From 879993b9b1b08626c4daa8f3c86eeb899367babf Mon Sep 17 00:00:00 2001
From: Hare <kei.hiracchi.0928@gmail.com>
Date: Tue, 1 Sep 2026 01:41:16 +0900
Subject: [PATCH] fix: accept zero-length Companion transcripts

---
 crates/workspace-server/src/server.rs          | 12 ++++++++++++
 .../src/lib/workspace/companion/api.test.ts    | 18 ++++++++++++++++++
 .../src/lib/workspace/companion/api.ts         |  2 +-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/crates/workspace-server/src/server.rs b/crates/workspace-server/src/server.rs
index 56ffe1d9..fbdeebd6 100644
--- a/crates/workspace-server/src/server.rs
+++ b/crates/workspace-server/src/server.rs
@@ -24168,6 +24168,18 @@ mod tests {
 
         let companion_transcript = get_json(app.clone(), "/api/companion/transcript").await;
         assert_eq!(companion_transcript["total"], 0);
+        let empty_window = get_json(app.clone(), "/api/companion/transcript?start=0&limit=0").await;
+        assert_eq!(
+            empty_window,
+            json!({
+                "state": "stopped",
+                "start": 0,
+                "limit": 0,
+                "total": 0,
+                "next": null,
+                "items": [],
+            })
+        );
 
         let host_workers = get_json(app.clone(), &format!("/api/hosts/{host_id}/workers")).await;
         assert!(
diff --git a/web/workspace/src/lib/workspace/companion/api.test.ts b/web/workspace/src/lib/workspace/companion/api.test.ts
index b6855a2d..f37f86f2 100644
--- a/web/workspace/src/lib/workspace/companion/api.test.ts
+++ b/web/workspace/src/lib/workspace/companion/api.test.ts
@@ -104,6 +104,24 @@ Deno.test("Companion transcript boundary accepts only bounded user-visible items
     ],
   };
   assertEquals(parseCompanionTranscriptProjection(fixture), fixture);
+  assertEquals(
+    parseCompanionTranscriptProjection({
+      state: "stopped",
+      start: 0,
+      limit: 0,
+      total: 0,
+      next: null,
+      items: [],
+    }),
+    {
+      state: "stopped",
+      start: 0,
+      limit: 0,
+      total: 0,
+      next: null,
+      items: [],
+    },
+  );
 
   assertThrows(
     () =>
diff --git a/web/workspace/src/lib/workspace/companion/api.ts b/web/workspace/src/lib/workspace/companion/api.ts
index 132a1a9e..ba7584aa 100644
--- a/web/workspace/src/lib/workspace/companion/api.ts
+++ b/web/workspace/src/lib/workspace/companion/api.ts
@@ -63,7 +63,7 @@ export function parseCompanionTranscriptProjection(
   ]);
   const start = boundedInteger(record.start);
   const limit = boundedInteger(record.limit);
-  if (limit < 1 || limit > MAX_TRANSCRIPT_ITEMS) {
+  if (limit > MAX_TRANSCRIPT_ITEMS) {
     throw new TypeError("Companion transcript limit is out of range");
   }
   const items = boundedArray(record.items, limit).map(parseTranscriptItem);