Merge pull request #77 from com-pas/rename-commons-ns

Added better Error Handling

Author: Rob Tjalma

src/compas-services/foundation.ts

@@ -7,24 +7,53 @@ export const NOT_FOUND_ERROR = 'NotFoundError';
 export const APPLICATION_ERROR = 'ApplicationError';
 export const SERVER_ERROR = 'ServerError';
 
+export const COMMONS_NAMESPACE = 'https://www.lfenergy.org/compas/commons/v1';
+
 export function getOpenScdElement(): OpenSCD {
   return <OpenSCD>document.querySelector('open-scd');
 }
 
-export function handleResponse(response: Response): Promise<string> {
+export async function handleResponse(response: Response): Promise<string> {
   if (!response.ok) {
     let type = APPLICATION_ERROR;
     if (response.status === 404) {
       type = NOT_FOUND_ERROR;
-    } else if (response.status >= 500)
-    {
+    } else if (response.status >= 500) {
       type = SERVER_ERROR;
     }
-    return Promise.reject({type: type, status: response.status, message: response.statusText});
+    return Promise.reject({type: type, status: response.status, message: await processErrorMessage(response)});
   }
   return Promise.resolve(response.text());
 }
 
+export async function processErrorMessage(response: Response): Promise<string> {
+  // default we will return the status text from the response.
+  let errorMessage = response.statusText;
+
+  const body = await response.text();
+  const doc = await parseXml(body);
+  const messages = Array.from(doc.querySelectorAll('ErrorResponse > ErrorMessage') ?? []);
+  // But if there are messages found in the body, we will process these and replace the status text with that.
+  if (messages.length > 0) {
+    errorMessage = '';
+    messages.forEach((errorMessageElement, index) => {
+      const code = errorMessageElement.getElementsByTagNameNS(COMMONS_NAMESPACE, "Code")!.item(0)!.textContent;
+      const message = errorMessageElement.getElementsByTagNameNS(COMMONS_NAMESPACE, "Message")!.item(0)!.textContent;
+
+      if (index > 0) {
+        errorMessage += ', ';
+      }
+
+      errorMessage += message;
+      if (code) {
+        errorMessage += ' (' + code + ')';
+      }
+    })
+  }
+
+  return errorMessage;
+}
+
 export function parseXml(textContent: string): Promise<Document> {
   return Promise.resolve(new DOMParser().parseFromString(textContent, 'application/xml'));
 }

test/unit/compas-services/foundation.test.ts

@@ -0,0 +1,31 @@
+import {expect} from "@open-wc/testing";
+
+import {processErrorMessage} from "../../../src/compas-services/foundation.js";
+
+const errorBody =
+`<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+ <compas-commons:ErrorResponse xmlns:compas-commons="https://www.lfenergy.org/compas/commons/v1">
+   <compas-commons:ErrorMessage>
+     <compas-commons:Code>CORE-8000</compas-commons:Code>
+     <compas-commons:Message>Name is not a correct name to be used later as filename.</compas-commons:Message>
+     <compas-commons:Property>create.request.name</compas-commons:Property>
+   </compas-commons:ErrorMessage>
+ </compas-commons:ErrorResponse>`;
+
+describe('compas-services-foundation', () => {
+  it('when there is no body in the response, the status text will be returned', async () => {
+    const statusText = 'some status text';
+    const response = new Response(null, <ResponseInit>{statusText: statusText});
+    const result = await processErrorMessage(response);
+    expect(result).to.be.equal(statusText);
+  })
+
+  it('when there is a body in the response, the message is retrieved from the body', async () => {
+    const expectedMessage = 'Name is not a correct name to be used later as filename. (CORE-8000)'
+    const statusText = 'some status text';
+    const response = new Response(errorBody, <ResponseInit>{statusText: statusText});
+    const result = await processErrorMessage(response);
+    expect(result).to.be.equal(expectedMessage);
+  })
+});
+