Bugfix ink_metadata: RootLayout must work for PortableForm (#1989)

The constructor `RootLayout::new()` needs to be generic to allow projects relying on working with PortableForm exclusively to re-use the ink! metadata.

CHANGELOG.md

@@ -63,6 +63,9 @@ You can see a more detailed log of changes below:
 - Use `decode_all`` for decoding cross contract call result - [#1810](https://github.com/paritytech/ink/pull/1810)
 - E2E: improve call API, remove `build_message` + callback - [#1782](https://github.com/paritytech/ink/pull/1782)
 
+### Fixed
+- `RootLayout::new()` is generic again to allow using `ink_metadata` in pure `PortableForm` contexts - [#1782](https://github.com/paritytech/ink/pull/1989)
+
 ## 4.3.0
 
 ### Fixed

crates/ink/codegen/src/generator/metadata.rs

@@ -76,11 +76,12 @@ impl Metadata<'_> {
         quote_spanned!(storage_span=>
             // Wrap the layout of the contract into the `RootLayout`, because
             // contract storage key is reserved for all packed fields
-            ::ink::metadata::layout::Layout::Root(::ink::metadata::layout::RootLayout::new::<#storage_ident, _>(
+            ::ink::metadata::layout::Layout::Root(::ink::metadata::layout::RootLayout::new(
                 #layout_key,
                 <#storage_ident as ::ink::storage::traits::StorageLayout>::layout(
                     &#key,
                 ),
+                ::ink::scale_info::meta_type::<#storage_ident>(),
             ))
         )
     }

crates/metadata/src/layout/mod.rs

@@ -154,32 +154,31 @@ impl IntoPortable for RootLayout {
 }
 
 impl RootLayout<MetaForm> {
-    /// Creates a new root layout.
-    pub fn new<Root, L>(root_key: LayoutKey, layout: L) -> Self
-    where
-        Root: TypeInfo + 'static,
-        L: Into<Layout<MetaForm>>,
-    {
-        Self {
-            root_key,
-            layout: Box::new(layout.into()),
-            ty: meta_type::<Root>(),
-        }
-    }
-
     /// Creates a new root layout with empty root type.
     pub fn new_empty<L>(root_key: LayoutKey, layout: L) -> Self
     where
         L: Into<Layout<MetaForm>>,
     {
-        Self::new::<(), L>(root_key, layout)
+        Self::new::<L>(root_key, layout, meta_type::<()>())
     }
 }
 
 impl<F> RootLayout<F>
 where
     F: Form,
 {
+    /// Create a new root layout
+    pub fn new<L>(root_key: LayoutKey, layout: L, ty: <F as Form>::Type) -> Self
+    where
+        L: Into<Layout<F>>,
+    {
+        Self {
+            root_key,
+            layout: Box::new(layout.into()),
+            ty,
+        }
+    }
+
     /// Returns the root key of the sub-tree.
     pub fn root_key(&self) -> &LayoutKey {
         &self.root_key

crates/metadata/src/layout/tests.rs

@@ -351,3 +351,12 @@ fn runtime_storage_layout_works() {
     );
     assert_eq!(json, expected);
 }
+
+#[test]
+fn ensure_portable_root_layout_are_supported() {
+    let root_key = LayoutKey::new(0u32);
+    let layout = Layout::Struct(StructLayout::new(String::new(), Vec::new()));
+    let ty = 0.into();
+
+    let _: RootLayout<PortableForm> = RootLayout::new(root_key, layout, ty);
+}

crates/storage/src/lazy/mapping.rs

@@ -369,9 +369,10 @@ const _: () = {
         KeyType: StorageKey + scale_info::TypeInfo + 'static,
     {
         fn layout(_: &Key) -> Layout {
-            Layout::Root(RootLayout::new::<Self, _>(
+            Layout::Root(RootLayout::new(
                 LayoutKey::from(&KeyType::KEY),
                 <V as StorageLayout>::layout(&KeyType::KEY),
+                scale_info::meta_type::<Self>(),
             ))
         }
     }

crates/storage/src/lazy/mod.rs

@@ -266,9 +266,10 @@ const _: () = {
         KeyType: StorageKey + scale_info::TypeInfo + 'static,
     {
         fn layout(_: &Key) -> Layout {
-            Layout::Root(RootLayout::new::<Self, _>(
+            Layout::Root(RootLayout::new(
                 LayoutKey::from(&KeyType::KEY),
                 <V as StorageLayout>::layout(&KeyType::KEY),
+                scale_info::meta_type::<Self>(),
             ))
         }
     }