Load exceptions in user resolvers are not reported

[patrick-steele-idem]

If there is an exception when loading a user resolver then the exception is not reported. For example, if there is a syntax error in a user resolver or if the user has a bad import then the exception is swallowed.

This problem is because of the try...catch around the require() calls: https://github.com/benmosher/eslint-plugin-import/blob/master/utils/resolve.js#L140-L155

It is much safer to use code that checks for the existence of a module using require.resolve():

function tryRequire(target) {
  let resolved;
  try {
    // Check if the target exists
    resolved = require.resolve(target);
  } catch(e) {
    // If the target does not exist then just return undefined
    return undefined;
  }

  // If the target exists then return the loaded module
  return require(resolved);
}

I will be submitting a PR.

[ljharb]

Fixed in #1024