fix(core): preserve numeric header values in headersToDict

Author: isaacs

packages/core/src/utils/request.ts

@@ -70,6 +70,8 @@ export function headersToDict(
     Object.entries(reqHeaders).forEach(([key, value]) => {
       if (typeof value === 'string') {
         headers[key] = value;
+      } else if (typeof value === 'number') {
+        headers[key] = String(value);
       }
     });
   } catch {

packages/core/test/lib/utils/request.test.ts

@@ -49,6 +49,19 @@ describe('request utils', () => {
         key3: 'value3',
       });
     });
+
+    it('stringifies numeric values (e.g. OutgoingHttpHeaders content-length)', () => {
+      expect(
+        headersToDict({
+          'content-length': 42,
+          'x-string': 'hello',
+          'x-undef': undefined,
+        }),
+      ).toEqual({
+        'content-length': '42',
+        'x-string': 'hello',
+      });
+    });
   });
 
   describe('winterCGRequestToRequestData', () => {