test(scripts): cover e2e text file utilities

test/scripts/e2e-text-file-utils.test.ts

@@ -0,0 +1,51 @@
+// E2E text file utility tests cover bounded diagnostic file reads.
+import { mkdirSync, writeFileSync } from "node:fs";
+import path from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+  readTextFileBounded,
+  readTextFileTail,
+  tailText,
+} from "../../scripts/e2e/lib/text-file-utils.mjs";
+import { cleanupTempDirs, makeTempDir } from "../helpers/temp-dir.js";
+
+const tempRoots: string[] = [];
+
+function makeTempRoot() {
+  return makeTempDir(tempRoots, "openclaw-e2e-text-file-utils-");
+}
+
+afterEach(() => {
+  cleanupTempDirs(tempRoots);
+});
+
+describe("e2e text file utilities", () => {
+  it("keeps short diagnostic text intact and trims long text by byte count", () => {
+    expect(tailText("short", 8)).toBe("short");
+    expect(tailText("prefix-tail", 4)).toBe("tail");
+  });
+
+  it("reads only the requested file tail and treats missing or non-file paths as empty", () => {
+    const root = makeTempRoot();
+    const file = path.join(root, "output.log");
+    const directory = path.join(root, "nested");
+    mkdirSync(directory);
+    writeFileSync(file, "line-one\nline-two\nline-three", "utf8");
+
+    expect(readTextFileTail(file, 10)).toBe("line-three");
+    expect(readTextFileTail(path.join(root, "missing.log"), 10)).toBe("");
+    expect(readTextFileTail(directory, 10)).toBe("");
+  });
+
+  it("returns bounded file text and reports oversize diagnostics with a tail", () => {
+    const root = makeTempRoot();
+    const file = path.join(root, "artifact.json");
+    writeFileSync(file, `old prefix\n${"x".repeat(64)}\nfinal tail`, "utf8");
+
+    expect(readTextFileBounded(file, "artifact", 256)).toContain("final tail");
+
+    expect(() => readTextFileBounded(file, "artifact", 32, { tailBytes: 10 })).toThrowError(
+      /artifact exceeded 32 bytes: .* Tail: final tail/u,
+    );
+  });
+});

test/scripts/test-projects.test.ts

@@ -420,6 +420,7 @@ describe("scripts/test-projects changed-target routing", () => {
         "scripts/e2e/lib/openwebui/http-probe.mjs",
         ["test/e2e/qa-lab/runtime/openwebui-probe.e2e.test.ts"],
       ],
+      ["scripts/e2e/lib/text-file-utils.mjs", ["test/scripts/e2e-text-file-utils.test.ts"]],
       [
         "scripts/e2e/lib/plugins/npm-registry-server.mjs",
         ["test/scripts/plugins-assertions.test.ts"],