Improving error handling (#324)

.jshintrc

@@ -1,4 +1,5 @@
 {
+  "esversion": 9,
   "node": true,
   "globals": {"describe" : true, "it" : true}
 }

lib/geocoder/heregeocoder.js

@@ -1,4 +1,5 @@
 const AbstractGeocoder = require('./abstractgeocoder');
+const ValueError = require('./../error/valueerror');
 
 const OPTIONS = [
   'apiKey',
@@ -71,6 +72,9 @@ class HereGeocoder extends AbstractGeocoder {
       if (err) {
         return callback(err, results);
       } else {
+        if (result.type === 'ApplicationError') {
+          return callback(new ValueError(result.Details), results);
+        }
         var view = result.Response.View[0];
         if (!view) {
           return callback(false, results);

lib/httpadapter/fetchadapter.js

@@ -39,11 +39,19 @@ class FetchAdapter {
           url + '?' + querystring.encode(params),
           options
         );
-
+        const contentType = res.headers.get('content-type');
+        if (!contentType || contentType.indexOf('application/json') === -1) {
+          throw new HttpError(await res.text(), {
+            code: res.statusCode
+          });
+        }
         return res.json();
       })
       .catch(function(error) {
-        var _error = error.cause ? error.cause : error;
+        if (error instanceof HttpError) {
+          throw error;
+        }
+        const _error = error.cause ? error.cause : error;
         throw new HttpError(_error.message, {
           code: _error.code
         });