test: 🐛 lock timezone for jest testing

jest.config.ts

@@ -10,6 +10,7 @@ const jestConfig = {
   modulePathIgnorePatterns: ['<rootDir>/node_modules/', '<rootDir>/test/sgp4/sgp4prop'],
   coverageReporters: ['lcov', 'html', 'text'],
   coveragePathIgnorePatterns: ['/node_modules/', '/dist/', '/lib/', '/commonjs/', '/test/', '/scripts/', '/coverage/'],
+  globalSetup: '<rootDir>/test/lib/globalSetup.js',
 };
 
 export default jestConfig;

test/body/Moon.test.ts

@@ -150,7 +150,7 @@ describe('Moon', () => {
    * 'rise', 'set', 'ye', 'alwaysUp', 'alwaysDown', and 'highest' properties.
    */
   it('should return with \'rise\', \'set\', \'ye\', \'alwaysUp\', \'alwaysDown\', and \'highest\' properties', () => {
-    const date = exampleDate;
+    const date = new Date(exampleDate.getTime() - exampleDate.getTimezoneOffset() * 60000);
     const lat = 37.7749 as Degrees; // San Francisco latitude
     const lon = -122.4194 as Degrees; // San Francisco longitude
     const isUtc = false;

test/lib/globalSetup.js

@@ -0,0 +1,4 @@
+export default () => {
+  // eslint-disable-next-line no-process-env
+  process.env.TZ = 'EST';
+};

test/lib/globalSetup.test.ts

@@ -0,0 +1,6 @@
+describe('Timezones', () => {
+  it('should always be EST', () => {
+    // This is so that we can check local and utc calculations
+    expect(new Date().getTimezoneOffset()).toBe(300);
+  });
+});