feat: add parseClipboardDetection for safe clipboard tool parsing

Trims output and validates against whitelist, falling back to 'none'
for empty, multi-line, or unexpected values.

tailscalectl/lib.js

@@ -38,6 +38,11 @@ function buildCopyCommand(text, clipboardCmd) {
     return ["sh", "-c", "printf '%s' '" + escaped + "' | " + clipboardCmd]
 }
 
+function parseClipboardDetection(stdout) {
+    var trimmed = typeof stdout === "string" ? stdout.trim() : ""
+    return validateClipboardCmd(trimmed) ? trimmed : "none"
+}
+
 function errorMessage(cmd) {
     var messages = {
         "up": "Failed to connect to Tailscale",
@@ -52,5 +57,5 @@ function errorMessage(cmd) {
 
 // CommonJS export for Node.js tests (ignored by QML)
 if (typeof module !== "undefined" && module.exports) {
-    module.exports = { parsePeers, makeExitNodeCommand, findActiveExitNode, errorMessage, validateClipboardCmd, buildCopyCommand }
+    module.exports = { parsePeers, makeExitNodeCommand, findActiveExitNode, errorMessage, validateClipboardCmd, buildCopyCommand, parseClipboardDetection }
 }

test/lib.test.js

@@ -1,7 +1,7 @@
 import { test } from "node:test"
 import assert from "node:assert"
 import lib from "../tailscalectl/lib.js"
-const { parsePeers, makeExitNodeCommand, findActiveExitNode, errorMessage, validateClipboardCmd, buildCopyCommand } = lib
+const { parsePeers, makeExitNodeCommand, findActiveExitNode, errorMessage, validateClipboardCmd, buildCopyCommand, parseClipboardDetection } = lib
 
 test("parsePeers extracts exitNode from ExitNodeOption", () => {
     const peerMap = {
@@ -116,3 +116,30 @@ test("buildCopyCommand safely handles text with special characters", () => {
     const cmd = buildCopyCommand("it's a 'test' with \"quotes\" and\nnewlines", "wl-copy")
     assert.ok(Array.isArray(cmd))
 })
+
+// --- parseClipboardDetection ---
+
+test("parseClipboardDetection passes through expected output strings", () => {
+    assert.strictEqual(parseClipboardDetection("dms cl copy"), "dms cl copy")
+    assert.strictEqual(parseClipboardDetection("wl-copy"), "wl-copy")
+    assert.strictEqual(parseClipboardDetection("clipmanctl copy"), "clipmanctl copy")
+    assert.strictEqual(parseClipboardDetection("none"), "none")
+})
+
+test("parseClipboardDetection trims extra whitespace", () => {
+    assert.strictEqual(parseClipboardDetection("  wl-copy  \n"), "wl-copy")
+})
+
+test("parseClipboardDetection falls back to none for multi-line output", () => {
+    assert.strictEqual(parseClipboardDetection("wl-copy\nrm -rf /"), "none")
+})
+
+test("parseClipboardDetection falls back to empty output", () => {
+    assert.strictEqual(parseClipboardDetection(""), "none")
+    assert.strictEqual(parseClipboardDetection("   "), "none")
+})
+
+test("parseClipboardDetection falls back to none for unexpected strings", () => {
+    assert.strictEqual(parseClipboardDetection("xclip -selection clipboard"), "none")
+    assert.strictEqual(parseClipboardDetection("custom-tool"), "none")
+})