Understanding Server & Client Side Code

Assuming we have set up a POST route in the file server.js file, we will move into the website folder and start writing client side code in a file named app.js. Here is the code we could use to make a POST request to our route:

const postData = async ( url = '', data = {})=>{
    console.log(data);
      const response = await fetch(url, {
      method: 'POST', 
      credentials: 'same-origin',
      headers: {
          'Content-Type': 'application/json',
      },
     // Body data type must match "Content-Type" header        
      body: JSON.stringify(data), 
    });

      try {
        const newData = await response.json();
        console.log(newData);
        return newData;
      }catch(error) {
      console.log("error", error);
      }
  }

postData('/add', {answer:42});

On the next page is a screencast showing this in action.