The data folder contains a database populated with test posts.

Database access will be done using the db.js file included inside the data folder.

The db.js publishes the following methods.

• find(): calling find returns a promise that resolves to an array of all the posts contained in the database.
• findById(): this method expects an id as it's only parameter and returns a promise that resolves to the post corresponding to the id provided or an empty array if no post with that id is found.
• insert(): calling insert passing it a post object will add it to the database and return a promise that resolves to an object with the id of the inserted post. The object looks like this: { id: 123 }.
• update(): accepts two arguments, the first is the id of the post to update and the second is an object with the changes to apply. It returns a promise that resolves to the count of updated records. If the count is 1 it means the record was updated correctly.
• remove(): the remove method accepts an id as its first parameter and upon successfully deleting the post from the database it returns a promise that resolves to the number of records deleted.
• findPostComments(): the findPostComments accepts a postId as its first parameter and returns a promise that resolves to an array of all comments on the post associated with the post id.
• findCommentById(): accepts an id and returns a promise that resolves to the comment associated with that id.
• insertComment(): calling insertComment while passing it a comment object will add it to the database and return a promise that resolves to an object with the id of the inserted comment. The object looks like this: { id: 123 }. This method will throw an error if the post_id field in the comment object does not match a valid post id in the database.

Now that we have a way to add, update, remove and retrieve data from the provided database, it is time to work on the API.

A Blog Post in the database has the following structure:

{
  title: "The post title", // String, required
  contents: "The post contents", // String, required
  created_at: Mon Aug 14 2017 12:50:16 GMT-0700 (PDT) // Date, defaults to current date
  updated_at: Mon Aug 14 2017 12:50:16 GMT-0700 (PDT) // Date, defaults to current date
}

A Comment in the database has the following structure:

{
  text: "The text of the comment", // String, required
  post_id: "The id of the associated post", // Integer, required, must match the id of a post entry in the database
  created_at: Mon Aug 14 2017 12:50:16 GMT-0700 (PDT) // Date, defaults to current date
  updated_at: Mon Aug 14 2017 12:50:16 GMT-0700 (PDT) // Date, defaults to current date
}

• Add the code necessary to implement the endpoints listed below.
• Separate the endpoints that begin with /api/posts into a separate Express Router.

Configure the API to handle to the following routes:

| DELETE | /api/posts/:id | Removes the post with the specified id and returns the deleted post object. You may need to make additional calls to the database in order to satisfy this requirement. | | PUT | /api/posts/:id | Updates the post with the specified id using data from the request body. Returns the modified document, NOT the original. |

When the client makes a POST request to /api/posts:

• If the request body is missing the title or contents property:

• If the information about the post is valid:

• If there's an error while saving the post:

When the client makes a POST request to /api/posts/:id/comments:

• If the post with the specified id is not found:

• If the request body is missing the text property:

• If the information about the comment is valid:

• If there's an error while saving the comment:

When the client makes a GET request to /api/posts:

• If there's an error in retrieving the posts from the database:

When the client makes a GET request to /api/posts/:id:

• If the post with the specified id is not found:

• If there's an error in retrieving the post from the database:

When the client makes a GET request to /api/posts/:id/comments:

• If the post with the specified id is not found:

• If there's an error in retrieving the comments from the database:

When the client makes a DELETE request to /api/posts/:id:

• If the post with the specified id is not found:

  • return HTTP status code 404 (Not Found).
  • return the following JSON object: { message: "The post with the specified ID does not exist." }.

• If there's an error in removing the post from the database:

  • cancel the request.
  • respond with HTTP status code 500.
  • return the following JSON object: { error: "The post could not be removed" }.

When the client makes a PUT request to /api/posts/:id:

• If the post with the specified id is not found:

• If the request body is missing the title or contents property:

• If there's an error when updating the post:

  • cancel the request.
  • respond with HTTP status code 500.
  • return the following JSON object: { error: "The post information could not be modified." }.

• If the post is found and the new information is valid:

  • update the post document in the database using the new information sent in the request body.
  • return HTTP status code 200 (OK).
  • return the newly updated post.

To work on the stretch problems you'll need to enable the cors middleware. Follow these steps:

• add the cors npm module: npm i cors.
• add server.use(cors()) after server.use(express.json()).

Create a new React application and connect it to your server:

• Use create-react-app to create an application inside the root folder, name it client.
• From the React application connect to the /api/posts endpoint in the API and show the list of posts.
• Style the list of posts however you see fit.