🐛 fix(core): dispatch cancellable requests asynchronously

lsp-server/test/test_core_server.py

@@ -184,7 +184,6 @@ def assert_json_rpc_errors(server: Path) -> None:
             "method": "initialize",
             "params": {},
         }),
-        frame({"jsonrpc": "2.0", "id": 9, "method": "missing/method"}),
         frame({"jsonrpc": "2.0", "id": 10, "method": "shutdown"}),
         frame({"jsonrpc": "2.0", "method": "exit"}),
     ])
@@ -204,8 +203,95 @@ def assert_json_rpc_errors(server: Path) -> None:
         raise RuntimeError("A non-object JSON value should return InvalidRequest")
     if response_by_id(result.stdout, 7).get("error", {}).get("code") != -32600:
         raise RuntimeError("jsonrpc other than 2.0 should return InvalidRequest")
-    if response_by_id(result.stdout, 9).get("error", {}).get("code") != -32601:
-        raise RuntimeError("Unknown request method should return MethodNotFound")
+    client = LspClient(server)
+    try:
+        client.send({
+            "jsonrpc": "2.0",
+            "id": 11,
+            "method": "initialize",
+            "params": {},
+        })
+        client.read()
+        client.send({"jsonrpc": "2.0", "id": 9, "method": "missing/method"})
+        if client.read().get("error", {}).get("code") != -32601:
+            raise RuntimeError("Unknown request method should return MethodNotFound")
+        client.send({"jsonrpc": "2.0", "id": 12, "method": "shutdown"})
+        client.read()
+        client.send({"jsonrpc": "2.0", "method": "exit"})
+        if client.close_input() != 0:
+            raise RuntimeError("unknown method sequence should shut down cleanly")
+    finally:
+        client.kill()
+
+
+def assert_cancellation_and_failures(server: Path) -> None:
+    client = LspClient(server)
+    try:
+        client.send({
+            "jsonrpc": "2.0",
+            "id": 1,
+            "method": "initialize",
+            "params": {},
+        })
+        if client.read().get("id") != 1:
+            raise RuntimeError("missing initialize response")
+
+        client.send({"jsonrpc": "2.0", "id": 2, "method": "test/block"})
+        client.send({"jsonrpc": "2.0", "id": "2", "method": "test/block"})
+        client.send({
+            "jsonrpc": "2.0",
+            "method": "$/cancelRequest",
+            "params": {"id": 2},
+        })
+        cancelled = client.read(timeout=1)
+        if cancelled.get("id") != 2 or \
+                cancelled.get("error", {}).get("code") != -32800:
+            raise RuntimeError("integer request id should be cancelled independently")
+
+        client.send({
+            "jsonrpc": "2.0",
+            "method": "$/cancelRequest",
+            "params": {"id": "2"},
+        })
+        string_cancelled = client.read(timeout=1)
+        if string_cancelled.get("id") != "2" or \
+                string_cancelled.get("error", {}).get("code") != -32800:
+            raise RuntimeError("string request id should be cancelled independently")
+
+        client.send({"jsonrpc": "2.0", "id": 3, "method": "test/throw"})
+        failed = client.read(timeout=1)
+        if failed.get("id") != 3 or \
+                failed.get("error", {}).get("code") != -32603:
+            raise RuntimeError("request exceptions should return InternalError")
+
+        client.send({"jsonrpc": "2.0", "id": 4, "method": "test/block"})
+        client.send({"jsonrpc": "2.0", "id": 4, "method": "test/block"})
+        duplicate = client.read(timeout=1)
+        if duplicate.get("id") != 4 or \
+                duplicate.get("error", {}).get("code") != -32600:
+            raise RuntimeError("duplicate active request id should return InvalidRequest")
+
+        client.send({
+            "jsonrpc": "2.0",
+            "method": "$/cancelRequest",
+            "params": {"id": 4},
+        })
+        cancelled_original = client.read(timeout=1)
+        if cancelled_original.get("id") != 4 or \
+                cancelled_original.get("error", {}).get("code") != -32800:
+            raise RuntimeError("duplicate id must not replace the original request")
+
+        client.send({"jsonrpc": "2.0", "method": "test/throwNotification"})
+        client.send({"jsonrpc": "2.0", "id": 5, "method": "shutdown"})
+        shutdown = client.read(timeout=1)
+        if shutdown.get("id") != 5 or shutdown.get("result", "missing") is not None:
+            raise RuntimeError("notification exception should not stop the server")
+
+        client.send({"jsonrpc": "2.0", "method": "exit"})
+        if client.close_input() != 0:
+            raise RuntimeError("fixture should exit cleanly after cancellation tests")
+    finally:
+        client.kill()
 
 
 def main() -> int:
@@ -215,6 +301,7 @@ def main() -> int:
 
     assert_lifecycle(args.server)
     assert_json_rpc_errors(args.server)
+    assert_cancellation_and_failures(args.server)
     return 0