feat: add parseStatusResult for safe JSON parsing of tailscale status

Wraps JSON.parse in try/catch, returns safe defaults on failure,
and delegates to existing findActiveExitNode and parsePeers.

tailscalectl/lib.js

@@ -38,6 +38,20 @@ function buildCopyCommand(text, clipboardCmd) {
     return ["sh", "-c", "printf '%s' '" + escaped + "' | " + clipboardCmd]
 }
 
+function parseStatusResult(jsonText) {
+    try {
+        const data = JSON.parse(jsonText)
+        return {
+            isConnected: data.BackendState === "Running",
+            tailscaleIP: (data.Self && data.Self.TailscaleIPs && data.Self.TailscaleIPs[0]) || "",
+            currentExitNode: findActiveExitNode(data.Peer || {}),
+            peers: parsePeers(data.Peer || {})
+        }
+    } catch (e) {
+        return { isConnected: false, tailscaleIP: "", currentExitNode: "", peers: [] }
+    }
+}
+
 function buildToggleCommand(isConnected) {
     return isConnected ? ["tailscale", "down"] : ["tailscale", "up"]
 }
@@ -61,5 +75,5 @@ 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, parseClipboardDetection, buildToggleCommand }
+    module.exports = { parsePeers, makeExitNodeCommand, findActiveExitNode, errorMessage, validateClipboardCmd, buildCopyCommand, parseClipboardDetection, buildToggleCommand, parseStatusResult }
 }

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, parseClipboardDetection, buildToggleCommand } = lib
+const { parsePeers, makeExitNodeCommand, findActiveExitNode, errorMessage, validateClipboardCmd, buildCopyCommand, parseClipboardDetection, buildToggleCommand, parseStatusResult } = lib
 
 test("parsePeers extracts exitNode from ExitNodeOption", () => {
     const peerMap = {
@@ -158,3 +158,48 @@ test("buildToggleCommand treats null and undefined as disconnected", () => {
     assert.deepStrictEqual(buildToggleCommand(null), ["tailscale", "up"])
     assert.deepStrictEqual(buildToggleCommand(undefined), ["tailscale", "up"])
 })
+
+// --- parseStatusResult ---
+
+test("parseStatusResult produces correct state from valid JSON", () => {
+    const json = JSON.stringify({
+        BackendState: "Running",
+        Self: { TailscaleIPs: ["100.64.0.5"] },
+        Peer: {
+            "key-1": { HostName: "router", TailscaleIPs: ["100.64.0.1"], Online: true, ExitNode: true, ExitNodeOption: true }
+        }
+    })
+    const state = parseStatusResult(json)
+    assert.strictEqual(state.isConnected, true)
+    assert.strictEqual(state.tailscaleIP, "100.64.0.5")
+    assert.strictEqual(state.currentExitNode, "router")
+    assert.strictEqual(state.peers.length, 1)
+})
+
+test("parseStatusResult returns safe defaults for invalid JSON", () => {
+    const state = parseStatusResult("not json at all")
+    assert.strictEqual(state.isConnected, false)
+    assert.strictEqual(state.tailscaleIP, "")
+    assert.strictEqual(state.currentExitNode, "")
+    assert.strictEqual(state.peers.length, 0)
+})
+
+test("parseStatusResult handles missing Self gracefully", () => {
+    const json = JSON.stringify({ BackendState: "Running", Peer: {} })
+    const state = parseStatusResult(json)
+    assert.strictEqual(state.isConnected, true)
+    assert.strictEqual(state.tailscaleIP, "")
+})
+
+test("parseStatusResult handles missing and empty Peer gracefully", () => {
+    const json = JSON.stringify({ BackendState: "Running", Self: { TailscaleIPs: ["100.64.0.5"] } })
+    const state = parseStatusResult(json)
+    assert.strictEqual(state.peers.length, 0)
+    assert.strictEqual(state.currentExitNode, "")
+})
+
+test("parseStatusResult sets isConnected false for non-Running BackendState", () => {
+    const json = JSON.stringify({ BackendState: "NeedsLogin", Self: { TailscaleIPs: ["100.64.0.5"] }, Peer: {} })
+    const state = parseStatusResult(json)
+    assert.strictEqual(state.isConnected, false)
+})