🐛 fix(core): enable syntax diagnostics

lsp-server/test/test_core_server.py

@@ -340,6 +340,48 @@ def assert_framing(server: Path) -> None:
         raise RuntimeError("continuous framing should reach shutdown")
 
 
+def assert_diagnostics(server: Path) -> None:
+    client = LspClient(server)
+    try:
+        client.send({
+            "jsonrpc": "2.0",
+            "id": 41,
+            "method": "initialize",
+            "params": {},
+        })
+        if client.read().get("id") != 41:
+            raise RuntimeError("missing initialize response")
+
+        uri = "file:///diagnostics.tsl"
+        client.send({
+            "jsonrpc": "2.0",
+            "method": "textDocument/didOpen",
+            "params": {
+                "textDocument": {
+                    "uri": uri,
+                    "languageId": "tsl",
+                    "version": 1,
+                    "text": "function broken(",
+                },
+            },
+        })
+        diagnostics = client.read(timeout=1)
+        if diagnostics.get("method") != "textDocument/publishDiagnostics":
+            raise RuntimeError("didOpen should publish diagnostics")
+        params = diagnostics.get("params", {})
+        if params.get("uri") != uri or not params.get("diagnostics"):
+            raise RuntimeError("syntax diagnostics should identify the opened document")
+
+        client.send({"jsonrpc": "2.0", "id": 42, "method": "shutdown"})
+        if client.read().get("id") != 42:
+            raise RuntimeError("missing shutdown response")
+        client.send({"jsonrpc": "2.0", "method": "exit"})
+        if client.close_input() != 0:
+            raise RuntimeError("diagnostics sequence should shut down cleanly")
+    finally:
+        client.kill()
+
+
 def main() -> int:
     parser = argparse.ArgumentParser()
     parser.add_argument("--server", type=Path, required=True)
@@ -349,6 +391,7 @@ def main() -> int:
     assert_json_rpc_errors(args.server)
     assert_cancellation_and_failures(args.server)
     assert_framing(args.server)
+    assert_diagnostics(args.server)
     return 0