Function TestSchemaForMessage_CycleSafe

internal/mcp/schema_test.go:50–61

TestSchemaForMessage_CycleSafe — google.protobuf.Value references itself via repeated Value (ListValue.values). Before the cycle-guard fix, exposing any tool whose request includes a Struct or Value field would stack-overflow at boot. The visited-set short-circuits and emits an opaque `object`.

(t *testing.T)

// any tool whose request includes a Struct or Value field would stack-overflow
// at boot. The visited-set short-circuits and emits an opaque `object`.
func TestSchemaForMessage_CycleSafe(t *testing.T) {
	// AppData wraps google.protobuf.Struct, which contains a
	// map<string, Value>, where Value can hold a ListValue of more Values.
	// That's the exact recursion that would stack-overflow without the guard.
	app := (&authorizerv1.SignupRequest{}).ProtoReflect().Descriptor().Fields().ByName("app_data")
	require.NotNil(t, app)

	schema := schemaForField(app, map[protoreflect.FullName]struct{}{})
	// Doesn't panic / overflow. The deeply-nested Value type collapses to
	// an opaque object once the cycle is detected.
	assert.Equal(t, "object", schema.Type)
}

// TestSchemaForMessage_ScalarOnly walks a request that's purely scalars
// (no nested message). Profile takes no arguments at all; Session takes