Add deterministic agent protocol harness (#133)

crates/metacrate-grid-agent/tests/policy_gateway.rs

@@ -1,16 +1,16 @@
 use libremetaverse_types::UUID;
 use libremetaverse_types::compat::CancellationToken;
+use metacrate_grid_agent::testing::FakeGrid;
 use metacrate_grid_agent::{
-    ActionOrigin, AllowedOrigins, AuthorizedAction, AuthorizedToolBackend, BackendError,
-    BackendFuture, BoundedText, Capability, FixedCost, Idempotency, MemoryPolicyAudit, OriginClass,
-    PolicyAuditSink, PolicyDisposition, PolicyFinalOutcome, PolicyGateway, PolicyLimits,
-    PolicyRequestContext, PolicyTool, PolicyToolExecutor, ProposedToolCall, ResourceCost, Risk,
-    ToolCallOutcome, ToolDefinition, ToolExecution, ToolExecutor, ToolSchema,
+    ActionOrigin, AllowedOrigins, AuthorizedToolBackend, BoundedText, Capability, FixedCost,
+    Idempotency, MemoryPolicyAudit, OriginClass, PolicyAuditSink, PolicyDisposition,
+    PolicyFinalOutcome, PolicyGateway, PolicyLimits, PolicyRequestContext, PolicyTool,
+    PolicyToolExecutor, ProposedToolCall, ResourceCost, Risk, ToolDefinition, ToolExecution,
+    ToolExecutor, ToolSchema,
 };
 use serde_json::{Value, json};
 use std::collections::{BTreeMap, BTreeSet};
 use std::sync::Arc;
-use std::sync::atomic::{AtomicUsize, Ordering};
 
 fn id(text: &str) -> UUID {
     UUID::new_with_string(text.to_owned()).expect("fixture UUID")
@@ -88,25 +88,6 @@ fn call(name: &str) -> (ProposedToolCall, Value) {
     )
 }
 
-struct RecordingBackend(AtomicUsize);
-
-impl AuthorizedToolBackend for RecordingBackend {
-    fn apply(
-        &self,
-        action: AuthorizedAction,
-        _cancellation: CancellationToken,
-    ) -> BackendFuture<'_, Result<ToolCallOutcome, BackendError>> {
-        self.0.fetch_add(1, Ordering::AcqRel);
-        let call_id = action.call().call_id.clone();
-        Box::pin(async move {
-            Ok(ToolCallOutcome::Completed {
-                call_id,
-                result: BoundedText::new("result", "moved").expect("result"),
-            })
-        })
-    }
-}
-
 #[tokio::test]
 async fn production_executor_denies_public_mutation_and_executes_authorized_im_once() {
     let authorized = id("11111111-1111-4111-8111-111111111111");
@@ -121,8 +102,8 @@ async fn production_executor_denies_public_mutation_and_executes_authorized_im_o
         )
         .expect("gateway"),
     );
-    let backend = Arc::new(RecordingBackend(AtomicUsize::new(0)));
-    let erased: Arc<dyn AuthorizedToolBackend> = backend.clone();
+    let backend = FakeGrid::scripted([]);
+    let erased: Arc<dyn AuthorizedToolBackend> = Arc::new(backend.clone());
     let (proposed, arguments) = call("move");
     let definition = gateway
         .tools_for(
@@ -162,7 +143,7 @@ async fn production_executor_denies_public_mutation_and_executes_authorized_im_o
             .await,
         ToolExecution::Rejected(_)
     ));
-    assert_eq!(backend.0.load(Ordering::Acquire), 0);
+    assert!(backend.evidence().is_empty());
 
     let authorized_executor = PolicyToolExecutor::new(
         gateway,
@@ -188,7 +169,10 @@ async fn production_executor_denies_public_mutation_and_executes_authorized_im_o
             .await,
         ToolExecution::Completed(_)
     ));
-    assert_eq!(backend.0.load(Ordering::Acquire), 1);
+    let evidence = backend.evidence();
+    assert_eq!(evidence.len(), 1);
+    assert_eq!(evidence[0].operation, "policy.route.move");
+    assert_eq!(evidence[0].outcome, "authorized");
     assert_eq!(
         audit.snapshot().last().expect("outcome").final_outcome,
         PolicyFinalOutcome::Completed