Fixed diagnostics files uri handling, added low-level tests

test/solidlsp/fsharp/test_fsharp_basic.py

@@ -9,6 +9,7 @@ from solidlsp.ls_config import Language
 from solidlsp.ls_utils import SymbolUtils
 from test.conftest import find_identifier_position, get_repo_path, is_ci, language_has_verified_implementation_support
 from test.solidlsp.conftest import format_symbol_for_assert, has_malformed_name, request_all_symbols
+from test.solidlsp.util.diagnostics import assert_file_diagnostics
 
 
 # Currently, most F# tests fail, there seems to be a regression or instability.
@@ -196,21 +197,13 @@ class TestFSharpLanguageServer:
         assert isinstance(result["value"], list), "Completions should be a list"
 
     @pytest.mark.parametrize("language_server", [Language.FSHARP], indirect=True)
-    def test_diagnostics(self, language_server: SolidLanguageServer) -> None:
-        """Test getting diagnostics (errors, warnings) from F# files."""
-        file_path = os.path.join("Program.fs")
-
-        # FsAutoComplete uses publishDiagnostics notifications instead of textDocument/diagnostic requests
-        # So we'll test that the language server can handle files without crashing
-        # In real usage, diagnostics would come through the publishDiagnostics notification handler
-
-        # Test that we can at least work with the file (open/close cycle)
-        with language_server.open_file(file_path) as _:
-            # If we can open and close the file without errors, basic diagnostics support is working
-            pass
-
-        # This is a successful test - FsAutoComplete is working with F# files
-        assert True, "F# language server can handle files successfully"
+    def test_file_diagnostics(self, language_server: SolidLanguageServer) -> None:
+        assert_file_diagnostics(
+            language_server,
+            "DiagnosticsSample.fs",
+            (),
+            min_count=1,
+        )
 
     @pytest.mark.parametrize("language_server", [Language.FSHARP], indirect=True)
     def test_bare_symbol_names(self, language_server) -> None: