fix(loader_tree): global, layout metadata correction

packages/next-swc/crates/next-core/src/app_structure.rs

@@ -723,6 +723,12 @@ async fn directory_tree_to_entrypoints_internal(
 
     // Capture the current page for the metadata to calculate segment relative to
     // the corresponding page for the static metadata files.
+    /*
+    let metadata = Metadata {
+        base_page: Some(app_page.clone()),
+        ..components.metadata.clone()
+    }; */
+
     let components = if components.metadata.base_page.is_some() {
         components
     } else {
@@ -740,6 +746,17 @@ async fn directory_tree_to_entrypoints_internal(
     let current_level_is_parallel_route = is_parallel_route(&directory_name);
 
     if let Some(page) = components.page {
+        // When resolving metadata with corresponding module
+        // (https://github.com/vercel/next.js/blob/aa1ee5995cdd92cc9a2236ce4b6aa2b67c9d32b2/packages/next/src/lib/metadata/resolve-metadata.ts#L340)
+        // layout takes precedence over page (https://github.com/vercel/next.js/blob/aa1ee5995cdd92cc9a2236ce4b6aa2b67c9d32b2/packages/next/src/server/lib/app-dir-module.ts#L22)
+        // If the component have layout and page both, do not attach same metadata to
+        // the page.
+        let metadata = if components.layout.is_some() {
+            Default::default()
+        } else {
+            components.metadata.clone()
+        };
+
         add_app_page(
             app_dir,
             &mut result,
@@ -751,7 +768,7 @@ async fn directory_tree_to_entrypoints_internal(
                     parallel_routes: IndexMap::new(),
                     components: Components {
                         page: Some(page),
-                        metadata: components.metadata.clone(),
+                        metadata,
                         ..Default::default()
                     }
                     .cell(),
@@ -769,7 +786,7 @@ async fn directory_tree_to_entrypoints_internal(
                             parallel_routes: IndexMap::new(),
                             components: Components {
                                 page: Some(page),
-                                metadata: components.metadata.clone(),
+                                metadata,
                                 ..Default::default()
                             }
                             .cell(),

packages/next-swc/crates/next-core/src/loader_tree.rs

@@ -159,7 +159,7 @@ impl LoaderTreeBuilder {
         &mut self,
         app_page: &AppPage,
         metadata: &Metadata,
-        global_metadata: &GlobalMetadata,
+        global_metadata: Option<&GlobalMetadata>,
     ) -> Result<()> {
         if metadata.is_empty() {
             return Ok(());
@@ -172,15 +172,26 @@ impl LoaderTreeBuilder {
             sitemap: _,
             base_page,
         } = metadata;
-        let GlobalMetadata {
-            favicon: _,
-            manifest,
-            robots: _,
-        } = global_metadata;
-
         let app_page = base_page.as_ref().unwrap_or(app_page);
         self.loader_tree_code += "  metadata: {";
 
+        // naively convert metadataitem -> metadatawithaltitem to iterate along with
+        // other icon items
+        let icon = if let Some(favicon) = global_metadata.and_then(|m| m.favicon) {
+            let item = match favicon {
+                MetadataItem::Static { path } => MetadataWithAltItem::Static {
+                    path,
+                    alt_path: None,
+                },
+                MetadataItem::Dynamic { path } => MetadataWithAltItem::Dynamic { path },
+            };
+            let mut item = vec![item];
+            item.extend(icon.iter());
+            item
+        } else {
+            icon.clone()
+        };
+
         self.write_metadata_items(app_page, "icon", icon.iter())
             .await?;
         self.write_metadata_items(app_page, "apple", apple.iter())
@@ -189,7 +200,11 @@ impl LoaderTreeBuilder {
             .await?;
         self.write_metadata_items(app_page, "openGraph", open_graph.iter())
             .await?;
-        self.write_metadata_manifest(*manifest).await?;
+
+        if let Some(global_metadata) = global_metadata {
+            self.write_metadata_manifest(global_metadata.manifest)
+                .await?;
+        }
         self.loader_tree_code += "  },";
         Ok(())
     }
@@ -350,7 +365,7 @@ impl LoaderTreeBuilder {
     }
 
     #[async_recursion]
-    async fn walk_tree(&mut self, loader_tree: Vc<LoaderTree>) -> Result<()> {
+    async fn walk_tree(&mut self, loader_tree: Vc<LoaderTree>, root: bool) -> Result<()> {
         use std::fmt::Write;
 
         let LoaderTree {
@@ -369,7 +384,7 @@ impl LoaderTreeBuilder {
         // add parallel_routes
         for (key, &parallel_route) in parallel_routes.iter() {
             write!(self.loader_tree_code, "{key}: ", key = StringifyJs(key))?;
-            self.walk_tree(parallel_route).await?;
+            self.walk_tree(parallel_route, false).await?;
             writeln!(self.loader_tree_code, ",")?;
         }
         writeln!(self.loader_tree_code, "}}, {{")?;
@@ -396,14 +411,23 @@ impl LoaderTreeBuilder {
             .await?;
         self.write_component(ComponentType::NotFound, *not_found)
             .await?;
-        self.write_metadata(app_page, metadata, &*global_metadata.await?)
-            .await?;
+
+        // Ensure global metadata being written only once at the root level
+        // Otherwise child pages will have redundant metadata
+        let global_metadata = &*global_metadata.await?;
+        self.write_metadata(
+            app_page,
+            metadata,
+            if root { Some(global_metadata) } else { None },
+        )
+        .await?;
+
         write!(self.loader_tree_code, "}}]")?;
         Ok(())
     }
 
     async fn build(mut self, loader_tree: Vc<LoaderTree>) -> Result<LoaderTreeModule> {
-        self.walk_tree(loader_tree).await?;
+        self.walk_tree(loader_tree, true).await?;
         Ok(LoaderTreeModule {
             imports: self.imports,
             loader_tree_code: self.loader_tree_code,