navigation fixed

CableTests/CableTests.swift

@@ -10,8 +10,41 @@ import Testing
 
 struct CableTests {
 
-    @Test func example() async throws {
-        // Write your test here and use APIs like `#expect(...)` to check expected conditions.
+    @Test func metricWireSizingUsesNearestStandardSize() async throws {
+        let calculator = CableCalculator()
+        calculator.voltage = 12
+        calculator.current = 5
+        calculator.length = 10 // meters
+
+        let crossSection = calculator.recommendedCrossSection(for: .metric)
+        #expect(crossSection == 4.0)
+
+        let voltageDrop = calculator.voltageDrop(for: .metric)
+        #expect(abs(voltageDrop - 0.425) < 0.001)
+
+        let dropPercentage = calculator.voltageDropPercentage(for: .metric)
+        #expect(abs(dropPercentage - 3.5417) < 0.001)
+
+        let powerLoss = calculator.powerLoss(for: .metric)
+        #expect(abs(powerLoss - 2.125) < 0.001)
     }
 
+    @Test func imperialWireSizingMatchesExpectedGauge() async throws {
+        let calculator = CableCalculator()
+        calculator.voltage = 120
+        calculator.current = 15
+        calculator.length = 25 // feet
+
+        let awg = calculator.recommendedCrossSection(for: .imperial)
+        #expect(awg == 18.0)
+
+        let voltageDrop = calculator.voltageDrop(for: .imperial)
+        #expect(abs(voltageDrop - 4.722) < 0.01)
+
+        let dropPercentage = calculator.voltageDropPercentage(for: .imperial)
+        #expect(abs(dropPercentage - 3.935) < 0.01)
+
+        let powerLoss = calculator.powerLoss(for: .imperial)
+        #expect(abs(powerLoss - 70.83) < 0.05)
+    }
 }