From 38bbb656da2659088e30a1ca3e4434b2f65bab32 Mon Sep 17 00:00:00 2001
From: Kaoru0822 <208281322+kaoru0822-kitauji@users.noreply.github.com>
Date: Thu, 8 Oct 2026 14:09:28 +0000
Subject: [PATCH] fix(evidence): require a complete record before the
 single-record hint

A malformed bundle that merely has an evidence_id field was described
as one Evidence record. Use the single-record message only when the
input matches the Evidence record schema; otherwise report the bundle
schema failure.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/domain/evidenceBundle.ts                      | 12 +++---------
 .../filesystem/evidenceBundleFiles.test.ts        | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/domain/evidenceBundle.ts b/src/domain/evidenceBundle.ts
index 1184ed86f..807781b66 100644
--- a/src/domain/evidenceBundle.ts
+++ b/src/domain/evidenceBundle.ts
@@ -190,15 +190,9 @@ export const describeEvidenceBundleFailure = (
   input: unknown,
   cause: unknown,
 ): string => {
-  if (
-    typeof input === "object" &&
-    input !== null &&
-    !Array.isArray(input) &&
-    "evidence_id" in input &&
-    typeof input.evidence_id === "string" &&
-    !("records" in input)
-  )
-    return `Expected an Evidence bundle with records and manifest arrays, but this JSON is one Evidence record (${input.evidence_id}). Export a session bundle with the MCP export_evidence_bundle tool and supply that file.`;
+  const record = evidenceRecordSchema.safeParse(input);
+  if (record.success)
+    return `Expected an Evidence bundle with records and manifest arrays, but this JSON is one Evidence record (${record.data.evidence_id}). Export a session bundle with the MCP export_evidence_bundle tool and supply that file.`;
   return cause instanceof z.ZodError
     ? `Evidence bundle does not match the bundle schema ${describeValidationFailure(cause)}. Supply an unmodified bundle written by export_evidence_bundle or rea evidence-export.`
     : `Evidence bundle validation failed: ${describeValidationFailure(cause)}. Recreate or re-export the bundle, then try again.`;
diff --git a/tests/boundary/filesystem/evidenceBundleFiles.test.ts b/tests/boundary/filesystem/evidenceBundleFiles.test.ts
index ce61a550d..1a048449a 100644
--- a/tests/boundary/filesystem/evidenceBundleFiles.test.ts
+++ b/tests/boundary/filesystem/evidenceBundleFiles.test.ts
@@ -160,6 +160,21 @@ describe("evidence bundle filesystem adapter", () => {
       },
     });
 
+    const partial = join(directory, "partial.json");
+    await writeFile(partial, JSON.stringify({ evidence_id: "typo" }));
+    const rejected = await readEvidenceBundle(partial);
+    expect(rejected).toMatchObject({
+      ok: false,
+      error: {
+        userMessage: expect.stringContaining(
+          "does not match the bundle schema",
+        ),
+      },
+    });
+    expect(rejected).not.toMatchObject({
+      error: { userMessage: expect.stringContaining("one Evidence record") },
+    });
+
     const mismatched = join(directory, "mismatched.json");
     await writeFile(mismatched, JSON.stringify({ ...bundle(), records: {} }));
     expect(await readEvidenceBundle(mismatched)).toMatchObject({