window.history cannot be cleared, push "/" URL instead

jest.config.js

@@ -4,8 +4,14 @@
 const config = {
   testEnvironment: 'jsdom',
 
+  // Run once per test file
+  // Executed before executing setupFilesAfterEnv and before the test code itself
   setupFiles: ['./jest.setup.ts'],
 
+  // Run before each test file in the suite is executed
+  // Meant for code which is repeating in each test file
+  setupFilesAfterEnv: ['./jest.setup-after-env.ts'],
+
   // By default Jest allows for __tests__/*.js, *.spec.js and *.test.js
   // https://jestjs.io/docs/en/configuration#testregex-string-array-string
   // Let's be strict and use *.test.js only

jest.setup-after-env.ts

@@ -0,0 +1,19 @@
+console.log('setup-after-env.ts');
+
+beforeEach(() => {
+  // window.history cannot be cleared: https://stackoverflow.com/q/20044554
+  //
+  // So BrowserRouter cannot be cleared between tests:
+  // - https://github.com/testing-library/react-testing-library/issues/518
+  // - https://v5.reactrouter.com/web/guides/testing
+  //   "You can also use BrowserRouter if your test environment has the browser globals window.location and window.history
+  //   (which is the default in Jest through JSDOM, but **you cannot reset the history between tests**)"
+  //
+  // The only solution is to push a new state to the history with "/" URL between tests
+  // so window.location.href is not polluted by previous tests in the same file
+  //
+  // Other solutions:
+  // - Use MemoryRouter instead of BrowserRouter when possible
+  // - Move each test that uses BrowserRouter in its own file
+  window.history.pushState({}, 'unused', '/');
+});