fix(scripts): preserve emoji in request log previews (#109481)

* fix(scripts): preserve emoji in request log previews

* fix(scripts): keep mock preview standalone

* refactor(scripts): reuse UTF-16 truncation helper

Co-authored-by: Leon-SK668 <0668001470@xydigit.com>

* test(scripts): cover raw Node mock loading

Co-authored-by: Leon-SK668 <0668001470@xydigit.com>

* docs(scripts): note raw Node type stripping contract

Co-authored-by: Leon-SK668 <0668001470@xydigit.com>

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

scripts/e2e/lib/mock-openai-http.mjs

@@ -1,5 +1,7 @@
 // Mock OpenAI-compatible HTTP server helpers for E2E scenarios.
 import fs from "node:fs";
+// Raw launchers meet the repo's Node 22.22.3 minimum, where native TS stripping is enabled.
+import { truncateUtf16Safe } from "../../../packages/normalization-core/src/utf16-slice.ts";
 import { readPositiveIntEnv } from "./env-limits.mjs";
 
 const DEFAULT_REQUEST_MAX_BYTES = 4 * 1024 * 1024;
@@ -76,7 +78,7 @@ export function boundedRequestLogBody(value, bodyText, limits = readMockOpenAiHt
   return {
     truncated: true,
     byteLength,
-    preview: bodyText.slice(0, REQUEST_LOG_PREVIEW_CHARS),
+    preview: truncateUtf16Safe(bodyText, REQUEST_LOG_PREVIEW_CHARS),
   };
 }
 

test/scripts/mock-openai-http.test.ts

@@ -1,4 +1,5 @@
 // Mock Openai Http tests cover mock openai http script behavior.
+import { spawnSync } from "node:child_process";
 import { PassThrough } from "node:stream";
 import { describe, expect, it } from "vitest";
 import {
@@ -15,6 +16,17 @@ function bodyStream(text: string) {
 }
 
 describe("mock OpenAI HTTP helpers", () => {
+  it("loads under raw Node without a TypeScript loader", () => {
+    const result = spawnSync(
+      process.execPath,
+      ["--input-type=module", "--eval", "await import('./scripts/e2e/lib/mock-openai-http.mjs')"],
+      { cwd: process.cwd(), encoding: "utf8" },
+    );
+
+    expect(result.status, result.stderr).toBe(0);
+    expect(result.signal).toBeNull();
+  });
+
   it("reads request bodies within the configured ceiling", async () => {
     await expect(readBody(bodyStream("small"), { requestMaxBytes: 8 })).resolves.toBe("small");
   });
@@ -43,6 +55,20 @@ describe("mock OpenAI HTTP helpers", () => {
     });
   });
 
+  it("does not split emoji in request-log previews", () => {
+    const bodyText = `${"a".repeat(4095)}😀tail`;
+
+    expect(
+      boundedRequestLogBody({ full: bodyText }, bodyText, {
+        requestLogBodyMaxBytes: 8,
+      }),
+    ).toEqual({
+      truncated: true,
+      byteLength: Buffer.byteLength(bodyText, "utf8"),
+      preview: "a".repeat(4095),
+    });
+  });
+
   it("keeps small request-log bodies intact", () => {
     const body = { ok: true };
     expect(boundedRequestLogBody(body, JSON.stringify(body), { requestLogBodyMaxBytes: 64 })).toBe(