chore: error controller (wip)

api/server/controllers/errorController.js

@@ -0,0 +1,31 @@
+//handle duplicates
+const handleDuplicateKeyError = (err, res) => {
+  const field = Object.keys(err.keyValue);
+  const code = 409;
+  const error = `An document with that ${field} already exists.`;
+  res.status(code).send({ messages: error, fields: field });
+};
+
+//handle validation errors
+const handleValidationError = (err, res) => {
+  let errors = Object.values(err.errors).map(el => el.message);
+  let fields = Object.values(err.errors).map(el => el.path);
+  let code = 400;
+  if (errors.length > 1) {
+    const formattedErrors = errors.join(' ');
+    res.status(code).send({ messages: formattedErrors, fields: fields });
+  } else {
+    res.status(code).send({ messages: errors, fields: fields });
+  }
+};
+
+// eslint-disable-next-line no-unused-vars
+module.exports = (err, req, res, next) => {
+  try {
+    console.log('congrats you hit the error middleware');
+    if (err.name === 'ValidationError') return (err = handleValidationError(err, res));
+    if (err.code && err.code == 11000) return (err = handleDuplicateKeyError(err, res));
+  } catch (err) {
+    res.status(500).send('An unknown error occurred.');
+  }
+};