Add distribution power summaries

tests/circuit-power-calculation.test.ts

@@ -1,8 +1,11 @@
 import assert from "node:assert/strict";
 import { describe, it } from "node:test";
 import {
+  applyDistributionBoardSimultaneityFactor,
   calculateCircuitTotalPower,
+  calculateDistributionBoardTotalPower,
   calculateRowTotalPower,
+  calculateSectionTotalPower,
 } from "../src/domain/calculations/circuit-power-calculation.js";
 import {
   resolveCircuitPhaseType,
@@ -19,6 +22,32 @@ describe("circuit power calculation", () => {
     ]);
     assert.equal(total, 4.5);
   });
+
+  it("calculates section and distribution-board totals", () => {
+    const lighting = calculateSectionTotalPower([
+      { circuitTotalPower: 1.5 },
+      { circuitTotalPower: 2.25 },
+    ]);
+    const singlePhase = calculateSectionTotalPower([
+      { circuitTotalPower: 3 },
+    ]);
+    const total = calculateDistributionBoardTotalPower([
+      { sectionTotalPower: lighting },
+      { sectionTotalPower: singlePhase },
+      { sectionTotalPower: 0 },
+    ]);
+
+    assert.equal(lighting, 3.75);
+    assert.equal(total, 6.75);
+    assert.equal(
+      applyDistributionBoardSimultaneityFactor(total, 0.8),
+      5.4
+    );
+    assert.throws(
+      () => applyDistributionBoardSimultaneityFactor(total, 1.1),
+      /between zero and one/
+    );
+  });
 });
 
 describe("project voltage derivation", () => {