refactor: rm nested 'links' dir, raise links into apolloLinks/

src/app/apolloLink/apolloLink.ts

@@ -1,38 +1,41 @@
 import { ApolloLink } from "@apollo/client/link/core";
-import {
-  apiHttpLink,
-  errorLink,
-  getAuthTokenLink,
-  //   loggerLink,
-  retryLink,
-} from "./links";
-
-// TODO add apollo-link-rest and delete httpService & authService
+import { apiHttpLink } from "./link.apiHttp";
+import { errorLink } from "./link.error";
+import { getAuthTokenLink } from "./link.getAuthToken";
+import { retryLink } from "./link.retry";
 
+/**
+ * This is the Apollo Link that is used to make all requests to the server.
+ *
+ * **Link Process Outline:** `(1, 2, 3, 4, 5 => SERVER => 5, 4, 3, 2, 1)`
+ *
+ * **Links:**
+ *
+ *    1. loggerLink
+ *       - Only imported and used in dev mode
+ *       - Logs all requests and responses
+ *
+ *    2. getAuthTokenLink
+ *       - Sets Authorization header (value will be null if !token)
+ *
+ *    3. retryLink
+ *       - Catches and retries _NETWORK_ errors
+ *       - _Does not catch/retry GraphQL errors_
+ *
+ *    4. errorLink
+ *       - Logs network errors _AND_ GraphQL errors
+ *       - Catches and retries _GraphQL_ errors
+ *       - When AuthenticationError is thrown on the server, that comes back as a
+ *         _GraphQL_ error which can not be caught by the `retryLink`, so this link
+ *         handles sending the retry-request to the `/auth/token` endpoint.
+ *
+ *    5. apiHttpLink
+ *       - Sends request to the `/api` endpoint
+ */
 export const apolloLink = ApolloLink.from([
-  //   loggerLink,
+  // if needed, loggerLink goes here
   getAuthTokenLink,
   retryLink,
   errorLink,
   apiHttpLink,
 ]);
-
-/*
-LINK PROCESS (1, 2, 3, 4, 5 => SERVER => 5, 4, 3, 2, 1)
-
-1) loggerLink
-      Gets called every time no matter what.
-2) getAuthTokenLink
-      Sets Authorization header; value will be null if !token.
-3) retryLink
-      CAN ONLY CATCH NETWORK ERRORS, NOT GraphQL ERRORS!
-4) errorLink
-      Logs errors AND MOST IMPORTANTLY, GraphQL Errors can only be caught here!
-      errorLink CAN ALSO RETRY REQUESTS! When AuthenticationError is thrown on
-      the server, that comes back as a GraphQL error that can ONLY be caught here!
-      So it is HERE that we make the switch to retry and go to /auth/token.
-5) authSplitterLink
-      If operationName is Login/Register, go to restLink (/auth endpoint)
-      Else go to apiHttpLink (/api endpoint)
-
-*/