tooling: supply anchored previous question in update-only mode

scripts/reproduce-multi-turn-investigation.mjs

@@ -239,7 +239,10 @@ async function runUpdateOnlyMode() {
 
   // Deep-copy so mutation doesn't corrupt the original fixture.
   const situationGraph = JSON.parse(JSON.stringify(initialGraph));
-  let selectedQuestion = null;
+
+  // Derive previousQuestion from the committed savings-realism anchor so that
+  // update-only mode can reach the production Update path without requiring Start.
+  let selectedQuestion = fixtureData.unresolved_question ?? savingsNode.label;
 
   // ── Exactly one Update through production route ────────
   const updateNum = 1;

tests/reproduce-multi-turn-investigation.harness.test.js

@@ -651,15 +651,53 @@ describe("reproduce-multi-turn-investigation harness: one-shot semantics", () =>
     expect(r.startCalls).toBe(0);
     expect(r.updateCalls).toBe(1);
 
+    // Direct assertion: exact fixture graph transmitted (57J.81)
+    const updateBody = r.capturedUpdateBody;
+    expect(updateBody.situationGraph).toBeDefined();
+    const fixtureGraph = PRE_ANCHORED_FIXTURE.graph;
+    expect(JSON.parse(JSON.stringify(updateBody.situationGraph.nodes))).toEqual(fixtureGraph.nodes);
+    expect(JSON.parse(JSON.stringify(updateBody.situationGraph.edges))).toEqual(fixtureGraph.edges);
+
     // Verify the captured graph matches what was sent
     const { nodes, edges } = r;
-    const fixtureGraph = PRE_ANCHORED_FIXTURE.graph;
     expect(nodes.length).toBe(fixtureGraph.nodes.length);
     expect(edges.length).toBe(fixtureGraph.edges.length);
     expect(nodes[0].id).toBe(fixtureGraph.nodes[0].id);
     expect(nodes[1].id).toBe(fixtureGraph.nodes[1].id);
   });
 
+  it("57J.81 update-only previousQuestion is non-empty string and matches the committed savings-realism anchor", () => {
+    const r = runPreAnchoredSimulation();
+    expect(r.startCalls).toBe(0);
+    expect(r.updateCalls).toBe(1);
+
+    const prevQ = r.capturedUpdateBody.previousQuestion;
+    expect(typeof prevQ).toBe("string");
+    expect(prevQ.length).toBeGreaterThan(0);
+    // Must correspond exactly to the anchored savings-realism uncertainty
+    expect(prevQ).toBe(PRE_ANCHORED_FIXTURE.unresolvedQuestion);
+    expect(prevQ).toBe("Are the projected office savings from relocation realistic?");
+  });
+
+  it("57J.81 update-only exact ANSWER_2 sent as request answer", () => {
+    const customAnswer = "The projected savings are based on the current London lease and business rates.";
+    const r = runPreAnchoredSimulation({ answer: customAnswer });
+    expect(r.startCalls).toBe(0);
+    expect(r.updateCalls).toBe(1);
+
+    // Direct assertion of exact ANSWER_2 in request body
+    expect(r.capturedUpdateBody.answer).toBe(customAnswer);
+  });
+
+  it("57J.81 missing ANSWER_2 blocks before any HTTP call", () => {
+    const r = runPreAnchoredSimulationWithBlock();
+    expect(r.startCalls).toBe(0);
+    expect(r.updateCalls).toBe(0);
+    expect(r.type).toBe("blocked_no_answer");
+    expect(r.blockedMessage).toContain("missing ANSWER_2");
+    expect(r.apiLog.length).toBe(0);
+  });
+
   it("pre-anchored update-only mode does not call Start", () => {
     const r = runPreAnchoredSimulation();
     expect(r.startCalls).toBe(0);
@@ -1061,7 +1099,14 @@ function runPreAnchoredSimulation(cfg) {
 
   // Pre-anchored: no Start call — graph is supplied directly.
   let graph = JSON.parse(JSON.stringify(initialGraph));
-  let question = null; // will be set by the update response (or mock)
+
+  // Derive previousQuestion from the committed savings-realism anchor
+  // (mirrors the harness fix in reproduce-multi-turn-investigation.mjs).
+  const unresolvedQuestion = PRE_ANCHORED_FIXTURE.unresolvedQuestion;
+  let question = unresolvedQuestion; // fixture always has this field for pre-anchored mode
+
+  // Track the exact Update request body for direct assertions.
+  let capturedUpdateBody = null;
 
   const api = {
     post(path, body) {
@@ -1073,6 +1118,7 @@ function runPreAnchoredSimulation(cfg) {
 
       if (path === "/api/cases/update") {
         apiLog.push({ step: "update", answer: body.answer });
+        capturedUpdateBody = body; // capture for direct request-body assertions
         updateCalls++;
 
         const resp = typeof C.onResponseUpdate === "function"
@@ -1161,6 +1207,7 @@ function runPreAnchoredSimulation(cfg) {
       selectedQuestion: sq && typeof sq === "object" ? { question: sq.question, nodeId: sq.nodeId } : null,
       graph: { nodes: uj.updatedSituationGraph?.nodes ?? [], edges: uj.updatedSituationGraph?.edges ?? [] },
     },
+    capturedUpdateBody,
   };
 }