https://www.above.com/js/missing-js-check.js?1790916611

1(function () {
2  // -------------------------------------------------
3  // 1. Prevent Duplicate Initialization
4  // -------------------------------------------------
5  if (typeof window === "undefined" || window.__scriptLoadShieldInstalled__) {
6    return;
7  }
8  window.__scriptLoadShieldInstalled__ = true;
9
10  // -------------------------------------------------
11  // 2. Global State Management
12  // -------------------------------------------------
13  window.__scriptLoadState__ = window.__scriptLoadState__ || {
14    scriptLoadFailure: false,
15    suppressErrors: false,
16    suppressionReason: null,
17    firstFailureTime: null,
18    failedScripts: []
19  };
20
21  // Safely initialize the map, handling ancient browsers (IE8)
22  var failedScriptMap = typeof Object.create === "function" ? Object.create(null) : {};
23
24  // -------------------------------------------------
25  // 3. Deduplication & Metadata
26  // -------------------------------------------------
27  function recordFailedScript(src) {
28    src = src || "[unknown]";
29
30    // Strict equality prevents collisions with inherited Object properties
31    if (failedScriptMap[src] === true) {
32      return;
33    }
34
35    failedScriptMap[src] = true;
36
37    window.__scriptLoadState__.failedScripts.push({
38      src: src,
39      timestamp: new Date().getTime() 
40    });
41  }
42
43  // -------------------------------------------------
44  // 4. Error Suppression Activation
45  // -------------------------------------------------
46  function enableErrorSuppression() {
47    if (window.__scriptLoadState__.suppressErrors) {
48      return;
49    }
50
51    window.__scriptLoadState__.suppressErrors = true;
52
53    // Optional: If you ever want to re-enable Sentry after a few minutes, 
54    // you would add a setTimeout here to set suppressErrors back to false.
55
56    // A. Classic uncaught JS errors
57    var oldOnError = window.onerror;
58    window.onerror = function () {
59      if (window.__scriptLoadState__.suppressErrors) {
60        return true; 
61      }
62      if (typeof oldOnError === "function") {
63        return oldOnError.apply(this, arguments);
64      }
65      return false;
66    };
67
68    // B. Unhandled Promise Rejections
69    var oldUnhandledRejection = window.onunhandledrejection;
70    window.onunhandledrejection = function (e) {
71      if (window.__scriptLoadState__.suppressErrors) {
72        if (e && typeof e.preventDefault === "function") {
73          e.preventDefault();
74        }
75        return; 
76      }
77      if (typeof oldUnhandledRejection === "function") {
78        return oldUnhandledRejection.apply(this, arguments);
79      }
80    };
81  }
82
83  // -------------------------------------------------
84  // 5. Capture-Phase Event Listeners
85  // -------------------------------------------------
86  if (window.addEventListener) {
87    
88    window.addEventListener("error", function (e) {
89      var target = e.target || e.srcElement;
90      
91      var isResourceError = target && target !== window && typeof target.tagName === "string";
92      var isScriptError = isResourceError && target.tagName.toUpperCase() === "SCRIPT";
93
94      // A. A script failed to load. Shield up, and kill this event immediately.
95      if (isScriptError) {
96        var src = target.src || "[unknown]";
97        recordFailedScript(src);
98
99        window.__scriptLoadState__.scriptLoadFailure = true;
100        window.__scriptLoadState__.suppressionReason = "script-load-failure";
101        window.__scriptLoadState__.firstFailureTime = window.__scriptLoadState__.firstFailureTime || new Date().getTime();
102
103        enableErrorSuppression();
104        
105        // CRITICAL: Stop the initial script error from bubbling up to Sentry.
106        if (e) {
107          if (typeof e.stopImmediatePropagation === "function") {
108            e.stopImmediatePropagation();
109          } else if (typeof e.stopPropagation === "function") {
110            e.stopPropagation(); // Legacy browser fallback
111          }
112          if (typeof e.preventDefault === "function") {
113            e.preventDefault();
114          }
115        }
116        return; 
117      }
118
119      // B. If suppression is active, aggressively kill runtime errors.
120      if (window.__scriptLoadState__.suppressErrors && !isResourceError) {
121        if (e) {
122          if (typeof e.stopImmediatePropagation === "function") {
123            e.stopImmediatePropagation();
124          } else if (typeof e.stopPropagation === "function") {
125            e.stopPropagation(); // Legacy browser fallback
126          }
127          if (typeof e.preventDefault === "function") {
128            e.preventDefault();
129          }
130        }
131      }
132    }, true);
133
134    window.addEventListener("unhandledrejection", function (e) {
135      if (!window.__scriptLoadState__.suppressErrors) {
136        return;
137      }
138      if (e) {
139        if (typeof e.stopImmediatePropagation === "function") {
140          e.stopImmediatePropagation();
141        } else if (typeof e.stopPropagation === "function") {
142          e.stopPropagation(); // Legacy browser fallback
143        }
144        if (typeof e.preventDefault === "function") {
145          e.preventDefault();
146        }
147      }
148    }, true);
149  }
150
151  // -------------------------------------------------
152  // 6. Public API for proactive (non-event-driven) checks
153  // -------------------------------------------------
154  window.__scriptLoadState__.reportMissingDependency = function (name) {
155    recordFailedScript(name);
156    window.__scriptLoadState__.scriptLoadFailure = true;
157    window.__scriptLoadState__.suppressionReason = "dependency-missing";
158    window.__scriptLoadState__.firstFailureTime =
159      window.__scriptLoadState__.firstFailureTime || new Date().getTime();
160    enableErrorSuppression();
161  };
162
163})();