fix: adds specific error classes like parse error for handling them

closes #27

source/cli-stock.js

@@ -6,6 +6,7 @@ const storesData = require('./lib/stores');
 
 let pkg = require('./../package.json');
 let IOWS2 = require('./lib/iows2.js');
+const errors = require('./lib/iows2Errors');
 
 function optionalSplitOptionCSV(val) {
   const seperator = ',';
@@ -118,6 +119,9 @@ Examples:
       return iows.getStoreProductAvailability(store.buCode, productId)
         // softly continue the promise chain when there’s just a 404 (not found)
         .catch(err => {
+          if (err instanceof errors.IOWS2ParseError) {
+            return { stock: 0, probability: 'PARSE_ERROR', createdAt: new Date() };
+          }
           // when product could not be found return an empty availability
           if (err.response && err.response.status === 404 && promises.length > 1) {
             return { stock: 0, probability: 'NOT_FOUND', createdAt: new Date() };

source/index.js

@@ -4,6 +4,7 @@ const assert = require('assert');
 
 const IOWS2 = require('./lib/iows2');
 const stores = require('./lib/stores');
+const errors = require('./lib/iows2Errors');
 
 module.exports = {
   /**
@@ -27,4 +28,5 @@ module.exports = {
     return iows.getStoreProductAvailability(buCode, productId)
   },
   stores,
+  errors,
 };

source/lib/iows2.js

@@ -40,6 +40,8 @@ const stores = require('./stores');
  *   Estimated date when the item gets restocked. Can be empty
  */
 
+const errors = require('./iows2Errors');
+
 /**
  * @class IOWS2
  */
@@ -84,7 +86,7 @@ class IOWS2 {
       .then(response => {
         debug('RECEIVED', response.status);
         if (!response.ok) {
-          const err = new Error(`Unexpected http status code ${response.status}`);
+          const err = new errors.IOWS2ResponseError(`Unexpected http status code ${response.status}`);
           // add context variables to error object for provide more information
           err.request = { url, params: params };
           err.response = response;
@@ -113,7 +115,7 @@ class IOWS2 {
     // RestockDateTime may contain an estimated date when the product gets
     // restocked. It also can be missing in the response
     let restockDate = null;
-    if (availability.RetailItemAvailability.RestockDateTime) {
+    if (availability.RetailItemAvailability && availability.RetailItemAvailability.RestockDateTime) {
       restockDate = new Date(availability.RetailItemAvailability.RestockDateTime.$);
     }
 
@@ -179,10 +181,18 @@ class IOWS2 {
         throw err;
       })
       .then(data => {
-        data = IOWS2.parseAvailabilityFromResponseData(data);
-        data.buCode = buCode;
-        data.productId = productId;
-        return data;
+        let parsed = {
+          buCode,
+          productId,
+        };
+        try {
+          parsed = Object.assign(parsed, IOWS2.parseAvailabilityFromResponseData(data));
+        } catch (err) {
+          let error = new errors.IOWS2ParseError('Unable to parse valid looking response: ' + err.message);
+          error.data = data;
+          throw error;
+        }
+        return parsed;
       });
   }
 }

source/lib/iows2Errors.js

@@ -0,0 +1,11 @@
+'use strict';
+
+class IOWS2Error {}
+class IOWS2ParseError extends IOWS2Error{}
+class IOWS2ResponseError extends IOWS2Error{}
+
+module.exports = {
+  IOWS2Error,
+  IOWS2ParseError,
+  IOWS2ResponseError,
+}