diff --git a/src/infra/outbound/abort.test.ts b/src/infra/outbound/abort.test.ts
new file mode 100644
index 00000000000..794615b2a28
--- /dev/null
+++ b/src/infra/outbound/abort.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, it } from "vitest";
+import { throwIfAborted } from "./abort.js";
+
+describe("throwIfAborted", () => {
+  it("does nothing when the signal is missing or not aborted", () => {
+    expect(() => throwIfAborted()).not.toThrow();
+    expect(() => throwIfAborted(new AbortController().signal)).not.toThrow();
+  });
+
+  it("throws a standard AbortError when the signal is aborted", () => {
+    const controller = new AbortController();
+    controller.abort();
+
+    expect(() => throwIfAborted(controller.signal)).toThrowError(
+      expect.objectContaining({
+        name: "AbortError",
+        message: "Operation aborted",
+      }),
+    );
+  });
+});
diff --git a/src/infra/outbound/envelope.test.ts b/src/infra/outbound/envelope.test.ts
new file mode 100644
index 00000000000..68b2aa28b96
--- /dev/null
+++ b/src/infra/outbound/envelope.test.ts
@@ -0,0 +1,55 @@
+import { describe, expect, it } from "vitest";
+import type { ReplyPayload } from "../../auto-reply/types.js";
+import { buildOutboundResultEnvelope } from "./envelope.js";
+import type { OutboundDeliveryJson } from "./format.js";
+
+describe("buildOutboundResultEnvelope", () => {
+  const delivery: OutboundDeliveryJson = {
+    channel: "telegram",
+    via: "direct",
+    to: "123",
+    messageId: "m1",
+    mediaUrl: null,
+    chatId: "c1",
+  };
+
+  it("flattens delivery by default when nothing else is present", () => {
+    expect(buildOutboundResultEnvelope({ delivery })).toEqual(delivery);
+  });
+
+  it("keeps pre-normalized payload JSON entries but clones the array", () => {
+    const payloads = [{ text: "hi", mediaUrl: null, mediaUrls: undefined }];
+
+    const envelope = buildOutboundResultEnvelope({
+      payloads,
+      meta: { ok: true },
+    });
+
+    expect(envelope).toEqual({
+      payloads: [{ text: "hi", mediaUrl: null, mediaUrls: undefined }],
+      meta: { ok: true },
+    });
+    expect((envelope as { payloads: unknown[] }).payloads).not.toBe(payloads);
+  });
+
+  it("normalizes reply payloads and keeps wrapped delivery when flattening is disabled", () => {
+    const payloads: ReplyPayload[] = [{ text: "hello" }];
+
+    expect(
+      buildOutboundResultEnvelope({
+        payloads,
+        delivery,
+        flattenDelivery: false,
+      }),
+    ).toEqual({
+      payloads: [
+        {
+          text: "hello",
+          mediaUrl: null,
+          channelData: undefined,
+        },
+      ],
+      delivery,
+    });
+  });
+});
diff --git a/src/infra/outbound/outbound.test.ts b/src/infra/outbound/outbound.test.ts
index 72ccf3e3c55..b04c0462e43 100644
--- a/src/infra/outbound/outbound.test.ts
+++ b/src/infra/outbound/outbound.test.ts
@@ -19,8 +19,6 @@ import {
   recoverPendingDeliveries,
 } from "./delivery-queue.js";
 import { DirectoryCache } from "./directory-cache.js";
-import { buildOutboundResultEnvelope } from "./envelope.js";
-import type { OutboundDeliveryJson } from "./format.js";
 import {
   buildOutboundDeliveryJson,
   formatGatewaySummary,
@@ -670,73 +668,6 @@ describe("DirectoryCache", () => {
   });
 });
 
-describe("buildOutboundResultEnvelope", () => {
-  it("formats envelope variants", () => {
-    const whatsappDelivery: OutboundDeliveryJson = {
-      channel: "whatsapp",
-      via: "gateway",
-      to: "+1",
-      messageId: "m1",
-      mediaUrl: null,
-    };
-    const telegramDelivery: OutboundDeliveryJson = {
-      channel: "telegram",
-      via: "direct",
-      to: "123",
-      messageId: "m2",
-      mediaUrl: null,
-      chatId: "c1",
-    };
-    const discordDelivery: OutboundDeliveryJson = {
-      channel: "discord",
-      via: "gateway",
-      to: "channel:C1",
-      messageId: "m3",
-      mediaUrl: null,
-      channelId: "C1",
-    };
-    const cases = typedCases<{
-      name: string;
-      input: Parameters<typeof buildOutboundResultEnvelope>[0];
-      expected: unknown;
-    }>([
-      {
-        name: "flatten delivery by default",
-        input: { delivery: whatsappDelivery },
-        expected: whatsappDelivery,
-      },
-      {
-        name: "keep payloads + meta",
-        input: {
-          payloads: [{ text: "hi", mediaUrl: null, mediaUrls: undefined }],
-          meta: { foo: "bar" },
-        },
-        expected: {
-          payloads: [{ text: "hi", mediaUrl: null, mediaUrls: undefined }],
-          meta: { foo: "bar" },
-        },
-      },
-      {
-        name: "include delivery when payloads exist",
-        input: { payloads: [], delivery: telegramDelivery, meta: { ok: true } },
-        expected: {
-          payloads: [],
-          meta: { ok: true },
-          delivery: telegramDelivery,
-        },
-      },
-      {
-        name: "keep wrapped delivery when flatten disabled",
-        input: { delivery: discordDelivery, flattenDelivery: false },
-        expected: { delivery: discordDelivery },
-      },
-    ]);
-    for (const testCase of cases) {
-      expect(buildOutboundResultEnvelope(testCase.input), testCase.name).toEqual(testCase.expected);
-    }
-  });
-});
-
 describe("formatOutboundDeliverySummary", () => {
   it("formats fallback and channel-specific detail variants", () => {
     const cases = [
diff --git a/src/infra/ws.test.ts b/src/infra/ws.test.ts
new file mode 100644
index 00000000000..be7a98c2133
--- /dev/null
+++ b/src/infra/ws.test.ts
@@ -0,0 +1,19 @@
+import { Buffer } from "node:buffer";
+import { describe, expect, it } from "vitest";
+import { rawDataToString } from "./ws.js";
+
+describe("rawDataToString", () => {
+  it("returns string input unchanged", () => {
+    expect(rawDataToString("hello")).toBe("hello");
+  });
+
+  it("decodes Buffer, Buffer[] and ArrayBuffer inputs", () => {
+    expect(rawDataToString(Buffer.from("hello"))).toBe("hello");
+    expect(rawDataToString([Buffer.from("he"), Buffer.from("llo")])).toBe("hello");
+    expect(rawDataToString(Uint8Array.from([104, 101, 108, 108, 111]).buffer)).toBe("hello");
+  });
+
+  it("falls back to string coercion for other raw data shapes", () => {
+    expect(rawDataToString(Uint8Array.from([1, 2, 3]) as never)).toBe("1,2,3");
+  });
+});