method

vm.Script.runInContext

contextifiedObject: Context,
options?: RunningScriptOptions
): any;

Runs the compiled code contained by the vm.Script object within the given contextifiedObject and returns the result. Running code does not have access to local scope.

The following example compiles code that increments a global variable, sets the value of another global variable, then execute the code multiple times. The globals are contained in the context object.

import { createContext, Script } from 'node:vm';

const context = {
  animal: 'cat',
  count: 2,
};

const script = new Script('count += 1; name = "kitty";');

createContext(context);
for (let i = 0; i < 10; ++i) {
  script.runInContext(context);
}

console.log(context);
// Prints: { animal: 'cat', count: 12, name: 'kitty' }

Using the timeout or breakOnSigint options will result in new event loops and corresponding threads being started, which have a non-zero performance overhead.

@param contextifiedObject

A contextified object as returned by the vm.createContext() method.

@returns

the result of the very last statement executed in the script.

Referenced types

interface Context

interface RunningScriptOptions

  • breakOnSigint?: boolean

    If true, the execution will be terminated when SIGINT (Ctrl+C) is received. Existing handlers for the event that have been attached via process.on('SIGINT') will be disabled during script execution, but will continue to work after that. If execution is terminated, an Error will be thrown.

  • columnOffset?: number

    Specifies the column number offset that is displayed in stack traces produced by this script.

  • displayErrors?: boolean

    When true, if an Error occurs while compiling the code, the line of code causing the error is attached to the stack trace.

  • filename?: string

    Specifies the filename used in stack traces produced by this script.

  • lineOffset?: number

    Specifies the line number offset that is displayed in stack traces produced by this script.

  • timeout?: number

    Specifies the number of milliseconds to execute code before terminating execution. If execution is terminated, an Error will be thrown. This value must be a strictly positive integer.