address the comments

Author: yelizhenden-mdb

tools/spectral/ipa/__tests__/eachCustomMethodMustBeGetOrPost.test.js

@@ -18,6 +18,14 @@ testRule('xgen-IPA-109-custom-method-must-be-GET-or-POST', [
         '/b:method': {
           get: {},
         },
+        '/c/{exampleId}:method': {
+          get: {},
+          'x-xgen-IPA-exception': {}
+        },
+        '/c:method': {
+          get: {},
+          'x-xgen-IPA-exception': {}
+        },
       },
     },
     errors: [],

tools/spectral/ipa/rulesets/IPA-109.yaml

@@ -9,6 +9,6 @@ rules:
     description: 'The HTTP method for custom methods must be GET or POST. http://go/ipa/109'
     message: '{{error}} http://go/ipa/109'
     severity: warn
-    given: '$.paths[*]'
+    given: "$.paths[*]"
     then:
       function: 'eachCustomMethodMustBeGetOrPost'

tools/spectral/ipa/rulesets/functions/eachCustomMethodMustBeGetOrPost.js

@@ -3,14 +3,17 @@ import { isCustomMethod } from './utils/resourceEvaluation.js';
 const ERROR_MESSAGE = 'The HTTP method for custom methods must be GET or POST.';
 const ERROR_RESULT = [{ message: ERROR_MESSAGE }];
 const VALID_METHODS = ['get', 'post'];
+const EXCEPTION_EXTENSION_KEY = 'x-xgen-IPA-exception';
 
 export default (input, opts, { path }) => {
   // Extract the path key (e.g., '/a/{exampleId}:method') from the JSONPath.
   let pathKey = path[1];
 
   if (!isCustomMethod(pathKey)) return;
 
-  const httpMethods = Object.keys(input);
+  //Exclude exception extension key
+  let keys = Object.keys(input);
+  const httpMethods = keys.filter(key => key !== EXCEPTION_EXTENSION_KEY);
 
   // Check for invalid methods
   if (httpMethods.some((method) => !VALID_METHODS.includes(method))) {