From 17c5c07ae94300638042b144946d6a69d5caf759 Mon Sep 17 00:00:00 2001
From: Aaron Brethorst <aaron@brethorsting.com>
Date: Thu, 16 Jan 2025 16:40:22 -0800
Subject: [PATCH] Adds unit tests for mathUtils

---
 src/lib/mathUtils.js            |   2 +-
 src/tests/lib/mathUtils.test.js | 101 ++++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 src/tests/lib/mathUtils.test.js

diff --git a/src/lib/mathUtils.js b/src/lib/mathUtils.js
index 6eb5391..26e3592 100644
--- a/src/lib/mathUtils.js
+++ b/src/lib/mathUtils.js
@@ -14,7 +14,7 @@ export function toDirection(orientation) {
 		direction += 360;
 	}
 
-	return direction;
+	return direction === 0 ? 0 : direction;
 }
 
 /**
diff --git a/src/tests/lib/mathUtils.test.js b/src/tests/lib/mathUtils.test.js
new file mode 100644
index 0000000..3dbcace
--- /dev/null
+++ b/src/tests/lib/mathUtils.test.js
@@ -0,0 +1,101 @@
+import { describe, it, expect } from 'vitest';
+import { toDirection, calculateMidpoint } from '$lib/mathUtils';
+
+describe('toDirection', () => {
+    it('converts east orientation (0°) to 90° direction', () => {
+        expect(toDirection(0)).toBe(90);
+    });
+
+    it('converts north orientation (90°) to 0° direction', () => {
+        expect(toDirection(90)).toBe(0);
+    });
+
+    it('converts west orientation (180°) to 270° direction', () => {
+        expect(toDirection(180)).toBe(270);
+    });
+
+    it('converts south orientation (270°) to 180° direction', () => {
+        expect(toDirection(270)).toBe(180);
+    });
+
+    it('handles negative orientations', () => {
+        expect(toDirection(-90)).toBe(180);  // -90° orientation should be 180° direction
+        expect(toDirection(-180)).toBe(270); // -180° orientation should be 270° direction
+        expect(toDirection(-270)).toBe(0);   // -270° orientation should be 0° direction
+    });
+
+    it('handles orientations > 360°', () => {
+        expect(toDirection(450)).toBe(0);    // 450° orientation (90° + 360°) should be 0° direction
+        expect(toDirection(720)).toBe(90);   // 720° orientation (0° + 2*360°) should be 90° direction
+    });
+
+    it('converts arbitrary angles correctly', () => {
+        expect(toDirection(45)).toBe(45);    // 45° orientation to 45° direction
+        expect(toDirection(135)).toBe(315);  // 135° orientation to 315° direction
+        expect(toDirection(225)).toBe(225);  // 225° orientation to 225° direction
+        expect(toDirection(315)).toBe(135);  // 315° orientation to 135° direction
+    });
+});
+
+describe('calculateMidpoint', () => {
+    it('calculates midpoint for two stops', () => {
+        const stops = [
+            { lat: 47.6062, lon: -122.3321 },
+            { lat: 47.6092, lon: -122.3331 }
+        ];
+        
+        const result = calculateMidpoint(stops);
+        
+        expect(result.lat).toBeCloseTo(47.6077);
+        expect(result.lng).toBeCloseTo(-122.3326);
+    });
+
+    it('calculates midpoint for multiple stops', () => {
+        const stops = [
+            { lat: 47.6062, lon: -122.3321 },
+            { lat: 47.6092, lon: -122.3331 },
+            { lat: 47.6082, lon: -122.3341 }
+        ];
+        
+        const result = calculateMidpoint(stops);
+        
+        expect(result.lat).toBeCloseTo(47.6079);
+        expect(result.lng).toBeCloseTo(-122.3331);
+    });
+
+    it('returns same point for single stop', () => {
+        const stops = [
+            { lat: 47.6062, lon: -122.3321 }
+        ];
+        
+        const result = calculateMidpoint(stops);
+        
+        expect(result.lat).toBe(47.6062);
+        expect(result.lng).toBe(-122.3321);
+    });
+
+    it('handles positive and negative coordinates', () => {
+        const stops = [
+            { lat: -33.8688, lon: 151.2093 },  // Sydney
+            { lat: 40.7128, lon: -74.0060 }    // New York
+        ];
+        
+        const result = calculateMidpoint(stops);
+        
+        expect(result.lat).toBeCloseTo(3.422);
+        expect(result.lng).toBeCloseTo(38.6017);
+    });
+
+    it('handles coordinates around the same area', () => {
+        const stops = [
+            { lat: 47.6062, lon: -122.3321 },
+            { lat: 47.6065, lon: -122.3324 },
+            { lat: 47.6068, lon: -122.3327 }
+        ];
+        
+        const result = calculateMidpoint(stops);
+        
+        expect(result.lat).toBeCloseTo(47.6065);
+        expect(result.lng).toBeCloseTo(-122.3324);
+    });
+});
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