Return Error object on server error response

lib/Adaptor.js

@@ -208,11 +208,14 @@ function get(path, _ref2) {
   var query = _ref2.query;
   var callback = _ref2.callback;
 
-  function isError(_ref3) {
+  function assembleError(_ref3) {
     var response = _ref3.response;
     var error = _ref3.error;
 
-    return [200, 201, 202].indexOf(response.statusCode) == -1 || !!error;
+    if ([200, 201, 202].indexOf(response.statusCode) > -1) return false;
+    if (error) return error;
+
+    return new Error('Server responded with ' + response.statusCode);
   }
 
   return function (state) {
@@ -243,7 +246,8 @@ function get(path, _ref2) {
           'sendImmediately': sendImmediately
         }
       }, function (error, response, body) {
-        if (isError({ error: error, response: response })) {
+        error = assembleError({ error: error, response: response });
+        if (error) {
           reject(error);
         } else {
           resolve(JSON.parse(body));

package.json

@@ -1,6 +1,6 @@
 {
   "name": "language-http",
-  "version": "0.0.8",
+  "version": "0.0.9",
   "description": "An HTTP Language Pack for OpenFn",
   "main": "lib/index.js",
   "scripts": {

src/Adaptor.js

@@ -115,8 +115,11 @@ export function post(url, {body, callback}) {
  * @returns {Operation}
  */
 export function get(path, {query, callback}) {
-  function isError({ response, error }) {
-    return ([200,201,202].indexOf(response.statusCode) == -1 || !!error) 
+  function assembleError({ response, error }) {
+    if ([200,201,202].indexOf(response.statusCode) > -1) return false;
+    if (error) return error;
+
+    return new Error(`Server responded with ${response.statusCode}`)
   }
 
   return state => {
@@ -140,7 +143,8 @@ export function get(path, {query, callback}) {
           'sendImmediately': sendImmediately
         }
       }, function(error, response, body){
-        if ( isError({error, response}) ) {
+        error = assembleError({error, response})
+        if (error) {
           reject(error);
         } else {
           resolve(JSON.parse(body))