Fix (Async)SubstrateInterface.metadata

Author: thewhaleking

async_substrate_interface/async_substrate.py

@@ -823,6 +823,23 @@ async def initialize(self):
     async def __aexit__(self, exc_type, exc_val, exc_tb):
         pass
 
+    @property
+    def metadata(self):
+        warnings.warn(
+            "Calling AsyncSubstrateInterface.metadata is deprecated, as metadata is runtime-dependent, and it"
+            "can be unclear which for runtime you seek the metadata. You should instead use the specific runtime's "
+            "metadata. For now, the most recently used runtime will be given.",
+            category=DeprecationWarning,
+        )
+        runtime = self.runtime_cache.last_used
+        if not runtime or runtime.metadata is None:
+            raise AttributeError(
+                "Metadata not found. This generally indicates that the AsyncSubstrateInterface object "
+                "is not properly async initialized."
+            )
+        else:
+            return runtime.metadata
+
     @property
     async def properties(self):
         if self._properties is None:

async_substrate_interface/sync_substrate.py

@@ -566,6 +566,16 @@ def initialize(self):
     def __exit__(self, exc_type, exc_val, exc_tb):
         self.ws.close()
 
+    @property
+    def metadata(self):
+        if not self.runtime or self.runtime.metadata is None:
+            raise AttributeError(
+                "Metadata not found. This generally indicates that the AsyncSubstrateInterface object "
+                "is not properly async initialized."
+            )
+        else:
+            return self.runtime.metadata
+
     @property
     def properties(self):
         if self._properties is None:

async_substrate_interface/types.py

@@ -23,11 +23,13 @@ class RuntimeCache:
     blocks: dict[int, "Runtime"]
     block_hashes: dict[str, "Runtime"]
     versions: dict[int, "Runtime"]
+    last_used: Optional["Runtime"]
 
     def __init__(self):
         self.blocks = {}
         self.block_hashes = {}
         self.versions = {}
+        self.last_used = None
 
     def add_item(
         self,
@@ -36,6 +38,7 @@ def add_item(
         block_hash: Optional[str] = None,
         runtime_version: Optional[int] = None,
     ):
+        self.last_used = runtime
         if block is not None:
             self.blocks[block] = runtime
         if block_hash is not None:
@@ -49,14 +52,16 @@ def retrieve(
         block_hash: Optional[str] = None,
         runtime_version: Optional[int] = None,
     ) -> Optional["Runtime"]:
+        runtime = None
         if block is not None:
-            return self.blocks.get(block)
+            runtime = self.blocks.get(block)
         elif block_hash is not None:
-            return self.block_hashes.get(block_hash)
+            runtime = self.block_hashes.get(block_hash)
         elif runtime_version is not None:
-            return self.versions.get(runtime_version)
-        else:
-            return None
+            runtime = self.versions.get(runtime_version)
+        if runtime is not None:
+            self.last_used = runtime
+        return runtime
 
 
 class Runtime:
@@ -560,16 +565,6 @@ def chain(self):
         """
         return self._chain
 
-    @property
-    def metadata(self):
-        if not self.runtime or self.runtime.metadata is None:
-            raise AttributeError(
-                "Metadata not found. This generally indicates that the AsyncSubstrateInterface object "
-                "is not properly async initialized."
-            )
-        else:
-            return self.runtime.metadata
-
     @property
     def implements_scaleinfo(self) -> Optional[bool]:
         """