Switch the base framework from Create React App to Next.JS

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

src/utils/cypress-attribute.ts

@@ -41,7 +41,10 @@ export const cypressId = (
  * @param value The attribute content
  * @return An object if in test mode, undefined otherwise.
  */
-export const cypressAttribute = (attribute: string, value: string): Record<string, string> | undefined => {
+export const cypressAttribute = (
+  attribute: string,
+  value: string | undefined
+): Record<string, string | undefined> | undefined => {
   if (!isTestMode()) {
     return
   }

src/utils/is-client-side-rendering.ts

@@ -0,0 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export const isClientSideRendering = (): boolean => {
+  return typeof window !== 'undefined' && typeof window.navigator !== 'undefined'
+}

src/utils/test-modes.ts

@@ -4,18 +4,22 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+/**
+ * Checks if the current runtime is built in e2e test mode.
+ */
 export const isTestMode = (): boolean => {
-  return !!process.env.REACT_APP_TEST_MODE
+  return process.env.NEXT_PUBLIC_TEST_MODE === 'true'
 }
 
+/**
+ * Checks if the current runtime should use the mocked backend.
+ */
 export const isMockMode = (): boolean => {
-  return process.env.REACT_APP_BACKEND_BASE_URL === undefined
+  return process.env.NEXT_PUBLIC_USE_MOCK_API === 'true'
 }
 
 /**
  * Checks if the current runtime was built in development mode.
- *
- * @return {@code true} if the runtime was built in development mode.
  */
 export const isDevMode = (): boolean => {
   return process.env.NODE_ENV === 'development'