Split model call and tool loop helpers

test/model-call-stage.test.mjs

@@ -0,0 +1,17 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const {runSingleModelRequest} = await import("../dist/ai/model-call-stage.js");
+
+test("single model request wrapper executes exactly once", async () => {
+    let calls = 0;
+    const result = await runSingleModelRequest({
+        async execute() {
+            calls += 1;
+            return "ok";
+        },
+    });
+
+    assert.equal(result, "ok");
+    assert.equal(calls, 1);
+});

test/tool-loop-runner.test.mjs

@@ -0,0 +1,37 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const {runToolLoopRounds} = await import("../dist/ai/tool-loop-runner.js");
+
+test("tool loop runner stops when handler requests it", async () => {
+    const rounds = [];
+
+    await runToolLoopRounds({
+        maxRounds: 5,
+        async onRound(round) {
+            rounds.push(round);
+            return {shouldContinue: round < 1};
+        },
+    });
+
+    assert.deepEqual(rounds, [0, 1]);
+});
+
+test("tool loop runner calls max rounds hook when handler never stops", async () => {
+    const rounds = [];
+    let maxRoundsReached = -1;
+
+    await runToolLoopRounds({
+        maxRounds: 3,
+        async onRound(round) {
+            rounds.push(round);
+            return {shouldContinue: true};
+        },
+        onMaxRoundsReached(round) {
+            maxRoundsReached = round;
+        },
+    });
+
+    assert.deepEqual(rounds, [0, 1, 2]);
+    assert.equal(maxRoundsReached, 2);
+});