Add tests for SSR null loader values on non-executed loaders

packages/router/__tests__/router-test.ts

@@ -10560,6 +10560,57 @@ describe("a router", () => {
         });
       });
 
+      it("should fill in null loaderData values for routes without loaders", async () => {
+        let { query } = createStaticHandler([
+          {
+            id: "root",
+            path: "/",
+            children: [
+              {
+                id: "none",
+                path: "none",
+              },
+              {
+                id: "a",
+                path: "a",
+                loader: () => "A",
+                children: [
+                  {
+                    id: "b",
+                    path: "b",
+                  },
+                ],
+              },
+            ],
+          },
+        ]);
+
+        // No loaders at all
+        let context = await query(createRequest("/none"));
+        expect(context).toMatchObject({
+          actionData: null,
+          loaderData: {
+            root: null,
+            none: null,
+          },
+          errors: null,
+          location: { pathname: "/none" },
+        });
+
+        // Mix of loaders and no loaders
+        context = await query(createRequest("/a/b"));
+        expect(context).toMatchObject({
+          actionData: null,
+          loaderData: {
+            root: null,
+            a: "A",
+            b: null,
+          },
+          errors: null,
+          location: { pathname: "/a/b" },
+        });
+      });
+
       it("should support document load navigations returning responses", async () => {
         let { query } = createStaticHandler(SSR_ROUTES);
         let context = await query(createRequest("/parent/json"));

packages/router/router.ts

@@ -2345,6 +2345,7 @@ export function unstable_createStaticHandler(
     if (matchesToLoad.length === 0) {
       return {
         matches,
+        // Add a null for all matched routes for proper revalidation on the client
         loaderData: matches.reduce(
           (acc, m) => Object.assign(acc, { [m.route.id]: null }),
           {}
@@ -2375,11 +2376,11 @@ export function unstable_createStaticHandler(
       throw new Error(`${method}() call aborted`);
     }
 
-    // Can't do anything with these without the Remix side of things, so just
-    // cancel them for now
     let executedLoaders = new Set<string>();
     results.forEach((result, i) => {
       executedLoaders.add(matchesToLoad[i].route.id);
+      // Can't do anything with these without the Remix side of things, so just
+      // cancel them for now
       if (isDeferredResult(result)) {
         result.deferredData.cancel();
       }
@@ -2393,10 +2394,7 @@ export function unstable_createStaticHandler(
       pendingActionError
     );
 
-    // Add a null for any routes that didn't have loaders so we know they've been
-    // previously "executed" and qualify as a revalidation on subsequent
-    // invocations.  This is mostly needed for SSr scenarios where there may be
-    // no server loader but there may be a client loaders to fetch code split bundles
+    // Add a null for any non-loader matches for proper revalidation on the client
     matches.forEach((match) => {
       if (!executedLoaders.has(match.route.id)) {
         context.loaderData[match.route.id] = null;