🧿 Current issues / What's wrong ?

Current fetch request does not support timeout, nor keep alive connections.

💊 Fixes / Solution

Migrate the fetch library from cross-fetch to ofetch.

The error handling changes from ofetch will also introduce a change in returned response on error.

Previously, error handling looks like:

try {
  const body = await getScores(x);
  if (body.error) { // Handle error from score-api };
  return body.result;
} catch(e) {
  // do something with e, which is an Error object, for network error, or JSON parse error
}

With ofetch changes,

try {
  const body = await getScores(x);
  return body.result;
} catch(e) {
  // do something with e, which is an JSON-RPC object
  if (typeof e.code === 'string') {
    // Error from score-api
  } else {
    // Network error 
  }
}

🚧 Changes

• Add support for keep alive connections
• Add timeout to all fetch requests
• All non-200 status code throw an error
• All errors thrown follow the same format as the underlying service error, beside getJSON and ipfsGet (see below)

getScores, validate and getVp

• SUCCESS: The promise will resolve with the score JSON object
• ERROR (from score-api): Promise rejection with JSON-RPC object (code === string)
• ERROR (network): Promise rejection with JSON-RPC object (code === number)

The last argument (options) accepts a timeout property.

subgrapherRequest and getSnapshot

• SUCCESS: return the JSON object
• ERROR (subgrapher): return a JSON graphQL error object
• ERROR (network): return a GraphQL like error object
• ERROR (not json response): return a GraphQL like error object

The last argument (options) accepts a timeout property.

getJSON and ipfsGet

• SUCCESS: return the JSON object
• ERROR (network): throw a FetchError
• ERROR (not json response): throw an JSON parse error

The last argument (options) accepts a timeout property.

send (from Client)

• SUCCESS: return the JSON object
• ERROR (from sequencer): Promise rejection with JSON-RPC object
• ERROR (network): throw FetchError

‼️ Breaking changes

• ofetch is handling error response differently, and is rejecting a Promise on all non-200 errors.

This new update will require a bump to the next major version (1.x.x).
As this new breaking change need more testing before public release, the new 1.x.x should be released as a beta, and used only by our internal services first (and keep updated with the main branch) for a few weeks.

Once everything confirmed as working as expected, then we can public release it.

🛠️ Tests

• Call the getScores, validate, getSnapshot and getVp functions with valid data
• It should return the expected object
• Call them again with invalid data
• It should return a JSON-RPC error object, from score-api
• Call them again with invalid url (pass something else as score-api url)
• It should return JSON-RPC error object