From deed51a397be97ba31fa0811bf9ca75686137e99 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Thu, 23 Jul 2026 12:03:48 +0000
Subject: [PATCH] fix: recurse into NullableSchema.inner in assertValidSchema

assertValidSchema validated array items, record values, and object
property schemas but skipped the inner schema of NullableSchema. A
misconfigured nested schema like s.nullable(s.object({ x: 'bad' as any }))
would silently escape the early construction-time check and only surface
a confusing error at invocation time or, worse, produce a repair loop.

This adds a nullable branch that recurses into schema.inner before the
properties branch, making schema validation consistent for all composite
schema types.

Discovered while running sample 13-test-plan.ts: the sample uses
s.nullable indirectly through s.object with enum fields, and analysing
assertValidSchema revealed the gap.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 skills/rig/rig.ts | 4 ++++
 src/rig.test.ts   | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/skills/rig/rig.ts b/skills/rig/rig.ts
index 34ab2e0..1bf3059 100644
--- a/skills/rig/rig.ts
+++ b/skills/rig/rig.ts
@@ -1687,6 +1687,10 @@ function assertValidSchema(schema: Schema, agentName: string, slot: "input" | "o
     assertValidSchema(schema.additionalProperties, agentName, slot, `${path}.*`);
     return;
   }
+  if ("nullable" in schema && schema.nullable === true) {
+    assertValidSchema((schema as NullableSchema).inner, agentName, slot, path);
+    return;
+  }
   if ("properties" in schema) {
     for (const [key, value] of Object.entries(schema.properties) as [string, Schema][]) {
       assertValidSchema(value, agentName, slot, `${path}.${key}`);
diff --git a/src/rig.test.ts b/src/rig.test.ts
index 741323d..86ba91f 100644
--- a/src/rig.test.ts
+++ b/src/rig.test.ts
@@ -141,6 +141,11 @@ describe("agent", () => {
       name: "implicit-nested",
       input: s.object({ text: "go" as any }),
     })).toThrow(/input\.text/);
+
+    expect(() => agent({
+      name: "implicit-nullable-nested",
+      output: s.nullable(s.object({ score: "bad" as any })),
+    })).toThrow(/output\.score/);
   });
 
   it("does not expose deprecated hook APIs in core", () => {