1 files changed, 113 insertions, 0 deletions
diff --git a/scripts/probe-tab.ts b/scripts/probe-tab.ts
new file mode 100644
index 0000000..16ad423
--- /dev/null
+++ b/scripts/probe-tab.ts
@@ -0,0 +1,113 @@
+/**
+ * Focused probe: load a selected conversation through the FE's REAL pure modules
+ * and see whether the tab's render path would throw. Not part of the test suite.
+ *
+ *   bun scripts/probe-tab.ts <conversationId>
+ */
+import "fake-indexeddb/auto";
+import type {
+  ConversationHistoryResponse,
+  ConversationMetricsResponse,
+} from "@dispatch/transport-contract";
+import {
+  applyHistory,
+  groupRenderedChunks,
+  initialState,
+  selectChunks,
+  selectMessages,
+} from "../src/core/chunks/index.ts";
+import {
+  applyDurableMetrics,
+  initialMetricsState,
+  selectOrderedTurnMetrics,
+} from "../src/core/metrics/index.ts";
+
+const HTTP_BASE = process.env.PROBE_HTTP ?? "http://localhost:24991";
+const CONV = process.argv[2];
+if (!CONV) {
+  console.error("Usage: bun scripts/probe-tab.ts <conversationId>");
+  process.exit(1);
+}
+
+async function historySync(id: string, sinceSeq: number): Promise<ConversationHistoryResponse> {
+  const url = `${HTTP_BASE}/conversations/${encodeURIComponent(id)}?sinceSeq=${sinceSeq}`;
+  const res = await fetch(url, { headers: { Origin: "http://localhost:24204" } });
+  if (!res.ok) throw new Error(`history fetch ${res.status} for ${url}`);
+  return (await res.json()) as ConversationHistoryResponse;
+}
+
+async function metricsSync(id: string): Promise<ConversationMetricsResponse> {
+  const res = await fetch(`${HTTP_BASE}/conversations/${encodeURIComponent(id)}/metrics`, {
+    headers: { Origin: "http://localhost:24204" },
+  });
+  if (!res.ok) throw new Error(`metrics fetch ${res.status}`);
+  return (await res.json()) as ConversationMetricsResponse;
+}
+
+let failures = 0;
+const record = (name: string, ok: boolean, detail?: string) => {
+  if (!ok) failures += 1;
+  console.log(`  ${ok ? "OK" : "FAIL"} ${name}${detail ? ` — ${detail}` : ""}`);
+};
+
+console.log(`Probing conversation ${CONV} via ${HTTP_BASE}`);
+
+// 1. applyHistory (the tab's cold-load path)
+try {
+  const hist = await historySync(CONV, 0);
+  const chunks = hist.chunks ?? [];
+  console.log(`  history: ${chunks.length} chunks, latestSeq=${hist.latestSeq}`);
+  let state = initialState();
+  try {
+    state = applyHistory(state, chunks as never);
+    record(
+      `applyHistory(${chunks.length} chunks)`,
+      true,
+      `state=${JSON.stringify(state).length} bytes`,
+    );
+  } catch (e) {
+    record("applyHistory", false, String(e));
+  }
+
+  // 2. selectMessages / selectChunks — what the transcript renders
+  try {
+    const messages = selectMessages(state);
+    record("selectMessages", true, `${messages.length} messages`);
+  } catch (e) {
+    record("selectMessages", false, String(e));
+  }
+
+  // 3. groupRenderedChunks — the render grouping
+  try {
+    const grouped = groupRenderedChunks(selectChunks(state));
+    record("groupRenderedChunks", true, `${grouped.length} groups`);
+  } catch (e) {
+    record("groupRenderedChunks", false, String(e));
+  }
+} catch (e) {
+  record("history load", false, String(e));
+}
+
+// 4. metrics path
+try {
+  const m = await metricsSync(CONV);
+  let ms = initialMetricsState();
+  const turns = (m as { turns?: unknown[] }).turns ?? [];
+  try {
+    ms = applyDurableMetrics(ms, turns as never);
+  } catch (e) {
+    failures += 1;
+    console.log(`  FAIL applyDurableMetrics — ${String(e)}`);
+  }
+  const ordered = selectOrderedTurnMetrics(ms);
+  record(
+    "metrics fold+apply",
+    true,
+    `${ordered.length} ordered turn metrics (${turns.length} turns)`,
+  );
+} catch (e) {
+  record("metrics load", false, String(e));
+}
+
+console.log(failures === 0 ? "\nALL OK — tab render path is clean." : `\n${failures} FAILURE(S).`);
+process.exit(failures === 0 ? 0 : 1);