js fetch error handling code example

Example 1: try catch fetch

fetch("/api/foo")
  .then( response => {
    if (!response.ok) { throw response }
    return response.json()  //we only get here if there is no error
  })
  .then( json => {
    this.props.dispatch(doSomethingWithResult(json)) 
  })
  .catch( err => {
    err.text().then( errorMessage => {
      this.props.dispatch(displayTheError(errorMessage))
    })
  })

Example 2: how to handle fetch errors

function CheckError(response) {
  if (response.status >= 200 && response.status <= 299) {
    return response.json();
  } else {
    throw Error(response.statusText);
  }
}

// Now call the function inside fetch promise resolver
fetch(url)
  .then(CheckError)
  .then((jsonResponse) => {
  }).catch((error) => {
  });

Example 3: how to handle fetch errors

const response = await fetch(url);
if (response.status >= 200 && response.status <= 299) {
  const jsonResponse = await response.json();
  console.log(jsonResponse);
} else {
  // Handle errors
  console.log(response.status, response.statusText);
}

Example 4: fetch error handling js

export async function getStaticProps(context) {
  const res = await fetch(`https://...`)
  const data = await res.json()

  //use this statement for the program not to crush but go back to the home page
  if (!data) {
    return {
      redirect: {
        destination: '/',
        permanent: false,
      },
    }
  }

  return {
    props: {}, // will be passed to the page component as props
  }
}