Enhance visitor country handling by prioritizing forwarded header on revalidation requests

.changeset/send-visitor-country.md

@@ -2,4 +2,4 @@
 "gitbook": patch
 ---
 
-Send the visitor country to resolvePublishedContentByUrl on dev, preview, staging and selected sites.
+Send the visitor country to resolvePublishedContentByUrl on dev, preview, staging and selected sites, using the forwarded `x-gitbook-country` header on revalidation requests.

packages/gitbook/src/lib/visitors.test.ts

@@ -628,6 +628,38 @@ describe('getVisitorCountry', () => {
     it('should return undefined when no country header is present', () => {
         expect(getVisitorCountry(requestWith({}))).toBeUndefined();
     });
+
+    it('should prefer the forwarded country header on revalidation requests', () => {
+        expect(
+            getVisitorCountry(
+                requestWith({
+                    'user-agent': 'gitbook-open-revalidation-worker',
+                    'x-gitbook-country': 'DE',
+                    'x-open-next-country': 'FR',
+                })
+            )
+        ).toBe('DE');
+    });
+
+    it('should ignore the forwarded country header outside revalidation requests', () => {
+        expect(
+            getVisitorCountry(
+                requestWith({ 'x-gitbook-country': 'DE', 'x-open-next-country': 'FR' })
+            )
+        ).toBe('FR');
+        expect(getVisitorCountry(requestWith({ 'x-gitbook-country': 'DE' }))).toBeUndefined();
+    });
+
+    it('should fall back to geolocation headers on revalidation requests without a forwarded country', () => {
+        expect(
+            getVisitorCountry(
+                requestWith({
+                    'user-agent': 'gitbook-open-revalidation-worker',
+                    'x-open-next-country': 'FR',
+                })
+            )
+        ).toBe('FR');
+    });
 });
 
 describe('shouldSendVisitorCountry', () => {

packages/gitbook/src/lib/visitors.ts

@@ -124,10 +124,13 @@ export function shouldSendVisitorCountry(
 }
 
 /**
- * Get the ISO 3166-1 alpha-2 country code of the visitor from the geolocation headers.
+ * Get the ISO 3166-1 alpha-2 country code of the visitor from the geolocation headers,
+ * or from `x-gitbook-country` when the request comes from the revalidation worker.
  */
 export function getVisitorCountry(request: { headers: Headers }): string | undefined {
+    // The revalidation worker forwards the original visitor country; only trust it from there.
     const country = (
+        (isRevalidationRequest(request.headers) && request.headers.get('x-gitbook-country')) ||
         request.headers.get('x-open-next-country') ||
         request.headers.get('x-vercel-ip-country') ||
         ''