fix: when ssg is enabled, the default render mode should be stream

Author: yimingjfe

packages/cli/plugin-ssg/src/server/index.ts

@@ -120,6 +120,7 @@ export const createServer = async (
           method: 'GET',
           headers: {
             host: 'localhost',
+            'x-modern-ssg-render': 'true',
           },
         });
 

packages/runtime/plugin-runtime/src/cli/code.ts

@@ -27,7 +27,7 @@ function getSSRMode(
   const { ssr, ssrByEntries } = config.server;
 
   if (config.output.ssg || config.output.ssgByEntries) {
-    return 'string';
+    return 'stream';
   }
 
   return checkSSRMode(ssrByEntries?.[entry] || ssr);

packages/runtime/plugin-runtime/src/core/server/requestHandler.tsx

@@ -143,7 +143,13 @@ function createSSRContext(
     config.ssr,
     config.ssrByEntries,
   );
-  const ssrMode = getSSRMode(ssrConfig);
+  let ssrMode = getSSRMode(ssrConfig);
+
+  // Force stream mode for SSG rendering
+  const isSsgRender = headers.get('x-modern-ssg-render') === 'true';
+  if (isSsgRender) {
+    ssrMode = 'stream';
+  }
 
   const loaderFailureMode =
     typeof ssrConfig === 'object' ? ssrConfig.loaderFailureMode : undefined;

packages/runtime/plugin-runtime/src/core/server/stream/createReadableStream.ts

@@ -36,7 +36,11 @@ export const createReadableStreamFromElement: CreateReadableStreamFromElement =
     // When a crawler visit the page, we should waiting for entrie content of page
 
     const isbot = checkIsBot(request.headers.get('user-agent'));
-    const onReady = isbot || forceStream2String ? 'onAllReady' : 'onShellReady';
+    const isSsgRender = request.headers.get('x-modern-ssg-render') === 'true';
+    const onReady =
+      isbot || isSsgRender || forceStream2String
+        ? 'onAllReady'
+        : 'onShellReady';
 
     const internalRuntimeContext = getGlobalInternalRuntimeContext();
     const hooks = internalRuntimeContext.hooks;

packages/runtime/plugin-runtime/src/core/server/stream/createReadableStream.worker.ts

@@ -56,8 +56,9 @@ export const createReadableStreamFromElement: CreateReadableStreamFromElement =
       });
 
       const isbot = checkIsBot(request.headers.get('user-agent'));
-      if (isbot) {
-        // However, when a crawler visits your page, or if you’re generating the pages at the build time,
+      const isSsgRender = request.headers.get('x-modern-ssg-render') === 'true';
+      if (isbot || isSsgRender) {
+        // However, when a crawler visits your page, or if you're generating the pages at the build time,
         // you might want to let all of the content load first and then produce the final HTML output instead of revealing it progressively.
         // from: https://react.dev/reference/react-dom/server/renderToReadableStream#handling-different-errors-in-different-ways
         await readableOriginal.allReady;