Add a Delete Note API

Finally, we are going to create an API that allows a user to delete a given note.

Add the Function

Create a new file delete.js and paste the following code

import handler from "./libs/handler-lib";
import dynamoDb from "./libs/dynamodb-lib";

export const main = handler(async (event, context) => {
  const params = {
    TableName: process.env.tableName,
    // 'Key' defines the partition key and sort key of the item to be removed
    Key: {
      userId: "123", // The id of the author
      noteId: event.pathParameters.id, // The id of the note from the path
    },
  };

  await dynamoDb.delete(params);

  return { status: true };
});

This makes a DynamoDB delete call with the userId & noteId key to delete the note.

Configure the API Endpoint

Open the serverless.yml file and append the following to it.

  delete:
    # Defines an HTTP API endpoint that calls the main function in delete.js
    # - path: url path is /notes/{id}
    # - method: DELETE request
    handler: delete.main
    events:
      - http:
          path: notes/{id}
          cors: true
          method: delete

This adds a DELETE request handler to the /notes/{id} endpoint.

Test

Create a mocks/delete-event.json file and add the following.

Just like before we’ll use the noteId of our note in place of the id in the pathParameters block.

{
  "pathParameters": {
    "id": "578eb840-f70f-11e6-9d1a-1359b3b22944"
  }
}

Invoke our newly created function from the root directory.

$ serverless invoke local --function delete --path mocks/delete-event.json

And the response should look similar to this.

{
    "statusCode": 200,
    "body": "{\"status\":true}"
}

Now that our APIs are complete, let’s deploy them next!