refactor: safely parse errors from Azure DevOps API

lib/modules/platform/azure/azure-helper.ts

@@ -7,6 +7,7 @@ import { logger } from '../../../logger';
 import { streamToString } from '../../../util/streams';
 import { getNewBranchName } from '../util';
 import * as azureApi from './azure-got-wrapper';
+import { WrappedExceptionSchema } from './schema';
 import {
   getBranchNameWithoutRefsPrefix,
   getBranchNameWithoutRefsheadsPrefix,
@@ -82,18 +83,23 @@ export async function getFile(
   if (item?.readable) {
     const fileContent = await streamToString(item);
     try {
-      const jTmp = JSON.parse(fileContent);
-      if (jTmp.typeKey === 'GitItemNotFoundException') {
-        // file not found
-        return null;
-      }
-      if (jTmp.typeKey === 'GitUnresolvableToCommitException') {
-        // branch not found
-        return null;
+      const result = await WrappedExceptionSchema.safeParseAsync(
+        JSON.parse(fileContent)
+      );
+      if (result.success) {
+        if (result.data.typeKey === 'GitItemNotFoundException') {
+          logger.warn(`Unable to find file ${filePath}`);
+          return null;
+        }
+        if (result.data.typeKey === 'GitUnresolvableToCommitException') {
+          logger.warn(`Unable to find branch ${branchName}`);
+          return null;
+        }
       }
     } catch (error) {
       // it 's not a JSON, so I send the content directly with the line under
     }
+
     return fileContent;
   }
   return null; // no file found

lib/modules/platform/azure/schema.ts

@@ -0,0 +1,17 @@
+import type { WrappedException } from 'azure-devops-node-api/interfaces/common/VSSInterfaces';
+import { z } from 'zod';
+
+export const WrappedExceptionSchema: z.ZodSchema<WrappedException> = z.lazy(
+  () =>
+    z.object({
+      customProperties: z.record(z.any()).optional(),
+      errorCode: z.number().optional(),
+      eventId: z.number().optional(),
+      helpLink: z.string().optional(),
+      innerException: WrappedExceptionSchema.optional(),
+      message: z.string().optional(),
+      stackTrace: z.string().optional(),
+      typeKey: z.string().optional(),
+      typeName: z.string().optional(),
+    })
+);