phantomas/modules/javaScriptBottlenecks/scope.js

Headless Chromium-based web performance metrics collector and monitoring tool

(async function javaScriptBottlenecksScope(phantomas) {
  // spy calls to eval only when requested (issue #467)
  var spyEval = (await phantomas.getParam("spy-eval")) === true;

  if (!spyEval) {
    phantomas.log(
      'javaScriptBottlenecks: to spy calls to eval() run phantomas with "spy-eval" option set to true'
    );
  } else {
    phantomas.log("javaScriptBottlenecks: eval() calls will be checked");
  }

  function report(msg, caller, backtrace, metric) {
    phantomas.log(msg + ": from " + caller + "!");
    phantomas.log("Backtrace: " + backtrace);

    phantomas.incrMetric(metric);
    phantomas.addOffender(metric, { message: msg, caller });
  }

  // spy calls to eval()
  if (spyEval) {
    phantomas.spy(window, "eval", function (code) {
      report(
        "eval() called directly",
        phantomas.getCaller(),
        phantomas.getBacktrace(),
        "evalCalls"
      );
      phantomas.log(
        "eval'ed code: " + (code || "").substring(0, 150) + "(...)"
      );
    });
  }

  // spy calls to setTimeout / setInterval with string passed instead of a function
  phantomas.spy(window, "setTimeout", (fn) => {
    if (typeof fn !== "string") return;

    report(
      'eval() called via setTimeout("' + fn + '")',
      phantomas.getCaller(),
      phantomas.getBacktrace(),
      "evalCalls"
    );
  });

  phantomas.spy(window, "setInterval", (fn) => {
    if (typeof fn !== "string") return;

    report(
      'eval() called via setInterval("' + fn + '")',
      phantomas.getCaller(),
      phantomas.getBacktrace(),
      "evalCalls"
    );
  });

  // spy document.write(ln)
  phantomas.spy(document, "write", () => {
    report(
      "document.write() used",
      phantomas.getCaller(),
      phantomas.getBacktrace(),
      "documentWriteCalls"
    );
  });

  phantomas.spy(document, "writeln", () => {
    report(
      "document.writeln() used",
      phantomas.getCaller(),
      phantomas.getBacktrace(),
      "documentWriteCalls"
    );
  });
})(window.__phantomas);