fix(success response handler): parse unsafe integers as strings

package.json

@@ -88,6 +88,7 @@
         }
     },
     "dependencies": {
+        "core-js": "^3.37.1",
         "exponential-backoff": "^3.1.0",
         "query-string-cjs": "npm:query-string@^7.0.0",
         "query-string-esm": "npm:query-string@^9.0.0"

src/handlers/response/ResponseHandlers.ts

@@ -1,3 +1,5 @@
+// TODO CDX-1574: remove this polyfill when we bump the minimal supported Node.js version to 22
+import 'core-js/actual/json/parse.js';
 import {Predicate} from '../../utils/types.js';
 import {ResponseBodyFormat, ResponseHandler} from './ResponseHandlerInterfaces.js';
 
@@ -14,7 +16,23 @@ const noContent: ResponseHandler = {
 
 const success: ResponseHandler = {
     canProcess: isAnyOkStatus,
-    process: async (response, responseBodyFormat = 'json') => response[responseBodyFormat](),
+    process: async (response, responseBodyFormat = 'json') => {
+        if (responseBodyFormat !== 'json') {
+            return response[responseBodyFormat]();
+        }
+        const content = await response.text();
+        return (
+            JSON.parse as (
+                text: string,
+                reviver?: (key: string, value: any, context: {source: any}) => any | undefined,
+            ) => any
+        )(content, (_key, value, context) => {
+            if (typeof value === 'number' && !Number.isSafeInteger(Math.floor(value))) {
+                return context.source;
+            }
+            return value;
+        });
+    },
 };
 
 /**

src/handlers/response/tests/ResponseHandlers.spec.ts

@@ -10,11 +10,41 @@ describe('ResponseHandlers', () => {
     });
 
     describe.each([200, 299])('when the response status code is between 200 and 299 (success)', (status) => {
-        it(`${status} returns a promise resolved with the response body in JSON format`, async () => {
-            const data = {someData: 'thank you!'};
-            const okResponse = new Response(JSON.stringify(data), {status});
-            const result = await handleResponse(okResponse);
-            expect(result).toEqual(data);
+        describe('if responseBodyFormat = "json", or by default', () => {
+            it(`${status} returns a promise resolved with the response body in JSON format`, async () => {
+                const data = {someData: 'thank you!'};
+                const okResponse = new Response(JSON.stringify(data), {status});
+                const result = await handleResponse(okResponse);
+                expect(result).toEqual(data);
+            });
+
+            it(`${status} parses unsafe integer as a string`, async () => {
+                const data = '{"unsafeInteger": 9999999999999999}';
+                const okResponse = new Response(data, {status});
+                const result = await handleResponse(okResponse);
+                expect(result).toEqual({unsafeInteger: '9999999999999999'});
+            });
+
+            it(`${status} parses safe integer as an integer`, async () => {
+                const data = '{"safeInteger": 999999999999999}';
+                const okResponse = new Response(data, {status});
+                const result = await handleResponse(okResponse);
+                expect(result).toEqual({safeInteger: 999999999999999});
+            });
+
+            it(`${status} parses float whose integer part is unsafe as a string`, async () => {
+                const data = '{"float": 9999999999999999.9}';
+                const okResponse = new Response(data, {status});
+                const result = await handleResponse(okResponse);
+                expect(result).toEqual({float: '9999999999999999.9'});
+            });
+
+            it(`${status} parses float whose integer part is safe as a number`, async () => {
+                const data = '{"float": 999999999999999.9}';
+                const okResponse = new Response(data, {status});
+                const result = await handleResponse(okResponse);
+                expect(result).toEqual({float: 999999999999999.9});
+            });
         });
 
         it(`${status} returns a promise resolved with the response body in text format if responseBodyFormat = "text"`, async () => {