Enable ty rule 'unresolved-attribute' for test/

pyproject.toml

@@ -152,7 +152,6 @@ no-matching-overload = "ignore"
 not-subscriptable = "ignore"
 parameter-already-assigned = "ignore"
 too-many-positional-arguments = "ignore"
-unresolved-attribute = "ignore"
 unsupported-operator = "ignore"
 
 [tool.poe.env]

test/serena/test_fs_api.py

@@ -73,9 +73,9 @@ def test_list_dir_and_find_file(api: FsApi) -> None:
 def test_search_for_pattern(api: FsApi) -> None:
     matches = api.search_for_pattern("foo", relative_path="src")
     assert len(matches) == 3
-    assert {m.source_file_path.replace("\\", "/") for m in matches.matches} == {"src/a.py", "src/b.txt"}
+    assert {m.source_file_path.replace("\\", "/") for m in matches.matches} == {"src/a.py", "src/b.txt"}  # type: ignore
 
     # restricting to code files excludes the text file; the rendering maps files to matched lines
     code_matches = api.search_for_pattern("foo", restrict_search_to_code_files=True)
-    assert all(m.source_file_path.endswith("a.py") for m in code_matches.matches)
+    assert all(m.source_file_path.endswith("a.py") for m in code_matches.matches)  # type: ignore
     assert "foo(1)" in code_matches.represent()

test/serena/test_ls_file_sync.py

@@ -62,7 +62,8 @@ class FileSystemSyncTestCase:
                 symbol_names = [ref["name_path"].split("/")[-1] for ref in ref_symbols]
                 return symbol_names
         else:
-            ls = next(iter(agent.get_active_project_or_raise().language_server_manager.iter_language_servers()))
+            ls_manager = agent.get_active_project_or_raise().get_language_server_manager_or_raise()
+            ls = next(iter(ls_manager.iter_language_servers()))
             document_symbols = ls.request_document_symbols(self._TARGET_FILE).get_all_symbols_and_roots()
             target = next((s for s in document_symbols[0] if s.get("name") == self._TARGET_SYMBOL), None)
             assert target is not None and "selectionRange" in target, f"{self._TARGET_SYMBOL} not found in {self._TARGET_FILE}"
@@ -162,7 +163,9 @@ class SymbolPositionStaleAfterExternalEditTestCase:
 
         with agent_for_project_context(LanguageServerId.PYTHON, str(repo_root)) as agent:
             project = agent.get_active_project_or_raise()
-            ls = next(iter(project.language_server_manager.iter_language_servers()))
+            ls_manager = project.language_server_manager
+            assert ls_manager is not None
+            ls = next(iter(ls_manager.iter_language_servers()))
             tool = agent.get_tool(FindSymbolTool)
 
             # Hold the file's buffer open across the external edit, mirroring the state left

test/serena/test_serena_agent.py

@@ -833,7 +833,7 @@ def parse_edit_diagnostics_result(result: str) -> dict:
 @contextmanager
 def project_file_modification_context(serena_agent: SerenaAgent, relative_path: str) -> Iterator[None]:
     """Context manager to modify a project file and revert the changes after use."""
-    project = serena_agent.get_active_project()
+    project = serena_agent.get_active_project_or_raise()
     file_path = os.path.join(project.project_root, relative_path)
 
     # Read the original content
@@ -1455,6 +1455,7 @@ class TestPromptProvision:
 
         # now activate another project which dynamically enables a new mode (no-onboarding)
         reg_project = serena_agent.serena_config.get_registered_project(project_name2)
+        assert reg_project is not None
         reg_project.project_config.default_modes = ["no-onboarding"]
         expected_new_mode_message = "The onboarding process is not applied."
         result2 = self._call_tool(serena_agent, ActivateProjectTool, project=project_name2, session_id=session1)

test/serena/test_symbol.py

@@ -251,10 +251,10 @@ class TestSymbolDictTypes:
         :param key_type: the corresponding key type (Literal[...]) that the dict should have for keys
         """
         dict_type_keys = dict_type.__annotations__.keys()
-        assert len(dict_type_keys) == len(key_type.__args__), (
-            f"Expected {len(key_type.__args__)} keys in {dict_type}, but got {len(dict_type_keys)}"
+        assert len(dict_type_keys) == len(key_type.__args__), (  # type: ignore
+            f"Expected {len(key_type.__args__)} keys in {dict_type}, but got {len(dict_type_keys)}"  # type: ignore
         )
-        for expected_key in key_type.__args__:
+        for expected_key in key_type.__args__:  # type: ignore
             assert expected_key in dict_type_keys, f"Expected key '{expected_key}' not found in {dict_type}"
 
     def test_ls_symbol_dict_type(self):

test/solidlsp/al/test_al_basic.py

@@ -264,7 +264,7 @@ class TestALHoverInjection:
                 char = start.get("character", 0)
                 hover = language_server.request_hover(file_path, line, char)
                 if hover and "contents" in hover:
-                    return hover, hover["contents"].get("value", "")
+                    return hover, hover["contents"].get("value", "")  # type: ignore
                 return hover, None
         return None, None
 
@@ -286,7 +286,7 @@ class TestALHoverInjection:
                         char = start.get("character", 0)
                         hover = language_server.request_hover(file_path, line, char)
                         if hover and "contents" in hover:
-                            return hover, hover["contents"].get("value", "")
+                            return hover, hover["contents"].get("value", "")  # type: ignore
                         return hover, None
         return None, None
 
@@ -373,7 +373,7 @@ class TestALHoverInjection:
                                 hover = language_server.request_hover(file_path, line, char)
 
                                 assert hover is not None, "Hover should return a result for field"
-                                value = hover.get("contents", {}).get("value", "")
+                                value = hover.get("contents", {}).get("value", "")  # type: ignore
                                 # Field hover should NOT start with ** (no injection)
                                 assert not value.startswith("**"), f"Field hover should not have injected name. Got: {value[:200]}"
                                 return
@@ -445,7 +445,7 @@ class TestALPathNormalization:
 
                 hover = language_server.request_hover(file_path, line, char)
                 assert hover is not None, "Hover should return a result"
-                value = hover.get("contents", {}).get("value", "")
+                value = hover.get("contents", {}).get("value", "")  # type: ignore
                 assert '**Table 50000 "TEST Customer"**' in value, f"Hover should have injection. Got: {value[:200]}"
                 return
 
@@ -466,7 +466,7 @@ class TestALPathNormalization:
 
                 hover = language_server.request_hover(file_path, line, char)
                 assert hover is not None, "Hover should return a result"
-                value = hover.get("contents", {}).get("value", "")
+                value = hover.get("contents", {}).get("value", "")  # type: ignore
                 assert '**Table 50000 "TEST Customer"**' in value, f"Hover should have injection. Got: {value[:200]}"
                 return
 
@@ -491,7 +491,7 @@ class TestALPathNormalization:
                 # Request hover with forward slash path (different format)
                 hover = language_server.request_hover(file_path_forward, line, char)
                 assert hover is not None, "Hover should return a result"
-                value = hover.get("contents", {}).get("value", "")
+                value = hover.get("contents", {}).get("value", "")  # type: ignore
                 assert '**Table 50000 "TEST Customer"**' in value, (
                     f"Hover injection should work with mixed path formats. Got: {value[:200]}"
                 )
@@ -518,7 +518,7 @@ class TestALPathNormalization:
                 # Request hover with backslash path (different format)
                 hover = language_server.request_hover(file_path_backslash, line, char)
                 assert hover is not None, "Hover should return a result"
-                value = hover.get("contents", {}).get("value", "")
+                value = hover.get("contents", {}).get("value", "")  # type: ignore
                 assert '**Table 50000 "TEST Customer"**' in value, (
                     f"Hover injection should work with mixed path formats. Got: {value[:200]}"
                 )
@@ -553,7 +553,7 @@ class TestALPathNormalization:
                     # Request hover with different path format
                     hover = language_server.request_hover(hover_path, line, char)
                     assert hover is not None, f"Hover should return a result for {symbol_name}"
-                    value = hover.get("contents", {}).get("value", "")
+                    value = hover.get("contents", {}).get("value", "")  # type: ignore
                     assert f"**{expected_injection}**" in value, (
                         f"Hover for {symbol_name} should have injection with mixed paths. Got: {value[:200]}"
                     )

test/solidlsp/angular/test_angular_basic.py

@@ -125,6 +125,7 @@ class TestAngularLanguageServerBasics:
         # +1 puts the cursor inside the identifier rather than on its leading boundary.
         refs = language_server.request_references(src_path, coords.line, coords.col + 1)
         ref_paths = {r.get("relativePath", "") for r in refs}
+        ref_paths = {p for p in ref_paths if p}  # filter out any empty relativePath entries
         assert any(p.endswith("app.component.html") for p in ref_paths), (
             f"Expected references for setName to include its template callsite in app.component.html, got: {ref_paths}"
         )

test/solidlsp/angular/test_angular_error_cases.py

@@ -21,6 +21,7 @@ import time
 import pytest
 
 from solidlsp import SolidLanguageServer
+from solidlsp.language_servers.angular_language_server import AngularLanguageServer
 from solidlsp.ls_config import LanguageServerId
 from solidlsp.ls_exceptions import SolidLSPException
 from test.conftest import _create_ls
@@ -344,6 +345,7 @@ class TestAngularStartupCleanup:
             with pytest.raises(RuntimeError, match="simulated ngserver init"):
                 ls.start()
 
+            assert isinstance(ls, AngularLanguageServer)
             assert ls._ts_server is None, "TS companion was not cleared after startup failure"
             assert ls._html_server is None, "HTML companion was not cleared after startup failure"
 

test/solidlsp/clojure/test_clojure_indexing.py

@@ -54,7 +54,7 @@ class TestClojureProjectIndexing:
 
         # extra.clj contains two real call sites (in double-product and triple-product);
         # they must be returned regardless of whether the file was opened beforehand
-        extra_refs = [r for r in refs if r.get("relativePath", "").endswith("extra.clj")]
+        extra_refs = [r for r in refs if r.get("relativePath", "").endswith("extra.clj")]  # type: ignore
         assert extra_refs, (
             "Expected references to 'multiply' to include call sites from extra.clj, "
             f"but got files: {sorted(ref_paths)}. "
@@ -82,7 +82,9 @@ class TestClojureProjectIndexing:
         ref_paths = {r.get("relativePath", "") for r in refs}
 
         consumer_refs = [
-            r for r in refs if r.get("relativePath", "").replace("\\", "/").endswith("sub_module/src/sub_module_app/consumer.clj")
+            r
+            for r in refs
+            if r.get("relativePath", "").replace("\\", "/").endswith("sub_module/src/sub_module_app/consumer.clj")  # type: ignore
         ]
         assert consumer_refs, (
             "Expected references to 'multiply' to include call sites from the sibling module "

test/solidlsp/crystal/test_crystal_basic.py

@@ -14,6 +14,7 @@ import os
 import pytest
 
 from solidlsp import SolidLanguageServer
+from solidlsp.language_servers.crystal_language_server import CrystalLanguageServer
 from solidlsp.ls_config import LanguageServerId
 from test.conftest import language_server_tests_enabled
 from test.solidlsp.conftest import format_symbol_for_assert, has_malformed_name, request_all_symbols
@@ -94,7 +95,8 @@ class TestCrystalDefinition:
         file_path = os.path.join("src", "main.cr")
 
         # wait for Crystalline to compile the project
-        language_server.language_server._wait_for_compilation()
+        assert isinstance(language_server, CrystalLanguageServer)
+        language_server._wait_for_compilation()
 
         # Calculator.new on line 35 (0-indexed: 34), col 13 -> Calculator class on line 3 (0-indexed: 2)
         definitions = language_server.request_definition(file_path, 34, 13)

test/solidlsp/dart/test_dart_basic.py

@@ -249,6 +249,7 @@ class TestDartLanguageServer:
         # Find coordinates of 'final result = a + b;' - test position on 'result'
         with language_server.open_file(file_path, open_in_ls=False) as f:
             pos = find_text_coordinates(f.contents, r"final (result) = a \+ b;")
+            assert pos is not None
 
         defining_symbol = language_server.request_defining_symbol(file_path, pos.line, pos.col)
 

test/solidlsp/erlang/test_erlang_ignored_dirs.py

@@ -4,6 +4,7 @@ from pathlib import Path
 import pytest
 
 from solidlsp import SolidLanguageServer
+from solidlsp.language_servers.erlang_language_server import ErlangLanguageServer
 from solidlsp.ls_config import LanguageServerId
 from test.conftest import language_server_tests_enabled, start_ls_context
 
@@ -146,6 +147,8 @@ def test_symbol_tree_excludes_build_dirs(language_server: SolidLanguageServer):
 @pytest.mark.parametrize("language_server", [LanguageServerId.ERLANG], indirect=True)
 def test_ignore_compiled_files(language_server: SolidLanguageServer):
     """Test that compiled Erlang files are ignored."""
+    assert isinstance(language_server, ErlangLanguageServer)
+
     # Test that beam files are ignored
     assert language_server.is_ignored_filename("module.beam"), "BEAM files should be ignored"
     assert language_server.is_ignored_filename("app.beam"), "BEAM files should be ignored"
@@ -164,6 +167,7 @@ def test_rebar_directories_ignored(language_server: SolidLanguageServer):
     assert language_server.is_ignored_dirname(".rebar3"), "rebar3 cache should be ignored"
 
     # Test that rebar.lock and rebar.config are not ignored (they are configuration files)
+    assert isinstance(language_server, ErlangLanguageServer)
     assert not language_server.is_ignored_filename("rebar.config"), "rebar.config should not be ignored"
     assert not language_server.is_ignored_filename("rebar.lock"), "rebar.lock should not be ignored"
 

test/solidlsp/julia/test_fatou.py

@@ -25,7 +25,7 @@ class TestFatouLanguageServer:
     def test_cross_file_references(self, language_server: SolidLanguageServer) -> None:
         references = language_server.request_references("src/fatou_a.jl", line=0, column=2)
 
-        locations = {(reference["relativePath"].replace("\\", "/"), reference["range"]["start"]["line"]) for reference in references}
+        locations = {(reference["relativePath"].replace("\\", "/"), reference["range"]["start"]["line"]) for reference in references}  # type: ignore
         assert locations >= {("src/fatou_a.jl", 1), ("src/fatou_b.jl", 0)}
 
     def test_file_matching(self) -> None:

test/solidlsp/pascal/test_pascal_basic.py

@@ -192,7 +192,7 @@ class TestPascalLanguageServerBasics:
             contents = hover.get("contents", {})
             value = contents.get("value", "") if isinstance(contents, dict) else str(contents)
         else:
-            value = hover.contents.value if hasattr(hover.contents, "value") else str(hover.contents)
+            value = hover.contents.value if hasattr(hover.contents, "value") else str(hover.contents)  # type: ignore
 
         # Should contain the function signature
         assert "CalculateSum" in value, f"Hover should show function name. Got: {value[:500]}"

test/solidlsp/python/test_symbol_retrieval.py

@@ -46,6 +46,7 @@ class TestLanguageServerSymbols:
         with language_server.open_file(file_path, open_in_ls=False) as f:
             file_content = f.contents
         coords = find_text_coordinates(file_content, r"(status): str")
+        assert coords is not None
         ref_symbols = [ref.symbol for ref in language_server.request_referencing_symbols(file_path, coords.line, coords.col)]
 
         assert len(ref_symbols) > 0

test/solidlsp/ruby/test_ruby_symbol_retrieval.py

@@ -590,7 +590,9 @@ class TestRubyLanguageServerSymbols:
             pos = find_text_coordinates(fb.contents, r"user = @service\.(create_user)")
 
         # Verify that we can find the method definition
+        assert pos is not None
         defining_symbol = language_server.request_defining_symbol(file_path, pos.line, pos.col)
+        assert defining_symbol is not None
         assert "name" in defining_symbol
         assert "kind" in defining_symbol
         assert defining_symbol.get("name") == "create_user"

test/solidlsp/rust/test_rust_basic.py

@@ -68,7 +68,7 @@ class TestRustLanguageServer:
 
             implementations = language_server.request_implementation(os.path.join("src", "lib.rs"), *pos)
             assert implementations, "Expected at least one implementation of Greeter.format_greeting"
-            assert any("src/lib.rs" in implementation.get("relativePath", "").replace("\\", "/") for implementation in implementations), (
+            assert any("src/lib.rs" in implementation.get("relativePath", "").replace("\\", "/") for implementation in implementations), (  # type: ignore
                 f"Expected ConsoleGreeter.format_greeting in implementations, got: {implementations}"
             )
 
@@ -81,7 +81,7 @@ class TestRustLanguageServer:
             implementing_symbols = language_server.request_implementing_symbols(os.path.join("src", "lib.rs"), *pos)
             assert implementing_symbols, "Expected implementing symbols for Greeter.format_greeting"
             assert any(
-                symbol.get("name") == "format_greeting" and "src/lib.rs" in symbol["location"].get("relativePath", "").replace("\\", "/")
+                symbol.get("name") == "format_greeting" and "src/lib.rs" in symbol["location"].get("relativePath", "").replace("\\", "/")  # type: ignore
                 for symbol in implementing_symbols
             ), f"Expected ConsoleGreeter.format_greeting symbol, got: {implementing_symbols}"
 

test/solidlsp/scss/test_scss_basic.py

@@ -130,6 +130,7 @@ class TestScssReferences:
         line, col = coords.line, coords.col
         refs = language_server.request_references(path, line, col + 2)
         ref_paths = {r.get("relativePath", "") for r in refs}
+        ref_paths = {r for r in ref_paths if r}  # filter out empty strings
         assert any(p.endswith("buttons.scss") for p in ref_paths), (
             f"Expected card-surface references to include buttons.scss, got: {ref_paths}"
         )
@@ -148,6 +149,7 @@ class TestScssReferences:
         line, col = coords.line, coords.col
         refs = language_server.request_references(path, line, col + 2)
         ref_paths = {r.get("relativePath", "") for r in refs}
+        ref_paths = {r for r in ref_paths if r}  # filter out empty strings
         assert any(p.endswith("buttons.scss") for p in ref_paths), (
             f"Expected $color-primary references to include buttons.scss, got: {ref_paths}"
         )

test/solidlsp/svelte/test_svelte_basic.py

@@ -20,7 +20,7 @@ class TestSvelteLanguageServer:
     def test_svelte_language_server_root_matches_repo_path(self, language_server: SolidLanguageServer, repo_path: Path) -> None:
         assert language_server.is_running()
         assert repo_path.resolve() == svelte_test_conftest.repo_path.resolve()
-        assert Path(language_server.language_server.repo_path).resolve() == repo_path.resolve()
+        assert Path(language_server.repository_root_path).resolve() == repo_path.resolve()
 
     @pytest.mark.parametrize("language_server", [LanguageServerId.SVELTE], indirect=True)
     def test_svelte_and_typescript_files_in_symbol_tree(self, language_server: SolidLanguageServer) -> None:
@@ -74,12 +74,13 @@ class TestSvelteLanguageServer:
     def test_definition_from_component_import_to_svelte_file(self, language_server: SolidLanguageServer) -> None:
         file_path = os.path.join("src", "lib", "components", "Header.svelte")
         coords = find_text_coordinates(read_repo_file(language_server, file_path), r"(count)")
+        assert coords is not None
 
         definitions = language_server.request_definition(file_path, coords.line, coords.col)
-        definition_paths = sorted(definition["relativePath"].replace("\\", "/") for definition in definitions)
+        definition_paths = sorted(definition["relativePath"].replace("\\", "/") for definition in definitions)  # type: ignore
 
         assert len(definitions) == 1, definition_paths
-        assert definitions[0]["relativePath"].replace("\\", "/") == "src/lib/components/Counter.svelte", definition_paths
+        assert definitions[0]["relativePath"].replace("\\", "/") == "src/lib/components/Counter.svelte", definition_paths  # type: ignore
 
     @pytest.mark.parametrize("language_server", [LanguageServerId.SVELTE], indirect=True)
     def test_diagnostics_in_typescript_file(self, language_server: SolidLanguageServer) -> None:

test/solidlsp/svelte/test_svelte_references.py

@@ -12,7 +12,7 @@ class TestSvelteReferences:
     @pytest.mark.parametrize("language_server", [LanguageServerId.SVELTE], indirect=True)
     def test_references_across_svelte_and_typescript(self, language_server: SolidLanguageServer) -> None:
         refs = language_server.request_references(os.path.join("src", "lib", "components", "Words.svelte"), 1, 17)
-        ref_paths = {ref["relativePath"].replace("\\", "/") for ref in refs}
+        ref_paths = {ref["relativePath"].replace("\\", "/") for ref in refs}  # type: ignore
 
         assert "src/routes/(sverdle)/words.server.ts" in ref_paths, sorted(ref_paths)
         assert "src/lib/game.ts" in ref_paths, sorted(ref_paths)
@@ -21,6 +21,6 @@ class TestSvelteReferences:
     @pytest.mark.parametrize("language_server", [LanguageServerId.SVELTE], indirect=True)
     def test_references_from_typescript_file(self, language_server: SolidLanguageServer) -> None:
         refs = language_server.request_references(os.path.join("src", "lib", "game.ts"), 3, 13)
-        ref_paths = {ref["relativePath"].replace("\\", "/") for ref in refs}
+        ref_paths = {ref["relativePath"].replace("\\", "/") for ref in refs}  # type: ignore
 
         assert "src/routes/(sverdle)/+page.server.ts" in ref_paths, sorted(ref_paths)

test/solidlsp/svelte/test_svelte_rename.py

@@ -56,6 +56,7 @@ class TestSvelteRename:
     def test_rename_svelte_export_updates_svelte_importers(self, language_server: SolidLanguageServer) -> None:
         file_path = os.path.join("src", "lib", "components", "Counter.svelte")
         coords = find_text_coordinates(read_repo_file(language_server, file_path), r"(count)")
+        assert coords is not None
 
         workspace_edit = language_server.request_rename_symbol_edit(file_path, coords.line, coords.col, "score")
 
@@ -69,6 +70,7 @@ class TestSvelteRename:
     def test_rename_svelte_export_updates_ts_and_svelte_files(self, language_server: SolidLanguageServer) -> None:
         file_path = os.path.join("src", "lib", "components", "Words.svelte")
         coords = find_text_coordinates(read_repo_file(language_server, file_path), r"(words)")
+        assert coords is not None
 
         workspace_edit = language_server.request_rename_symbol_edit(file_path, coords.line, coords.col, "vocabulary")
 

test/solidlsp/test_ls_start_cleanup.py

@@ -38,7 +38,7 @@ def test_start_stops_process_when_start_server_raises_after_spawning():
     with pytest.raises(RuntimeError, match="capability assertion"):
         server.start()
 
-    server.server.stop.assert_called_once()
+    server.server.stop.assert_called_once()  # type: ignore
     assert server.server_started is False
 
 
@@ -51,5 +51,5 @@ def test_start_does_not_call_stop_when_start_server_raises_before_spawning():
     with pytest.raises(RuntimeError, match="capability assertion"):
         server.start()
 
-    server.server.stop.assert_not_called()
+    server.server.stop.assert_not_called()  # type: ignore
     assert server.server_started is False

test/solidlsp/test_pdeathsig.py

@@ -115,8 +115,8 @@ def test_language_server_process_survives_a_short_lived_calling_thread() -> None
         text=True,
     )
     try:
-        ready_line = driver.stdout.readline()
-        assert ready_line.strip() == "READY", f"driver failed to start the language server: {driver.stderr.read()}"
+        ready_line = driver.stdout.readline()  # type: ignore
+        assert ready_line.strip() == "READY", f"driver failed to start the language server: {driver.stderr.read()}"  # type: ignore
 
         time.sleep(2)
         # The driver's own argv also contains `marker` (it's passed as sys.argv[1]), so exclude
@@ -143,8 +143,10 @@ def test_language_server_process_dies_with_a_sigkilled_serena() -> None:
         text=True,
     )
     try:
-        ready_line = driver.stdout.readline()
-        assert ready_line.strip() == "READY", f"driver failed to start the language server: {driver.stderr.read()}"
+        ready_line = driver.stdout.readline()  # type: ignore
+        stderr = driver.stderr
+        assert stderr is not None, "stderr should be captured"
+        assert ready_line.strip() == "READY", f"driver failed to start the language server: {stderr.read()}"
         assert _find_marked_processes(marker), "language server process never started"
 
         driver.kill()  # SIGKILL: simulates Serena being killed without a chance to clean up

test/solidlsp/test_process_group_cleanup.py

@@ -80,7 +80,9 @@ def _spawn_ready(src: str) -> subprocess.Popen:
     test_pdeathsig.py's driver pattern (deterministic sync instead of a blind sleep).
     """
     proc = subprocess.Popen([sys.executable, "-c", src], start_new_session=True, stdout=subprocess.PIPE, text=True)
-    ready_line = proc.stdout.readline()
+    stdout = proc.stdout
+    assert stdout is not None
+    ready_line = stdout.readline()
     assert ready_line.strip() == "READY", f"helper process failed to start: {ready_line!r}"
     return proc
 
@@ -341,8 +343,10 @@ class TestPsutilDenialConsequences:
             """
         )
         proc = subprocess.Popen([sys.executable, "-c", src], start_new_session=True, stdout=subprocess.PIPE, text=True)
-        child_pid = int(proc.stdout.readline().strip())
-        ready_line = proc.stdout.readline()
+        stdout = proc.stdout
+        assert stdout is not None
+        child_pid = int(stdout.readline().strip())
+        ready_line = stdout.readline()
         assert ready_line.strip() == "READY", f"helper process failed to start: {ready_line!r}"
         return proc, child_pid