fix(tabs): never crash on duplicate toolCallIds in tool batches

2 files changed, 133 insertions, 1 deletions

diff --git a/src/features/chat/ui/ChatView.svelte b/src/features/chat/ui/ChatView.svelte
index e67ca5b..6805b20 100644
--- a/src/features/chat/ui/ChatView.svelte
+++ b/src/features/chat/ui/ChatView.svelte
@@ -301,7 +301,7 @@
       <div class="chat chat-start [&>.chat-bubble]:max-w-5xl [&>.chat-bubble]:p-0">
         <div class="chat-bubble w-full bg-transparent">
           <div class="flex flex-col gap-1">
-            {#each row.group.entries as entry (entry.call.toolCallId)}
+            {#each row.group.entries as entry, entryIndex (entryIndex)}
               <div class="collapse w-full rounded-box bg-base-200 text-sm">
                 <input type="checkbox" aria-label="Toggle tool call" />
                 <div class="collapse-title flex min-h-0 items-center gap-2 py-2 font-medium">
diff --git a/src/features/chat/ui/ChatView.test.ts b/src/features/chat/ui/ChatView.test.ts
new file mode 100644
index 0000000..eb807c1
--- /dev/null
+++ b/src/features/chat/ui/ChatView.test.ts
@@ -0,0 +1,132 @@
+import type { StepId } from "@dispatch/wire";
+import { render, screen } from "@testing-library/svelte";
+import { describe, expect, it } from "vitest";
+import type { RenderedChunk } from "../../../core/chunks";
+import ChatView from "./ChatView.svelte";
+
+// Defensive rendering: a conversation transcript can contain duplicate
+// `toolCallId`s (provider double-emission, persisted — e.g. PII_REDACTED_CONVERSATION_SHORT_01). The
+// grouped render path MUST dedupe them so the keyed {#each} never throws
+// Svelte `each_key_duplicate` (which aborts the reactive flush and makes the
+// tab appear dead). See fix-toolcall-duplicate-keys plan Part 1.
+describe("ChatView — duplicate toolCallIds", () => {
+  it("renders a tool batch with duplicated toolCallIds without throwing, showing one card per unique call", () => {
+    const chunks: RenderedChunk[] = [
+      {
+        seq: 1,
+        role: "assistant",
+        chunk: {
+          type: "tool-call",
+          toolCallId: "a",
+          toolName: "read_file",
+          input: { path: "/a" },
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      {
+        seq: 2,
+        role: "assistant",
+        chunk: {
+          type: "tool-call",
+          toolCallId: "b",
+          toolName: "list_dir",
+          input: { path: "/b" },
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      // The PII_REDACTED_CONVERSATION_SHORT_01 pattern: the same ids re-emitted immediately after.
+      {
+        seq: 3,
+        role: "assistant",
+        chunk: {
+          type: "tool-call",
+          toolCallId: "a",
+          toolName: "read_file",
+          input: { path: "/a" },
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      {
+        seq: 4,
+        role: "assistant",
+        chunk: {
+          type: "tool-call",
+          toolCallId: "b",
+          toolName: "list_dir",
+          input: { path: "/b" },
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      {
+        seq: 5,
+        role: "tool",
+        chunk: {
+          type: "tool-result",
+          toolCallId: "a",
+          toolName: "read_file",
+          content: "contents-of-a",
+          isError: false,
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      {
+        seq: 6,
+        role: "tool",
+        chunk: {
+          type: "tool-result",
+          toolCallId: "b",
+          toolName: "list_dir",
+          content: "contents-of-b",
+          isError: false,
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      // Duplicate results too — absorbed into the single deduped batch.
+      {
+        seq: 7,
+        role: "tool",
+        chunk: {
+          type: "tool-result",
+          toolCallId: "a",
+          toolName: "read_file",
+          content: "contents-of-a",
+          isError: false,
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+      {
+        seq: 8,
+        role: "tool",
+        chunk: {
+          type: "tool-result",
+          toolCallId: "b",
+          toolName: "list_dir",
+          content: "contents-of-b",
+          isError: false,
+          stepId: "t1#0" as StepId,
+        },
+        provisional: false,
+      },
+    ];
+
+    const { container } = render(ChatView, { props: { chunks } });
+
+    // No each_key_duplicate crash. Batched calls render as collapsible cards —
+    // exactly ONE per unique toolCallId (deduped), not 4.
+    const collapses = container.querySelectorAll(".collapse");
+    expect(collapses).toHaveLength(2);
+
+    // Both unique tool names shown; each result rendered once (deduped).
+    expect(screen.getByText("read_file")).toBeInTheDocument();
+    expect(screen.getByText("list_dir")).toBeInTheDocument();
+    expect(screen.getByText("contents-of-a")).toBeInTheDocument();
+    expect(screen.getByText("contents-of-b")).toBeInTheDocument();
+  });
+});