Add basic version of Comments component

app/javascript/actions/requestComments.ts

@@ -0,0 +1,63 @@
+import { Action } from 'redux';
+import { ThunkAction } from 'redux-thunk';
+
+import ICommentJSON from '../interfaces/json/IComment';
+
+import { State } from '../reducers/rootReducer';
+
+export const COMMENTS_REQUEST_START = 'COMMENTS_REQUEST_START';
+interface CommentsRequestStartAction {
+  type: typeof COMMENTS_REQUEST_START;
+}
+
+export const COMMENTS_REQUEST_SUCCESS = 'COMMENTS_REQUEST_SUCCESS';
+interface CommentsRequestSuccessAction {
+  type: typeof COMMENTS_REQUEST_SUCCESS;
+  comments: Array<ICommentJSON>;
+  page: number;
+}
+
+export const COMMENTS_REQUEST_FAILURE = 'COMMENTS_REQUEST_FAILURE';
+interface CommentsRequestFailureAction {
+  type: typeof COMMENTS_REQUEST_FAILURE;
+  error: string;
+}
+
+export type CommentsRequestActionTypes =
+  CommentsRequestStartAction |
+  CommentsRequestSuccessAction |
+  CommentsRequestFailureAction;
+
+
+const commentsRequestStart = (): CommentsRequestActionTypes => ({
+  type: COMMENTS_REQUEST_START,
+});
+
+const commentsRequestSuccess = (
+  comments: Array<ICommentJSON>,
+  page: number
+): CommentsRequestActionTypes => ({
+  type: COMMENTS_REQUEST_SUCCESS,
+  comments,
+  page,
+});
+
+const commentsRequestFailure = (error: string): CommentsRequestActionTypes => ({
+  type: COMMENTS_REQUEST_FAILURE,
+  error,
+});
+
+export const requestComments = (
+  postId: number,
+  page: number,
+): ThunkAction<void, State, null, Action<string>> => async (dispatch) => {
+  dispatch(commentsRequestStart());
+
+  try {
+    const response = await fetch(`/posts/${postId}/comments?page=${page}`);
+    const json = await response.json();
+    dispatch(commentsRequestSuccess(json, page));
+  } catch (e) {
+    dispatch(commentsRequestFailure(e));
+  }
+}