test(matrix): fix inbound-preview test for lint and lib target

miorbnli · claude · miorbnli · commit 47618a12fdd4 · 2026-07-09T13:03:48.000+08:00
- Avoid String.prototype.isWellFormed (ES2024 lib): use the encodeURIComponent
  well-formedness probe instead, which works on the project's TS lib target.
- Replace literal string concatenation with template strings to satisfy the
  no-useless-concat lint rule. No behavior change in the assertions.

Co-Authored-By: Claude &lt;noreply@anthropic.com&gt;
diff --git a/extensions/matrix/src/matrix/monitor/handler.inbound-preview.test.ts b/extensions/matrix/src/matrix/monitor/handler.inbound-preview.test.ts
@@ -5,10 +5,9 @@ import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";
 // other supplementary-plane character straddles position 200.
 import { describe, expect, it } from "vitest";
 
+// A string containing a lone surrogate throws when passed to encodeURIComponent,
+// which is a runtime-safe well-formedness check that does not need ES2024 lib.
 function isWellFormed(value: string): boolean {
-  if (typeof value.isWellFormed === "function") {
-    return value.isWellFormed();
-  }
   try {
     encodeURIComponent(value);
     return true;
@@ -18,19 +17,21 @@ function isWellFormed(value: string): boolean {
 }
 
 describe("matrix inbound verbose preview truncation", () => {
-  // Same limit used in handler.ts for the inbound preview.
+  // Same limit used in handler.ts for the inbound preview. 😀 = \uD83D\uDE00;
+  // placing it after 199 'x' chars makes the 200th code unit a high surrogate.
   const PREVIEW_LIMIT = 200;
+  const highSurrogate = "\uD83D";
+  const lowSurrogate = "\uDE00";
+  const body = `${"x".repeat(199)}${highSurrogate}${lowSurrogate} tail`;
 
   it("keeps the preview well-formed when an emoji straddles the boundary", () => {
-    const body = "x".repeat(199) + "\uD83D\uDE00" + " tail";
     const preview = truncateUtf16Safe(body, PREVIEW_LIMIT).replace(/\n/g, "\\n");
     expect(isWellFormed(preview)).toBe(true);
     // Naive slice would split the pair and end with the lone high surrogate.
-    expect(preview.endsWith("\uD83D")).toBe(false);
+    expect(preview.endsWith(highSurrogate)).toBe(false);
   });
 
   it("reproduces the old slice bug splitting the pair", () => {
-    const body = "x".repeat(199) + "\uD83D\uDE00" + " tail";
     const buggy = body.slice(0, PREVIEW_LIMIT);
     // Documents why the helper is needed: the unguarded slice is malformed.
     expect(isWellFormed(buggy)).toBe(false);
@@ -42,7 +43,7 @@ describe("matrix inbound verbose preview truncation", () => {
   });
 
   it("leaves short input unchanged", () => {
-    const body = "hello \uD83D\uDE00";
-    expect(truncateUtf16Safe(body, PREVIEW_LIMIT)).toBe(body);
+    const short = `hello ${highSurrogate}${lowSurrogate}`;
+    expect(truncateUtf16Safe(short, PREVIEW_LIMIT)).toBe(short);
   });
 });
