Add test for completions capability exposition by server

Author: fredericbarthelet

tests/server/test_session.py

@@ -11,6 +11,7 @@
 from mcp.shared.session import RequestResponder
 from mcp.types import (
     ClientNotification,
+    CompletionsCapability,
     InitializedNotification,
     PromptsCapability,
     ResourcesCapability,
@@ -88,6 +89,7 @@ async def test_server_capabilities():
     caps = server.get_capabilities(notification_options, experimental_capabilities)
     assert caps.prompts is None
     assert caps.resources is None
+    assert caps.completions is None
 
     # Add a prompts handler
     @server.list_prompts()
@@ -97,6 +99,7 @@ async def list_prompts():
     caps = server.get_capabilities(notification_options, experimental_capabilities)
     assert caps.prompts == PromptsCapability(listChanged=False)
     assert caps.resources is None
+    assert caps.completions is None
 
     # Add a resources handler
     @server.list_resources()
@@ -106,6 +109,17 @@ async def list_resources():
     caps = server.get_capabilities(notification_options, experimental_capabilities)
     assert caps.prompts == PromptsCapability(listChanged=False)
     assert caps.resources == ResourcesCapability(subscribe=False, listChanged=False)
+    assert caps.completions is None
+
+    # Add a complete handler
+    @server.completion()
+    async def complete():
+        return None
+
+    caps = server.get_capabilities(notification_options, experimental_capabilities)
+    assert caps.prompts == PromptsCapability(listChanged=False)
+    assert caps.resources == ResourcesCapability(subscribe=False, listChanged=False)
+    assert caps.completions == CompletionsCapability()
 
 
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