+
+    describe 'control_group_users and experimental_group_users' do
+      let(:experiment) { create(:experiment) }
+      let(:control_group_user) { build(:user) }
+      let(:experimental_group_user) { build(:user) }
+
+      before do
+        experiment.control_group_users << control_group_user
+        experiment.experimental_group_users << experimental_group_user
+      end
+
+      describe 'control_group_users' do
+        subject { experiment.control_group_users }
+
+        it { is_expected.to contain_exactly(control_group_user) }
+      end
+
+      describe 'experimental_group_users' do
+        subject { experiment.experimental_group_users }
+
+        it { is_expected.to contain_exactly(experimental_group_user) }
+      end
+    end
+  end
+
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:name) }
+    it { is_expected.to validate_uniqueness_of(:name) }
+    it { is_expected.to validate_length_of(:name).is_at_most(255) }
+  end
+
+  describe '.add_user' do
+    let(:name) { :experiment_key }
+    let(:user) { build(:user) }
+
+    let!(:experiment) { create(:experiment, name: name) }
+
+    subject { described_class.add_user(name, :control, user) }
+
+    describe 'creating a new experiment record' do
+      context 'an experiment with the provided name already exists' do
+        it 'does not create a new experiment record' do
+          expect { subject }.not_to change(Experiment, :count)
+        end
+      end
+
+      context 'an experiment with the provided name does not exist yet' do
+        let(:experiment) { nil }
+
+        it 'creates a new experiment record' do
+          expect { subject }.to change(Experiment, :count).by(1)
+        end
+      end
+    end
+
+    describe 'creating a new experiment_user record' do
+      context 'an experiment_user record for this experiment already exists' do
+        before do
+          subject
+        end
+
+        it 'does not create a new experiment_user record' do
+          expect { subject }.not_to change(ExperimentUser, :count)
+        end
+      end
+
+      context 'an experiment_user record for this experiment does not exist yet' do
+        it 'creates a new experiment_user record' do
+          expect { subject }.to change(ExperimentUser, :count).by(1)
+        end
+
+        it 'assigns the correct group_type to the experiment_user' do
+          expect { subject }.to change { experiment.control_group_users.count }.by(1)
+        end
+      end
+    end
+  end
+
+  describe '#add_control_user' do
+    let(:experiment) { create(:experiment) }
+    let(:user) { build(:user) }
+
+    subject { experiment.add_control_user(user) }
+
+    it 'creates a new experiment_user record and assigns the correct group_type' do
+      expect { subject }.to change { experiment.control_group_users.count }.by(1)
+    end
+  end
+
+  describe '#add_experimental_user' do
+    let(:experiment) { create(:experiment) }
+    let(:user) { build(:user) }
+
+    subject { experiment.add_experimental_user(user) }
+
+    it 'creates a new experiment_user record and assigns the correct group_type' do
+      expect { subject }.to change { experiment.experimental_group_users.count }.by(1)
+    end
+  end
+end