From dd51ed2e74b0a3e586c4451c08cc7f430155628e Mon Sep 17 00:00:00 2001
From: Theodore Kruczek <theodore.kruczek@gmail.com>
Date: Sat, 13 Jan 2024 01:12:02 -0500
Subject: [PATCH] fix: :bug: fix time object being mutated

---
 src/body/Moon.ts                              | 23 +++++++++----------
 .../__snapshots__/sun-moon.test.ts.snap       |  6 ++---
 test/sun-moon/sun-moon.test.ts                | 10 ++++++--
 test/transforms/transforms.test.ts            |  3 ---
 4 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/body/Moon.ts b/src/body/Moon.ts
index d0e1b9c..a481845 100644
--- a/src/body/Moon.ts
+++ b/src/body/Moon.ts
@@ -310,17 +310,20 @@ export class Moon {
    * calculations for moon rise/set times are based on http://www.stargazing.net/kepler/moonrise.html article
    */
   static getMoonTimes(date: Date, lat: Degrees, lon: Degrees, isUtc = false) {
+    // Clone the date so we don't change the original
+    const date_ = new Date(date);
+
     if (isUtc) {
-      date.setUTCHours(0, 0, 0, 0);
+      date_.setUTCHours(0, 0, 0, 0);
     } else {
-      date.setHours(0, 0, 0, 0);
+      date_.setHours(0, 0, 0, 0);
     }
 
-    const { rise, set, ye } = Moon.calculateRiseSetTimes_(date, lat, lon);
+    const { rise, set, ye } = Moon.calculateRiseSetTimes_(date_, lat, lon);
 
     const result = {
-      rise: NaN as Date | number,
-      set: NaN as Date | number,
+      rise: null as Date | null,
+      set: null as Date | null,
       ye: null as number | null,
       alwaysUp: null as boolean | null,
       alwaysDown: null as boolean | null,
@@ -328,15 +331,11 @@ export class Moon {
     };
 
     if (rise) {
-      result.rise = new Date(Moon.hoursLater_(date, rise));
-    } else {
-      result.rise = NaN;
+      result.rise = new Date(Moon.hoursLater_(date_, rise));
     }
 
     if (set) {
-      result.set = new Date(Moon.hoursLater_(date, set));
-    } else {
-      result.set = NaN;
+      result.set = new Date(Moon.hoursLater_(date_, set));
     }
 
     if (!rise && !set) {
@@ -350,7 +349,7 @@ export class Moon {
     } else if (rise && set) {
       result.alwaysUp = false;
       result.alwaysDown = false;
-      result.highest = new Date(Moon.hoursLater_(date, Math.min(rise, set) + Math.abs(set - rise) / 2));
+      result.highest = new Date(Moon.hoursLater_(date_, Math.min(rise, set) + Math.abs(set - rise) / 2));
     } else {
       result.alwaysUp = false;
       result.alwaysDown = false;
diff --git a/test/sun-moon/__snapshots__/sun-moon.test.ts.snap b/test/sun-moon/__snapshots__/sun-moon.test.ts.snap
index 54fec88..7b5b54b 100644
--- a/test/sun-moon/__snapshots__/sun-moon.test.ts.snap
+++ b/test/sun-moon/__snapshots__/sun-moon.test.ts.snap
@@ -41,8 +41,8 @@ Object {
 
 exports[`Sun and Moon getMoonIllumination returns fraction and angle of moons illuminated limb and phase 1`] = `
 Object {
-  "angle": 1.870981046981252,
-  "fraction": 0.09702945670419616,
+  "angle": 2.0187380462851525,
+  "fraction": 0.04918501150967336,
   "next": Object {
     "date": "2022-08-27T06:46:57.840Z",
     "firstQuarter": Object {
@@ -74,6 +74,6 @@ Object {
     "to": 0.966136806691289,
     "weight": 6.3825,
   },
-  "phaseValue": 0.8991701089962825,
+  "phaseValue": 0.9288143180691704,
 }
 `;
diff --git a/test/sun-moon/sun-moon.test.ts b/test/sun-moon/sun-moon.test.ts
index f55315e..9579354 100644
--- a/test/sun-moon/sun-moon.test.ts
+++ b/test/sun-moon/sun-moon.test.ts
@@ -31,9 +31,15 @@ describe('Sun and Moon', () => {
   test('Moon Unit Tests', () => {
     expect(Moon.getMoonIllumination(dateObj)).toMatchSnapshot();
 
+    // eslint-disable-next-line no-console
+    console.log('dateObj', dateObj);
+
     Moon.rae(dateObj, 0 as Degrees, 0 as Degrees);
     Moon.getMoonTimes(dateObj, 0 as Degrees, 0 as Degrees, true);
     Moon.getMoonTimes(dateObj, -10 as Degrees, -10 as Degrees, false);
+
+    // eslint-disable-next-line no-console
+    console.log('dateObj', dateObj);
   });
 
   test('getMoonIllumination returns fraction and angle of moons illuminated limb and phase', () => {
@@ -170,8 +176,8 @@ describe('Suncalc.js tests', () => {
   test('getMoonTimes returns moon rise and set times', () => {
     const moonTimes = Moon.getMoonTimes(new Date('2013-03-04UTC'), lat as Degrees, lon as Degrees, true);
 
-    expect(moonTimes.rise.toUTCString()).toEqual('Mon, 04 Mar 2013 23:54:29 GMT');
-    expect(moonTimes.set.toUTCString()).toEqual('Mon, 04 Mar 2013 07:47:58 GMT');
+    expect(moonTimes.rise?.toUTCString()).toEqual('Mon, 04 Mar 2013 23:54:29 GMT');
+    expect(moonTimes.set?.toUTCString()).toEqual('Mon, 04 Mar 2013 07:47:58 GMT');
   });
 });
 
diff --git a/test/transforms/transforms.test.ts b/test/transforms/transforms.test.ts
index fd4b848..89bd2a3 100644
--- a/test/transforms/transforms.test.ts
+++ b/test/transforms/transforms.test.ts
@@ -143,9 +143,6 @@ describe('Rae2Ecf', () => {
     };
     const rae = ecf2rae(lla, ecf);
 
-    // eslint-disable-next-line no-console
-    console.warn(rae);
-
     const ecfCoordinates = rae2ecf(rae, lla);
 
     expect(ecfCoordinates.x).toBeCloseTo(ecf.x);