test: add end-to-end semantic tokens test

tests/e2e/test_semantic_tokens.py

@@ -0,0 +1,121 @@
+############################################################################
+# Copyright(c) Open Law Library. All rights reserved.                      #
+# See ThirdPartyNotices.txt in the project root for additional notices.    #
+#                                                                          #
+# Licensed under the Apache License, Version 2.0 (the "License")           #
+# you may not use this file except in compliance with the License.         #
+# You may obtain a copy of the License at                                  #
+#                                                                          #
+#     http: // www.apache.org/licenses/LICENSE-2.0                         #
+#                                                                          #
+# Unless required by applicable law or agreed to in writing, software      #
+# distributed under the License is distributed on an "AS IS" BASIS,        #
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. #
+# See the License for the specific language governing permissions and      #
+# limitations under the License.                                           #
+############################################################################
+from __future__ import annotations
+
+import typing
+
+import pytest
+import pytest_asyncio
+from lsprotocol import types
+
+if typing.TYPE_CHECKING:
+    from typing import List, Tuple
+
+    from pygls.lsp.client import BaseLanguageClient
+
+
+@pytest_asyncio.fixture(scope="module")
+async def semantic_tokens(get_client_for):
+    async for result in get_client_for("semantic_tokens.py"):
+        yield result
+
+
+@pytest.mark.parametrize(
+    "text,expected",
+    [
+        # Just a handful of cases to check we've got the basics right
+        ("fn", [0, 0, 2, 0, 0]),
+        ("type", [0, 0, 4, 0, 0]),
+        ("Rectangle", [0, 0, 9, 5, 0]),
+        (
+            "type Rectangle",
+            [
+                # fmt: off
+            0, 0, 4, 0, 0,
+            0, 5, 9, 5, 8,
+                # fmt: on
+            ],
+        ),
+        (
+            "fn area",
+            [
+                # fmt: off
+            0, 0, 2, 0, 0,
+            0, 3, 4, 2, 8,
+                # fmt: on
+            ],
+        ),
+        (
+            "fn\n area",
+            [
+                # fmt: off
+            0, 0, 2, 0, 0,
+            1, 1, 4, 2, 8,
+                # fmt: on
+            ],
+        ),
+    ],
+)
+@pytest.mark.asyncio(scope="module")
+async def test_semantic_tokens_full(
+    semantic_tokens: Tuple[BaseLanguageClient, types.InitializeResult],
+    uri_for,
+    path_for,
+    text: str,
+    expected: List[int],
+):
+    """Ensure that the example semantic tokens server is working as expected."""
+    client, initialize_result = semantic_tokens
+
+    semantic_tokens_options = initialize_result.capabilities.semantic_tokens_provider
+    assert semantic_tokens_options.full is True
+
+    legend = semantic_tokens_options.legend
+    assert legend.token_types == [
+        "keyword",
+        "variable",
+        "function",
+        "operator",
+        "parameter",
+        "type",
+    ]
+    assert legend.token_modifiers == [
+        "deprecated",
+        "readonly",
+        "defaultLibrary",
+        "definition",
+    ]
+
+    test_uri = uri_for("code.txt")
+
+    client.text_document_did_open(
+        types.DidOpenTextDocumentParams(
+            types.TextDocumentItem(
+                uri=test_uri,
+                language_id="plaintext",
+                version=0,
+                text=text,
+            )
+        )
+    )
+
+    response = await client.text_document_semantic_tokens_full_async(
+        types.SemanticTokensParams(
+            text_document=types.TextDocumentIdentifier(uri=test_uri),
+        )
+    )
+    assert response.data == expected