fix(api): map persisted combo steps in the playground route simulator

changelog.d/fixes/11882-simulate-route-combo-steps.md

@@ -0,0 +1 @@
+- **fix(api):** `POST /api/playground/simulate-route` maps persisted schema-v2 combo steps instead of reading a `targets` field that no longer exists, fixing the HTTP 500 on every combo in the Combo Playground ([#11882](https://github.com/diegosouzapw/OmniRoute/pull/11882)) — thanks @NoxzRCW

src/app/api/playground/simulate-route/route.ts

@@ -8,6 +8,7 @@
 import { NextResponse } from "next/server";
 import { z } from "zod";
 import { getCombos } from "@/lib/db/combos";
+import { comboStepsToTargets } from "@/lib/combos/simulatorTargets";
 import { getProviderConnections } from "@/lib/db/providers";
 import { isValidationFailure, validateBody } from "@/shared/validation/helpers";
 
@@ -152,7 +153,7 @@ export async function POST(request: Request) {
         errors.push(`Combo "${body.comboId}" not found.`);
         return NextResponse.json({ error: "Combo not found" }, { status: 404 });
       }
-      const targets = typeof combo.targets === "string" ? JSON.parse(combo.targets) : combo.targets;
+      const targets = comboStepsToTargets(combo, warnings);
       comboInfo = { name: combo.name, strategy: combo.strategy, targets };
     } else if (body.combo) {
       comboInfo = body.combo;

src/lib/combos/simulatorTargets.ts

@@ -0,0 +1,84 @@
+/**
+ * @file simulatorTargets.ts
+ * @description Map persisted combo steps (schema v2) onto the flat target shape
+ * used by the Combo Playground simulator.
+ */
+
+export interface SimulatorTarget {
+  provider: string;
+  model: string;
+  weight?: number;
+}
+
+/**
+ * Persisted combos are stored in schema v2 (`normalizeComboRecord`), whose steps
+ * live under `models: ComboStep[]` — there is no top-level `targets` array. The
+ * simulator used to read `combo.targets`, which is always `undefined` for a
+ * persisted combo, so the target loop threw
+ * "Cannot read properties of undefined (reading 'length')" and every request
+ * returned HTTP 500 (#11822).
+ *
+ * Map the three step kinds onto the simulator's flat target shape. The provider
+ * comes from `step.providerId` or the `provider/model` prefix of `step.model` —
+ * never a top-level `step.provider`, which does not exist.
+ */
+export function comboStepsToTargets(
+  combo: Record<string, unknown>,
+  warnings: string[]
+): SimulatorTarget[] {
+  const raw = (combo as { models?: unknown }).models;
+  const steps: unknown[] = Array.isArray(raw)
+    ? raw
+    : typeof raw === "string"
+      ? (() => {
+          try {
+            const parsed: unknown = JSON.parse(raw);
+            return Array.isArray(parsed) ? parsed : [];
+          } catch {
+            return [];
+          }
+        })()
+      : [];
+
+  const targets: SimulatorTarget[] = [];
+
+  for (const step of steps) {
+    if (!step || typeof step !== "object") continue;
+    const s = step as Record<string, unknown>;
+    const weight = typeof s.weight === "number" ? s.weight : undefined;
+
+    if (s.kind === "combo-ref") {
+      warnings.push(
+        `Step references combo "${String(s.comboName)}" — nested combos are not expanded by the simulator.`
+      );
+      continue;
+    }
+
+    if (s.kind === "provider-wildcard") {
+      warnings.push(
+        `Step "${String(s.providerId)}/${String(s.modelPattern)}" is a provider wildcard — expanded at runtime, shown here unresolved.`
+      );
+      targets.push({
+        provider: String(s.providerId ?? "unknown"),
+        model: String(s.modelPattern ?? "*"),
+        weight,
+      });
+      continue;
+    }
+
+    const modelRef = typeof s.model === "string" ? s.model : "";
+    if (!modelRef) continue;
+    const slash = modelRef.indexOf("/");
+    const prefixProvider = slash > 0 ? modelRef.slice(0, slash) : null;
+    const bareModel = slash > 0 ? modelRef.slice(slash + 1) : modelRef;
+    const providerId = typeof s.providerId === "string" && s.providerId ? s.providerId : null;
+
+    targets.push({
+      provider: providerId ?? prefixProvider ?? "unknown",
+      model: bareModel,
+      weight,
+    });
+  }
+
+  return targets;
+}

tests/unit/playground-simulate-route-combo-steps-11822.test.ts

@@ -0,0 +1,96 @@
+/**
+ * Regression for #11822 — POST /api/playground/simulate-route returned HTTP 500
+ * ("Simulation error: Cannot read properties of undefined (reading 'length')")
+ * for every persisted combo, making the Combo Playground page unusable.
+ *
+ * The route read `combo.targets`, but `getCombos()` returns records normalized
+ * by `normalizeComboRecord()` — schema version 2, whose steps live under
+ * `models: ComboStep[]`. There is no `targets` property, so the target loop
+ * dereferenced `undefined.length`. The inline `body.combo` branch worked only
+ * because the caller supplies `targets` explicitly.
+ *
+ * A second, quieter mismatch: a step's provider comes from `step.providerId` or
+ * the `provider/model` prefix of `step.model`, never a top-level `step.provider`
+ * — so the connection lookup would have produced spurious
+ * "Provider undefined not configured" warnings even once targets were populated.
+ *
+ * Runner: node --import tsx/esm --test tests/unit/playground-simulate-route-combo-steps-11822.test.ts
+ */
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const { comboStepsToTargets } = await import("../../src/lib/combos/simulatorTargets.ts");
+
+test("#11822 — model steps map to targets, provider from prefix or providerId", () => {
+  const warnings: string[] = [];
+  const targets = comboStepsToTargets(
+    {
+      id: "abc",
+      name: "h-route-claude-opus-5",
+      strategy: "priority",
+      version: 2,
+      models: [
+        { id: "s1", kind: "model", model: "cc/claude-opus-5", weight: 1 },
+        { id: "s2", kind: "model", model: "anthropic/claude-opus-5", weight: 2 },
+        { id: "s3", kind: "model", model: "gpt-5", providerId: "openai", weight: 1 },
+      ],
+    },
+    warnings
+  );
+
+  assert.deepEqual(targets, [
+    { provider: "cc", model: "claude-opus-5", weight: 1 },
+    { provider: "anthropic", model: "claude-opus-5", weight: 2 },
+    { provider: "openai", model: "gpt-5", weight: 1 },
+  ]);
+  assert.deepEqual(warnings, []);
+});
+
+test("#11822 — providerId wins over the model prefix when both are present", () => {
+  const targets = comboStepsToTargets(
+    { models: [{ kind: "model", model: "anthropic/claude-opus-5", providerId: "cc", weight: 1 }] },
+    []
+  );
+  assert.equal(targets[0].provider, "cc");
+  assert.equal(targets[0].model, "claude-opus-5");
+});
+
+test("#11822 — combo-ref steps are surfaced as a warning, not silently dropped", () => {
+  const warnings: string[] = [];
+  const targets = comboStepsToTargets(
+    { models: [{ kind: "combo-ref", comboName: "backup-route", weight: 1 }] },
+    warnings
+  );
+  assert.deepEqual(targets, []);
+  assert.equal(warnings.length, 1);
+  assert.match(warnings[0], /backup-route/);
+});
+
+test("#11822 — provider-wildcard steps are shown unresolved, with a warning", () => {
+  const warnings: string[] = [];
+  const targets = comboStepsToTargets(
+    {
+      models: [
+        { kind: "provider-wildcard", providerId: "groq", modelPattern: "llama-*", weight: 1 },
+      ],
+    },
+    warnings
+  );
+  assert.deepEqual(targets, [{ provider: "groq", model: "llama-*", weight: 1 }]);
+  assert.equal(warnings.length, 1);
+});
+
+test("#11822 — malformed or absent step lists degrade to an empty target list", () => {
+  assert.deepEqual(comboStepsToTargets({ name: "no-models" }, []), []);
+  assert.deepEqual(comboStepsToTargets({ models: null }, []), []);
+  assert.deepEqual(comboStepsToTargets({ models: "{{{ not json" }, []), []);
+  assert.deepEqual(comboStepsToTargets({ models: [null, 42, {}] }, []), []);
+});
+
+test("#11822 — a serialized models column is parsed", () => {
+  const targets = comboStepsToTargets(
+    { models: JSON.stringify([{ kind: "model", model: "openai/gpt-5", weight: 3 }]) },
+    []
+  );
+  assert.deepEqual(targets, [{ provider: "openai", model: "gpt-5", weight: 3 }]);
+});