Add the ability to "rollup" values in a time series (#554)

* Clean up time series models

* Add value group rollup class for summarizing hierarchical data

* Integrate new classes

* Update UI to use new patterns

* Update D3 charts to expect new data format

* Clean up account model

* More cleanup

* Money improvements

* Use new money fields

* Remove invalid fixture data to avoid orphaned accountables

* Update time series to work better with collections

* Fix tests and UI bugs

test/models/time_series_test.rb

@@ -0,0 +1,75 @@
+require "test_helper"
+
+class TimeSeriesTest < ActiveSupport::TestCase
+  test "it can accept array of money values" do
+    series = TimeSeries.new([ { date: 1.day.ago.to_date, value: Money.new(100) }, { date: Date.current, value: Money.new(200) } ])
+
+    assert_equal Money.new(100), series.first.value
+    assert_equal Money.new(200), series.last.value
+    assert_equal :normal, series.type
+    assert_equal "up", series.trend.direction
+    assert_equal Money.new(100), series.trend.value
+    assert_equal 100.0, series.trend.percent
+  end
+
+  test "it can accept array of numeric values" do
+    series = TimeSeries.new([ { date: 1.day.ago.to_date, value: 100 }, { date: Date.current, value: 200 } ])
+
+    assert_equal 100, series.first.value
+    assert_equal 200, series.last.value
+    assert_equal 100, series.on(1.day.ago.to_date).value
+    assert_equal :normal, series.type
+    assert_equal "up", series.trend.direction
+    assert_equal 100, series.trend.value
+    assert_equal 100.0, series.trend.percent
+  end
+
+  test "when nil or empty array passed, it returns empty series" do
+    series = TimeSeries.new(nil)
+    assert_equal [], series.values
+
+    series = TimeSeries.new([])
+
+    assert_nil series.first
+    assert_nil series.last
+    assert_equal({ values: [], trend: { type: "normal", direction: "flat", value: 0, percent: 0.0 }, type: "normal" }.to_json, series.to_json)
+  end
+
+  test "money series can be serialized to json" do
+    expected_values = {
+      values: [
+        {
+          date: "2024-03-17",
+          value: { amount: "100.0", currency: "USD" },
+          trend: { type: "normal", direction: "flat", value: { amount: "0.0", currency: "USD" }, percent: 0.0 }
+        },
+        {
+          date: "2024-03-18",
+          value: { amount: "200.0", currency: "USD" },
+          trend: { type: "normal", direction: "up", value: { amount: "100.0", currency: "USD" }, percent: 100.0 }
+        }
+      ],
+      trend: { type: "normal", direction: "up", value: { amount: "100.0", currency: "USD" }, percent: 100.0 },
+      type: "normal"
+    }.to_json
+
+    series = TimeSeries.new([ { date: 1.day.ago.to_date, value: Money.new(100) }, { date: Date.current, value: Money.new(200) } ])
+
+    assert_equal expected_values, series.to_json
+  end
+
+  test "numeric series can be serialized to json" do
+    expected_values = {
+        values: [
+            { date: 1.day.ago.to_date, value: 100, trend: { type: "normal", direction: "flat", value: 0, percent: 0.0 } },
+            { date: Date.current, value: 200, trend: { type: "normal", direction: "up", value: 100, percent: 100.0 } }
+        ],
+        trend: { type: "normal", direction: "up", value: 100, percent: 100.0 },
+        type: "normal"
+    }.to_json
+
+    series = TimeSeries.new([ { date: 1.day.ago.to_date, value: 100 }, { date: Date.current, value: 200 } ])
+
+    assert_equal expected_values, series.to_json
+  end
+end