Add edge cases tests for Profitable metrics and calculations

Co-authored-by: jaracursorsh <jaracursorsh@mitomail.com>

Author: cursoragent

test/profitable/edge_cases_test.rb

@@ -0,0 +1,146 @@
+# frozen_string_literal: true
+require "test_helper"
+
+class EdgeCasesTest < Minitest::Test
+  def setup
+    super
+    @customer = Pay::Customer.create!(processor: "stripe")
+  end
+
+  def create_subscription(attrs = {})
+    defaults = {
+      customer: @customer,
+      processor: "stripe",
+      status: "active",
+      quantity: 1,
+      current_period_start: Time.now - 15.days,
+      current_period_end: Time.now + 15.days,
+      data: { "subscription_items" => [{ "price" => { "unit_amount" => 1000, "recurring" => { "interval" => "month", "interval_count" => 1 } } }] }
+    }
+    Pay::Subscription.create!(defaults.merge(attrs))
+  end
+
+  def test_estimated_valuation_clamps_multiplier_bounds
+    create_subscription # mrr 1000, arr 12000 cents
+
+    # Below lower bound -> clamp to 0.1x
+    v = Profitable.estimated_valuation(at: "0x")
+    assert_equal (12_000 * 0.1).round, v
+
+    # Above upper bound -> clamp to 100x
+    v = Profitable.estimated_valuation(at: "200x")
+    assert_equal (12_000 * 100).round, v
+
+    # Invalid type -> default 3x
+    v = Profitable.estimated_valuation(at: :wtf)
+    assert_equal (12_000 * 3).round, v
+  end
+
+  def test_time_to_next_mrr_milestone_no_more_milestones
+    # Set current mrr to highest milestone or beyond
+    Profitable.stub(:mrr, Profitable::NumericResult.new(100_000_000 * 100)) do
+      msg = Profitable.time_to_next_mrr_milestone
+      assert_match /Congratulations!/, msg
+    end
+  end
+
+  def test_time_to_next_mrr_milestone_unable_without_positive_growth
+    Profitable.stub(:mrr, Profitable::NumericResult.new(1_000 * 100)) do
+      Profitable.stub(:calculate_mrr_growth_rate, 0) do
+        msg = Profitable.time_to_next_mrr_milestone
+        assert_match /Unable to calculate/, msg
+      end
+      Profitable.stub(:calculate_mrr_growth_rate, -10) do
+        msg = Profitable.time_to_next_mrr_milestone
+        assert_match /Unable to calculate/, msg
+      end
+    end
+  end
+
+  def test_recurring_revenue_percentage_zero_when_no_total_revenue
+    assert_equal 0, Profitable.recurring_revenue_percentage(in_the_last: 30.days)
+  end
+
+  def test_churn_is_zero_when_no_subscribers_at_start
+    assert_equal 0, Profitable.churn(in_the_last: 30.days)
+  end
+
+  def test_new_mrr_counts_subscriptions_created_at_period_start
+    start = 10.days
+    t = Time.now
+    Timecop.freeze(t - start) do
+      # created exactly at start boundary (inclusive)
+      create_subscription(created_at: t - start)
+    end
+    # for newly created at start, prorated days should be full period
+    val = Profitable.new_mrr(in_the_last: start)
+    assert_operator val, :>=, 0
+  end
+
+  def test_mrr_at_includes_subscriptions_created_at_date
+    t = Time.now
+    Timecop.freeze(t - 1.day) do
+      create_subscription(created_at: t - 1.day)
+    end
+    # created_at == date should be included
+    val = Profitable.send(:calculate_mrr_at, t - 1.day)
+    assert_operator val, :>, 0
+  end
+
+  def test_churned_mrr_ignores_subscriptions_ending_in_future
+    Timecop.freeze(Time.now - 10.days) do
+      create_subscription
+    end
+    sub = Pay::Subscription.last
+    sub.update!(status: "canceled", ends_at: Time.now + 10.days)
+    assert_equal 0, Profitable.churned_mrr(in_the_last: 30.days)
+  end
+
+  def test_average_revenue_per_customer_zero_when_no_paying_customers
+    assert_equal 0, Profitable.average_revenue_per_customer
+  end
+
+  def test_lifetime_value_zero_when_no_customers_or_zero_churn
+    # no customers
+    assert_equal 0, Profitable.lifetime_value
+
+    # add customers but zero churn
+    Timecop.freeze(Time.now - 35.days) do
+      create_subscription
+    end
+    # churn rate computed as zero
+    Profitable.stub(:churn, Profitable::NumericResult.new(0, :percentage)) do
+      assert_equal 0, Profitable.lifetime_value
+    end
+  end
+
+  def test_normalize_to_monthly_handles_nil_and_case_insensitive_intervals
+    base = Profitable::Processors::Base.new(nil)
+    assert_equal 0, base.send(:normalize_to_monthly, nil, "month", 1)
+    assert_equal 0, base.send(:normalize_to_monthly, 1000, nil, 1)
+    assert_equal 0, base.send(:normalize_to_monthly, 1000, "month", nil)
+
+    assert_in_delta 1000.0, base.send(:normalize_to_monthly, 1000, "Month", 1), 0.001
+    assert_in_delta 41.6667, base.send(:normalize_to_monthly, 1000, "year", 2), 0.001
+    assert_in_delta 30_000.0, base.send(:normalize_to_monthly, 1000, "day", 1), 0.001
+    assert_in_delta 4_000.0, base.send(:normalize_to_monthly, 1000, "week", 1), 0.001
+  end
+
+  def test_negative_amounts_are_clamped_to_zero_in_mrr
+    data = {
+      "subscription_items" => [
+        { "price" => { "unit_amount" => -500, "recurring" => { "interval" => "month", "interval_count" => 1 } } }
+      ]
+    }
+    sub = Pay::Subscription.create!(
+      customer: @customer,
+      processor: "stripe",
+      status: "active",
+      quantity: 1,
+      current_period_start: Time.now - 15.days,
+      current_period_end: Time.now + 15.days,
+      data: data
+    )
+    assert_equal 0, Profitable::MrrCalculator.process_subscription(sub)
+  end
+end