test(server): reproduce mixed-script file search and preserve existing matches

Record the reported ordering and matching expectations alongside existing Cyrillic, Korean, punctuation, and long-path searches. The reported expectations fail on main; compatibility checks expose regressions in the proposed replacement. Matching policy remains undecided; no production behavior changes.

Co-authored-by: Ouyang Xingyuan <galaxyroaming@qq.com>

packages/server/src/utils/directory-suggestions.7650.test.ts

@@ -0,0 +1,78 @@
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import path from "node:path";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+import { searchDirectoryEntries } from "./directory-suggestions.js";
+
+const reportedFiles = [
+  "data/prices/claude.json",
+  "docs/architecture.ts",
+  "docs/reference/ai模型价格-Claude.md",
+  "scripts/cleanup_codex_cua_orphans.sh",
+  "src/chat-input.tsx",
+  "src/chronicle.ts",
+];
+const longPath = `needle/${"a".repeat(80)}/${"b".repeat(80)}/file.txt`;
+
+// Keep diagnostic fixtures in the workspace, separate from the user's files.
+function fixture(files: string[]): string {
+  const artifacts = path.resolve(import.meta.dirname, "../../../../.artifacts");
+  mkdirSync(artifacts, { recursive: true });
+  const root = mkdtempSync(path.join(artifacts, "file-search-7650-"));
+  for (const file of files) {
+    const target = path.join(root, file);
+    mkdirSync(path.dirname(target), { recursive: true });
+    writeFileSync(target, "");
+  }
+  return root;
+}
+
+async function search(root: string, query: string): Promise<string[]> {
+  return (
+    await searchDirectoryEntries({
+      root,
+      query,
+      pathFormat: "relative",
+      pathQueryPolicy: "slashes",
+      includeFiles: true,
+      includeDirectories: false,
+    })
+  ).map((entry) => entry.path);
+}
+
+describe("#7650 reported search expectations", () => {
+  let root: string;
+  beforeAll(() => {
+    root = fixture(reportedFiles);
+  });
+  afterAll(() => rmSync(root, { recursive: true, force: true }));
+
+  it("requires both parts of a mixed-script query", async () => {
+    expect(await search(root, "claude价格")).toEqual(["docs/reference/ai模型价格-Claude.md"]);
+  });
+
+  it("prefers the filename abbreviation over a mid-word substring", async () => {
+    expect(await search(root, "chi")).toEqual([
+      "src/chat-input.tsx",
+      "src/chronicle.ts",
+      "docs/architecture.ts",
+    ]);
+  });
+});
+
+describe("#7650 existing search compatibility", () => {
+  let root: string;
+  beforeAll(() => {
+    root = fixture(["привет.md", "설정.md", "résumé.md", "---.md", longPath]);
+  });
+  afterAll(() => rmSync(root, { recursive: true, force: true }));
+
+  it.each([
+    ["привет", "привет.md"],
+    ["설정", "설정.md"],
+    ["résumé", "résumé.md"],
+    ["---", "---.md"],
+    ["needle", longPath],
+  ])("preserves matching for %s", async (query, expected) => {
+    expect(await search(root, query)).toContain(expected);
+  });
+});