SEP-1686: Tasks (#1645)

tests/server/test_validation.py

@@ -0,0 +1,141 @@
+"""Tests for server validation functions."""
+
+import pytest
+
+from mcp.server.validation import (
+    check_sampling_tools_capability,
+    validate_sampling_tools,
+    validate_tool_use_result_messages,
+)
+from mcp.shared.exceptions import McpError
+from mcp.types import (
+    ClientCapabilities,
+    SamplingCapability,
+    SamplingMessage,
+    SamplingToolsCapability,
+    TextContent,
+    Tool,
+    ToolChoice,
+    ToolResultContent,
+    ToolUseContent,
+)
+
+
+class TestCheckSamplingToolsCapability:
+    """Tests for check_sampling_tools_capability function."""
+
+    def test_returns_false_when_caps_none(self) -> None:
+        """Returns False when client_caps is None."""
+        assert check_sampling_tools_capability(None) is False
+
+    def test_returns_false_when_sampling_none(self) -> None:
+        """Returns False when client_caps.sampling is None."""
+        caps = ClientCapabilities()
+        assert check_sampling_tools_capability(caps) is False
+
+    def test_returns_false_when_tools_none(self) -> None:
+        """Returns False when client_caps.sampling.tools is None."""
+        caps = ClientCapabilities(sampling=SamplingCapability())
+        assert check_sampling_tools_capability(caps) is False
+
+    def test_returns_true_when_tools_present(self) -> None:
+        """Returns True when sampling.tools is present."""
+        caps = ClientCapabilities(sampling=SamplingCapability(tools=SamplingToolsCapability()))
+        assert check_sampling_tools_capability(caps) is True
+
+
+class TestValidateSamplingTools:
+    """Tests for validate_sampling_tools function."""
+
+    def test_no_error_when_tools_none(self) -> None:
+        """No error when tools and tool_choice are None."""
+        validate_sampling_tools(None, None, None)  # Should not raise
+
+    def test_raises_when_tools_provided_but_no_capability(self) -> None:
+        """Raises McpError when tools provided but client doesn't support."""
+        tool = Tool(name="test", inputSchema={"type": "object"})
+        with pytest.raises(McpError) as exc_info:
+            validate_sampling_tools(None, [tool], None)
+        assert "sampling tools capability" in str(exc_info.value)
+
+    def test_raises_when_tool_choice_provided_but_no_capability(self) -> None:
+        """Raises McpError when tool_choice provided but client doesn't support."""
+        with pytest.raises(McpError) as exc_info:
+            validate_sampling_tools(None, None, ToolChoice(mode="auto"))
+        assert "sampling tools capability" in str(exc_info.value)
+
+    def test_no_error_when_capability_present(self) -> None:
+        """No error when client has sampling.tools capability."""
+        caps = ClientCapabilities(sampling=SamplingCapability(tools=SamplingToolsCapability()))
+        tool = Tool(name="test", inputSchema={"type": "object"})
+        validate_sampling_tools(caps, [tool], ToolChoice(mode="auto"))  # Should not raise
+
+
+class TestValidateToolUseResultMessages:
+    """Tests for validate_tool_use_result_messages function."""
+
+    def test_no_error_for_empty_messages(self) -> None:
+        """No error when messages list is empty."""
+        validate_tool_use_result_messages([])  # Should not raise
+
+    def test_no_error_for_simple_text_messages(self) -> None:
+        """No error for simple text messages."""
+        messages = [
+            SamplingMessage(role="user", content=TextContent(type="text", text="Hello")),
+            SamplingMessage(role="assistant", content=TextContent(type="text", text="Hi")),
+        ]
+        validate_tool_use_result_messages(messages)  # Should not raise
+
+    def test_raises_when_tool_result_mixed_with_other_content(self) -> None:
+        """Raises when tool_result is mixed with other content types."""
+        messages = [
+            SamplingMessage(
+                role="user",
+                content=[
+                    ToolResultContent(type="tool_result", toolUseId="123"),
+                    TextContent(type="text", text="also this"),
+                ],
+            ),
+        ]
+        with pytest.raises(ValueError, match="only tool_result content"):
+            validate_tool_use_result_messages(messages)
+
+    def test_raises_when_tool_result_without_previous_tool_use(self) -> None:
+        """Raises when tool_result appears without preceding tool_use."""
+        messages = [
+            SamplingMessage(
+                role="user",
+                content=ToolResultContent(type="tool_result", toolUseId="123"),
+            ),
+        ]
+        with pytest.raises(ValueError, match="previous message containing tool_use"):
+            validate_tool_use_result_messages(messages)
+
+    def test_raises_when_tool_result_ids_dont_match_tool_use(self) -> None:
+        """Raises when tool_result IDs don't match tool_use IDs."""
+        messages = [
+            SamplingMessage(
+                role="assistant",
+                content=ToolUseContent(type="tool_use", id="tool-1", name="test", input={}),
+            ),
+            SamplingMessage(
+                role="user",
+                content=ToolResultContent(type="tool_result", toolUseId="tool-2"),
+            ),
+        ]
+        with pytest.raises(ValueError, match="do not match"):
+            validate_tool_use_result_messages(messages)
+
+    def test_no_error_when_tool_result_matches_tool_use(self) -> None:
+        """No error when tool_result IDs match tool_use IDs."""
+        messages = [
+            SamplingMessage(
+                role="assistant",
+                content=ToolUseContent(type="tool_use", id="tool-1", name="test", input={}),
+            ),
+            SamplingMessage(
+                role="user",
+                content=ToolResultContent(type="tool_result", toolUseId="tool-1"),
+            ),
+        ]
+        validate_tool_use_result_messages(messages)  # Should not raise