feat(growth): add weight-for-height calculation

test/growth/score/weight_for_height_test.exs

@@ -0,0 +1,142 @@
+# test/growth/score/weight_for_height_test.exs
+defmodule Growth.Score.WeightForHeightTest do
+  use ExUnit.Case, async: true
+
+  alias Growth
+  alias Growth.Score.WeightForHeight
+
+  describe "measure_name/0" do
+    test "returns the correct measure name atom" do
+      assert WeightForHeight.measure_name() == :weight_for_height
+    end
+  end
+
+  describe "lms/2" do
+    test "returns LMS values for exact height match" do
+      growth = %Growth{
+        gender: :male,
+        weight: 7.3,
+        height: 65.0,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth, WeightForHeight) == [
+               {"height", {-0.35210000000000002, 7.4326999999999996, 0.082170000000000007}}
+             ]
+    end
+
+    test "returns LMS values for closest height match when exact is not found" do
+      growth = %Growth{
+        gender: :male,
+        weight: 7.3,
+        height: 64.9,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth, WeightForHeight) == [
+               {"height", {-0.35210000000000002, 7.4326999999999996, 0.082170000000000007}}
+             ]
+
+      growth_closer_to_higher = %Growth{
+        gender: :male,
+        weight: 7.4,
+        height: 65.09,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth_closer_to_higher, WeightForHeight) == [
+               {"height", {-0.35210000000000002, 7.4562999999999997, 0.082159999999999997}}
+             ]
+    end
+
+    test "returns empty list if weight or height is missing" do
+      growth_no_weight = %Growth{
+        gender: :male,
+        height: 60.0,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth_no_weight, WeightForHeight) == []
+
+      growth_no_height = %Growth{
+        gender: :male,
+        weight: 5.0,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth_no_height, WeightForHeight) == []
+
+      growth_nil_values = %Growth{
+        gender: :male,
+        weight: nil,
+        height: nil,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth_nil_values, WeightForHeight) == []
+    end
+
+    test "returns empty list if no matching gender data exists" do
+      # Assuming no :unknown gender data was inserted
+      growth = %Growth{
+        gender: :unknown,
+        weight: 5.0,
+        height: 60.0,
+        name: "Joe Doe",
+        date_of_measurement: Date.utc_today(),
+        date_of_birth: Date.shift(Date.utc_today(), day: -91)
+      }
+
+      assert WeightForHeight.lms(growth, WeightForHeight) == []
+    end
+  end
+
+  describe "find_closest_height/2" do
+    test "finds the lower closest height" do
+      assert WeightForHeight.find_closest_height(:male, 64.99) == [
+               {"height", {-0.35210000000000002, 7.4326999999999996, 0.082170000000000007}}
+             ]
+    end
+
+    test "finds the higher closest height" do
+      assert WeightForHeight.find_closest_height(:male, 65.61) == [
+               {"height", {-0.35210000000000002, 7.5738000000000003, 0.082140000000000005}}
+             ]
+    end
+
+    test "finds the lower closest height when exactly midway" do
+      expected_lms =
+        [
+          [{"height", {-0.35210000000000002, 7.5034000000000001, 0.082150000000000001}}],
+          [{"height", {-0.35210000000000002, 7.4798999999999998, 0.082159999999999997}}]
+        ]
+
+      lms = WeightForHeight.find_closest_height(:male, 65.25)
+      assert Enum.any?(expected_lms, fn entity_lms -> entity_lms == lms end)
+    end
+
+    test "do not match when below minimum height" do
+      assert WeightForHeight.find_closest_height(:male, 44.0) == []
+    end
+
+    test "do not match when above maximum height" do
+      assert WeightForHeight.find_closest_height(:male, 121.0) == []
+    end
+
+    test "returns empty list when no data exists for the gender" do
+      assert WeightForHeight.find_closest_height(:unknown, 60.0) == []
+    end
+  end
+end

test/support/growth_data.ex

@@ -61,6 +61,14 @@ defmodule Growth.Data do
   weight-for-age,male,day,28,0.2331,4.3670999999999998,0.13497000000000001,2.8540000000000001,3.3050000000000002,3.8069999999999999,4.367,4.9880000000000004,5.6740000000000004,6.43
   weight-for-age,male,week,4,0.2331,4.3670999999999998,0.13497000000000001,2.9,3.3,3.8,4.4000000000000004,5,5.7,6.4
   weight-for-age,male,month,1,0.22969999999999999,4.4709000000000003,0.13395000000000001,2.9,3.4,3.9,4.5,5.0999999999999996,5.8,6.6
+  weight-for-height,female,length,65,-0.38329999999999997,7.0811999999999999,0.091189999999999993,5.4589999999999996,5.9370000000000003,6.4740000000000002,7.0810000000000004,7.77,8.5549999999999997,9.4540000000000006
+  weight-for-height,female,length,65.099999999999994,-0.38329999999999997,7.1040999999999999,0.091179999999999997,5.4770000000000003,5.9560000000000004,6.4950000000000001,7.1040000000000001,7.7949999999999999,8.5820000000000007,9.484
+  weight-for-height,female,height,65,-0.38329999999999997,7.2401999999999997,0.091130000000000003,5.5830000000000002,6.0709999999999997,6.62,7.24,7.944,8.7460000000000004,9.6639999999999997
+  weight-for-height,female,height,65.099999999999994,-0.38329999999999997,7.2626999999999997,0.091120000000000007,5.6,6.09,6.64,7.2629999999999999,7.9690000000000003,8.7729999999999997,9.6940000000000008
+  weight-for-height,male,length,65,-0.35210000000000002,7.2666000000000004,0.082229999999999998,5.7359999999999998,6.1929999999999996,6.7009999999999996,7.2670000000000003,7.899,8.6080000000000005,9.4060000000000006
+  weight-for-height,male,length,65.099999999999994,-0.35210000000000002,7.2904999999999998,0.082220000000000001,5.7549999999999999,6.2130000000000001,6.7229999999999999,7.29,7.9249999999999998,8.6359999999999992,9.4369999999999994
+  weight-for-height,male,height,65,-0.35210000000000002,7.4326999999999996,0.082170000000000007,5.8680000000000003,6.335,6.8540000000000001,7.4329999999999998,8.0790000000000006,8.8040000000000003,9.6189999999999998
+  weight-for-height,male,height,65.099999999999994,-0.35210000000000002,7.4562999999999997,0.082159999999999997,5.8869999999999996,6.3550000000000004,6.8760000000000003,7.4560000000000004,8.1050000000000004,8.8309999999999995,9.6489999999999991
   """
 
   @doc """