diff --git a/api/tests/unit_tests/core/app/apps/test_exc.py b/api/tests/unit_tests/core/app/apps/test_exc.py
index e41c78e89e3..4a35313fa6d 100644
--- a/api/tests/unit_tests/core/app/apps/test_exc.py
+++ b/api/tests/unit_tests/core/app/apps/test_exc.py
@@ -2,6 +2,6 @@ from core.app.apps.exc import GenerateTaskStoppedError
 
 
 class TestAppsExceptions:
-    def test_generate_task_stopped_error(self):
+    def test_generate_task_stopped_error(self) -> None:
         err = GenerateTaskStoppedError("stopped")
         assert str(err) == "stopped"
diff --git a/api/tests/unit_tests/core/app/apps/workflow/test_errors.py b/api/tests/unit_tests/core/app/apps/workflow/test_errors.py
index 7461e068332..59b5303255c 100644
--- a/api/tests/unit_tests/core/app/apps/workflow/test_errors.py
+++ b/api/tests/unit_tests/core/app/apps/workflow/test_errors.py
@@ -2,8 +2,9 @@ from core.app.apps.workflow.errors import WorkflowPausedInBlockingModeError
 
 
 class TestWorkflowErrors:
-    def test_workflow_paused_in_blocking_mode_error_attributes(self):
+    def test_workflow_paused_in_blocking_mode_error_attributes(self) -> None:
         err = WorkflowPausedInBlockingModeError()
         assert err.error_code == "workflow_paused_in_blocking_mode"
         assert err.code == 400
+        assert err.description is not None
         assert "blocking response mode" in err.description
diff --git a/api/tests/unit_tests/core/app/task_pipeline/test_exc.py b/api/tests/unit_tests/core/app/task_pipeline/test_exc.py
index 9ea7e96e73d..dbeeff8655b 100644
--- a/api/tests/unit_tests/core/app/task_pipeline/test_exc.py
+++ b/api/tests/unit_tests/core/app/task_pipeline/test_exc.py
@@ -2,10 +2,10 @@ from core.app.task_pipeline.exc import RecordNotFoundError, WorkflowRunNotFoundE
 
 
 class TestTaskPipelineExceptions:
-    def test_record_not_found_error_message(self):
+    def test_record_not_found_error_message(self) -> None:
         err = RecordNotFoundError("Message", "msg-1")
         assert str(err) == "Message with id msg-1 not found"
 
-    def test_workflow_run_not_found_error_message(self):
+    def test_workflow_run_not_found_error_message(self) -> None:
         err = WorkflowRunNotFoundError("run-1")
         assert str(err) == "WorkflowRun with id run-1 not found"
diff --git a/api/tests/unit_tests/core/plugin/impl/test_debugging.py b/api/tests/unit_tests/core/plugin/impl/test_debugging.py
index 05959207b1a..4a747c77ad2 100644
--- a/api/tests/unit_tests/core/plugin/impl/test_debugging.py
+++ b/api/tests/unit_tests/core/plugin/impl/test_debugging.py
@@ -6,7 +6,7 @@ from core.plugin.impl.debugging import PluginDebuggingClient
 
 
 class TestPluginDebuggingClient:
-    def test_get_debugging_key(self, mocker: MockerFixture):
+    def test_get_debugging_key(self, mocker: MockerFixture) -> None:
         client = PluginDebuggingClient()
         request_mock = mocker.patch.object(
             client,
diff --git a/api/tests/unit_tests/core/rag/extractor/test_html_extractor.py b/api/tests/unit_tests/core/rag/extractor/test_html_extractor.py
index c1c675e0d45..3437351c8dd 100644
--- a/api/tests/unit_tests/core/rag/extractor/test_html_extractor.py
+++ b/api/tests/unit_tests/core/rag/extractor/test_html_extractor.py
@@ -4,7 +4,7 @@ from core.rag.extractor.html_extractor import HtmlExtractor
 
 
 class TestHtmlExtractor:
-    def test_extract_returns_text_content(self, tmp_path: Path):
+    def test_extract_returns_text_content(self, tmp_path: Path) -> None:
         file_path = tmp_path / "sample.html"
         file_path.write_text("<html><body><h1>Title</h1><p>Hello</p></body></html>", encoding="utf-8")
 
@@ -14,7 +14,7 @@ class TestHtmlExtractor:
         assert len(docs) == 1
         assert "".join(docs[0].page_content.split()) == "TitleHello"
 
-    def test_load_as_text_strips_whitespace_and_handles_empty(self, tmp_path: Path):
+    def test_load_as_text_strips_whitespace_and_handles_empty(self, tmp_path: Path) -> None:
         file_path = tmp_path / "sample.html"
         file_path.write_text("<html><body>   \n  </body></html>", encoding="utf-8")
 
diff --git a/api/tests/unit_tests/core/trigger/utils/test_endpoint.py b/api/tests/unit_tests/core/trigger/utils/test_endpoint.py
index e5879aea0a0..e90295335a5 100644
--- a/api/tests/unit_tests/core/trigger/utils/test_endpoint.py
+++ b/api/tests/unit_tests/core/trigger/utils/test_endpoint.py
@@ -10,7 +10,7 @@ from core.trigger.utils import endpoint
 
 
 class TestGeneratePluginTriggerEndpointUrl:
-    def test_builds_correct_url(self):
+    def test_builds_correct_url(self) -> None:
         with patch.object(endpoint, "base_url", URL("https://api.example.com")):
             url = endpoint.generate_plugin_trigger_endpoint_url("endpoint-123")
 
@@ -18,13 +18,13 @@ class TestGeneratePluginTriggerEndpointUrl:
 
 
 class TestGenerateWebhookTriggerEndpoint:
-    def test_non_debug_url(self):
+    def test_non_debug_url(self) -> None:
         with patch.object(endpoint, "base_url", URL("https://api.example.com")):
             url = endpoint.generate_webhook_trigger_endpoint("sub-456", debug=False)
 
         assert url == "https://api.example.com/triggers/webhook/sub-456"
 
-    def test_debug_url(self):
+    def test_debug_url(self) -> None:
         with patch.object(endpoint, "base_url", URL("https://api.example.com")):
             url = endpoint.generate_webhook_trigger_endpoint("sub-456", debug=True)
 
diff --git a/api/tests/unit_tests/core/trigger/utils/test_locks.py b/api/tests/unit_tests/core/trigger/utils/test_locks.py
index 4fa202b1647..c4a0e6f5109 100644
--- a/api/tests/unit_tests/core/trigger/utils/test_locks.py
+++ b/api/tests/unit_tests/core/trigger/utils/test_locks.py
@@ -2,18 +2,21 @@
 
 from __future__ import annotations
 
-from core.trigger.utils.locks import build_trigger_refresh_lock_key, build_trigger_refresh_lock_keys
+from core.trigger.utils.locks import (
+    build_trigger_refresh_lock_key,
+    build_trigger_refresh_lock_keys,
+)
 
 
 class TestBuildTriggerRefreshLockKey:
-    def test_correct_format(self):
+    def test_correct_format(self) -> None:
         key = build_trigger_refresh_lock_key("tenant-1", "sub-1")
 
         assert key == "trigger_provider_refresh_lock:tenant-1_sub-1"
 
 
 class TestBuildTriggerRefreshLockKeys:
-    def test_maps_over_pairs(self):
+    def test_maps_over_pairs(self) -> None:
         pairs = [("t1", "s1"), ("t2", "s2")]
 
         keys = build_trigger_refresh_lock_keys(pairs)
diff --git a/api/tests/unit_tests/libs/test_orjson.py b/api/tests/unit_tests/libs/test_orjson.py
index 6df1d077df7..e5df20708cf 100644
--- a/api/tests/unit_tests/libs/test_orjson.py
+++ b/api/tests/unit_tests/libs/test_orjson.py
@@ -4,13 +4,13 @@ import pytest
 from libs.orjson import orjson_dumps
 
 
-def test_orjson_dumps_round_trip_basic():
+def test_orjson_dumps_round_trip_basic() -> None:
     obj = {"a": 1, "b": [1, 2, 3], "c": {"d": True}}
     s = orjson_dumps(obj)
     assert orjson.loads(s) == obj
 
 
-def test_orjson_dumps_with_unicode_and_indent():
+def test_orjson_dumps_with_unicode_and_indent() -> None:
     obj = {"msg": "你好，Dify"}
     s = orjson_dumps(obj, option=orjson.OPT_INDENT_2)
     # contains indentation newline/spaces
@@ -18,7 +18,7 @@ def test_orjson_dumps_with_unicode_and_indent():
     assert orjson.loads(s) == obj
 
 
-def test_orjson_dumps_non_utf8_encoding_fails():
+def test_orjson_dumps_non_utf8_encoding_fails() -> None:
     obj = {"msg": "你好"}
     # orjson.dumps() always produces UTF-8 bytes; decoding with non-UTF8 fails.
     with pytest.raises(UnicodeDecodeError):
diff --git a/api/tests/unit_tests/pyrefly.toml b/api/tests/unit_tests/pyrefly.toml
index f2af3fdc2b9..e662dc5b691 100644
--- a/api/tests/unit_tests/pyrefly.toml
+++ b/api/tests/unit_tests/pyrefly.toml
@@ -171,7 +171,6 @@ project-excludes = [
   "core/app/apps/pipeline/test_pipeline_runner.py",
   "core/app/apps/test_base_app_generator.py",
   "core/app/apps/test_base_app_queue_manager.py",
-  "core/app/apps/test_exc.py",
   "core/app/apps/test_message_based_app_generator.py",
   "core/app/apps/test_message_generator.py",
   "core/app/apps/test_streaming_utils.py",
@@ -182,7 +181,6 @@ project-excludes = [
   "core/app/apps/workflow/test_app_config_manager.py",
   "core/app/apps/workflow/test_app_queue_manager.py",
   "core/app/apps/workflow/test_command_channels.py",
-  "core/app/apps/workflow/test_errors.py",
   "core/app/apps/workflow/test_generate_response_converter.py",
   "core/app/apps/workflow/test_generate_task_pipeline.py",
   "core/app/entities/test_app_invoke_entities.py",
@@ -195,7 +193,6 @@ project-excludes = [
   "core/app/layers/test_trigger_post_layer.py",
   "core/app/task_pipeline/test_based_generate_task_pipeline.py",
   "core/app/task_pipeline/test_easy_ui_based_generate_task_pipeline.py",
-  "core/app/task_pipeline/test_exc.py",
   "core/app/task_pipeline/test_message_cycle_manager.py",
   "core/app/app_config/easy_ui_based_app/model_config/test_manager.py",
   "core/app/llm/test_quota.py",
@@ -237,7 +234,6 @@ project-excludes = [
   "core/plugin/impl/test_asset.py",
   "core/plugin/impl/test_base.py",
   "core/plugin/impl/test_datasource.py",
-  "core/plugin/impl/test_debugging.py",
   "core/plugin/impl/test_endpoint.py",
   "core/plugin/impl/test_exc.py",
   "core/plugin/impl/test_model.py",
@@ -262,7 +258,6 @@ project-excludes = [
   "core/rag/extractor/test_excel_extractor.py",
   "core/rag/extractor/test_extract_processor.py",
   "core/rag/extractor/test_helpers.py",
-  "core/rag/extractor/test_html_extractor.py",
   "core/rag/extractor/test_markdown_extractor.py",
   "core/rag/extractor/test_word_extractor.py",
   "core/rag/extractor/watercrawl/test_client.py",
@@ -306,8 +301,6 @@ project-excludes = [
   "core/tools/workflow_as_tool/test_provider.py",
   "core/tools/workflow_as_tool/test_tool.py",
   "core/trigger/utils/test_encryption.py",
-  "core/trigger/utils/test_endpoint.py",
-  "core/trigger/utils/test_locks.py",
   "context/test_execution_context.py",
   "context/test_flask_app_context.py",
   "../e2e_tests/contracts/core/workflow/entities/test_private_workflow_pause.py",
@@ -398,7 +391,6 @@ project-excludes = [
   "libs/test_flask_utils.py",
   "libs/test_helper.py",
   "libs/test_login.py",
-  "libs/test_orjson.py",
   "../e2e_tests/contracts/libs/test_pandas.py",
   "libs/test_token.py",
   "migrations/versions/test_2025_07_02_2332-1c9ba48be8e4_add_uuidv7_function_in_sql.py",
@@ -480,7 +472,6 @@ project-excludes = [
   "services/tools/test_api_tools_manage_service.py",
   "services/tools/test_builtin_tools_manage_service.py",
   "services/tools/test_tools_transform_service.py",
-  "services/tools/test_tool_labels_service.py",
   "services/tools/test_tools_manage_service.py",
   "services/test_workflow_draft_variable_service.py",
   "services/workflow/test_node_output_inspector_service.py",
diff --git a/api/tests/unit_tests/services/tools/test_tool_labels_service.py b/api/tests/unit_tests/services/tools/test_tool_labels_service.py
index 6acdbb79019..504169b22a5 100644
--- a/api/tests/unit_tests/services/tools/test_tool_labels_service.py
+++ b/api/tests/unit_tests/services/tools/test_tool_labels_service.py
@@ -1,13 +1,13 @@
 from services.tools.tool_labels_service import ToolLabelsService
 
 
-def test_list_tool_labels_returns_default_labels():
+def test_list_tool_labels_returns_default_labels() -> None:
     result = ToolLabelsService.list_tool_labels()
     assert isinstance(result, list)
     assert len(result) > 0
 
 
-def test_list_tool_labels_items_are_tool_labels():
+def test_list_tool_labels_items_are_tool_labels() -> None:
     from core.tools.entities.tool_entities import ToolLabel
 
     result = ToolLabelsService.list_tool_labels()
@@ -15,7 +15,7 @@ def test_list_tool_labels_items_are_tool_labels():
         assert isinstance(label, ToolLabel)
 
 
-def test_list_tool_labels_matches_default_values():
+def test_list_tool_labels_matches_default_values() -> None:
     from core.tools.entities.values import default_tool_labels
 
     assert ToolLabelsService.list_tool_labels() is default_tool_labels