fix: catch RecursionError in initialization

fortls/langserver.py

@@ -1489,7 +1489,14 @@ def workspace_init(self):
         pool.close()
         pool.join()
         for path, result in results.items():
-            result_obj = result.get()
+            try:
+                result_obj = result.get()
+            except Exception as e:
+                result_obj = (
+                    "An exception has occured while initialising the workspace.\n"
+                    f"Exception({(type(e))}): {e}\n"
+                    + f"Traceback: {traceback.format_exc()}"
+                )
             if isinstance(result_obj, str):
                 self.post_message(
                     f"Initialization failed for file {path}: {result_obj}"

test/test_server_init.py

@@ -0,0 +1,32 @@
+import os
+import tempfile
+
+import pytest
+from setup_tests import Path, run_request, write_rpc_request
+
+from fortls.constants import Severity
+
+
+@pytest.fixture()
+def setup_tmp_file():
+    levels = 2000
+    fd, filename = tempfile.mkstemp(suffix=".f90")
+    try:
+        with os.fdopen(fd, "w") as tmp:
+            tmp.write(
+                "program nested_if\n"
+                + str("if (.true.) then\n" * levels)
+                + str("end if\n" * levels)
+                + "end program nested_if"
+            )
+        yield filename
+    finally:
+        os.remove(filename)
+
+
+def test_recursion_error_handling(setup_tmp_file):
+    root = Path(setup_tmp_file).parent
+    request_string = write_rpc_request(1, "initialize", {"rootPath": str(root)})
+    errcode, results = run_request(request_string)
+    assert errcode == 0
+    assert results[0]["type"] == Severity.error