codeql/javascript/ql/test/tutorials/Analyzing data flow in JavaScript/Global data flow/query3.ql

import javascript

class CheckPathSanitizerGuard extends TaintTracking::SanitizerGuardNode, DataFlow::CallNode {
  CheckPathSanitizerGuard() { this.getCalleeName() = "checkPath" }

  override predicate sanitizes(boolean outcome, Expr e) {
    outcome = true and
    e = getArgument(0).asExpr()
  }
}

class CommandLineFileNameConfiguration extends TaintTracking::Configuration {
  CommandLineFileNameConfiguration() { this = "CommandLineFileNameConfiguration" }

  override predicate isSource(DataFlow::Node source) {
    DataFlow::globalVarRef("process").getAPropertyRead("argv").getAPropertyRead() = source
  }

  override predicate isSink(DataFlow::Node sink) {
    DataFlow::moduleMember("fs", "readFile").getACall().getArgument(0) = sink
  }

  override predicate isSanitizerGuard(TaintTracking::SanitizerGuardNode nd) {
    nd instanceof CheckPathSanitizerGuard
  }
}

from CommandLineFileNameConfiguration cfg, DataFlow::Node source, DataFlow::Node sink
where cfg.hasFlow(source, sink)
select source, sink