Add shell plugin model tests

shell/plugins/services/idle/IdleModel.js

@@ -0,0 +1,52 @@
+function secondsFromConfig(value, fallback) {
+  var n = Number(value)
+  if (!isFinite(n) || n < 0) return fallback
+  return Math.floor(n)
+}
+
+function eventParts(event, count) {
+  try {
+    if (event && event.parse) return event.parse(count)
+  } catch (error) {
+  }
+  return String(event && event.data ? event.data : "").split(",")
+}
+
+function screensaverWindowsAfter(windows, address, visible) {
+  var key = String(address || "")
+  if (!key) {
+    var current = windows || {}
+    var existingCount = 0
+    for (var currentKey in current) {
+      if (current[currentKey]) existingCount++
+    }
+    return { windows: current, count: existingCount }
+  }
+
+  var next = {}
+  var count = 0
+  for (var existing in windows || {}) {
+    if (existing !== key && windows[existing]) {
+      next[existing] = true
+      count++
+    }
+  }
+
+  if (visible) {
+    next[key] = true
+    count++
+  }
+
+  return {
+    windows: next,
+    count: count
+  }
+}
+
+if (typeof module !== "undefined") {
+  module.exports = {
+    secondsFromConfig: secondsFromConfig,
+    eventParts: eventParts,
+    screensaverWindowsAfter: screensaverWindowsAfter
+  }
+}