vm.runInNewContext(code[, contextObject[, options]])

• code <string> 要编译和运行的 JavaScript 代码。

  ¥code <string> The JavaScript code to compile and run.

• contextObject <Object> | <undefined> vm.constants.DONT_CONTEXTIFY 或将成为 contextified 的对象。如果是 undefined，将创建一个空的上下文化对象以实现向后兼容。

  ¥contextObject <Object> | <undefined> Either vm.constants.DONT_CONTEXTIFY or an object that will be contextified. If undefined, an empty contextified object will be created for backwards compatibility.

• options <Object> | <string>

  • filename <string> 指定此脚本生成的堆栈跟踪中使用的文件名。默认值：'evalmachine.<anonymous>'。

    ¥filename <string> Specifies the filename used in stack traces produced by this script. Default: 'evalmachine.<anonymous>'.

  • lineOffset <number> 指定在此脚本生成的堆栈跟踪中显示的行号偏移量。默认值：0。

    ¥lineOffset <number> Specifies the line number offset that is displayed in stack traces produced by this script. Default: 0.

  • columnOffset <number> 指定在此脚本生成的堆栈跟踪中显示的第一行列号偏移量。默认值：0。

    ¥columnOffset <number> Specifies the first-line column number offset that is displayed in stack traces produced by this script. Default: 0.

  • displayErrors <boolean> 当为 true 时，如果编译 code 时出现 Error，则导致错误的代码行会附加到堆栈跟踪中。默认值：true。

    ¥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. Default: true.

  • timeout <integer> 指定终止执行前执行 code 的毫秒数。如果执行终止，则将抛出 Error。此值必须是严格的正整数。

    ¥timeout <integer> 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.

  • breakOnSigint <boolean> 如果是 true，接收 SIGINT（Ctrl+C）将终止执行并抛出 Error。已通过 process.on('SIGINT') 附加的事件的现有句柄在脚本执行期间被禁用，但在此之后继续工作。默认值：false。

    ¥breakOnSigint <boolean> If true, receiving SIGINT (Ctrl+C) will terminate execution and throw an Error. Existing handlers for the event that have been attached via process.on('SIGINT') are disabled during script execution, but continue to work after that. Default: false.

  • contextName <string> 新创建的上下文的可读名称。默认值：'VM Context i'，其中 i 是所创建上下文的升序数字索引。

    ¥contextName <string> Human-readable name of the newly created context. Default: 'VM Context i', where i is an ascending numerical index of the created context.

  • contextOrigin <string> 起源 对应于新创建的上下文，用于显示目的。来源的格式应该像 URL，但只有协议、主机和端口（如果需要），就像 URL 对象的 url.origin 属性的值。最值得注意的是，该字符串应省略尾部斜杠，因为它表示路径。默认值：''。

    ¥contextOrigin <string> Origin corresponding to the newly created context for display purposes. The origin should be formatted like a URL, but with only the scheme, host, and port (if necessary), like the value of the url.origin property of a URL object. Most notably, this string should omit the trailing slash, as that denotes a path. Default: ''.

  • contextCodeGeneration <Object>

    • strings <boolean> 如果设置为 false，则任何对 eval 或函数构造函数（Function、GeneratorFunction 等）的调用都将抛出 EvalError。默认值：true。

      ¥strings <boolean> If set to false any calls to eval or function constructors (Function, GeneratorFunction, etc) will throw an EvalError. Default: true.

    • wasm <boolean> 如果设置为 false，则任何编译 WebAssembly 模块的尝试都将抛出 WebAssembly.CompileError。默认值：true。

      ¥wasm <boolean> If set to false any attempt to compile a WebAssembly module will throw a WebAssembly.CompileError. Default: true.

  • cachedData <Buffer> | <TypedArray> | <DataView> 为所提供的源提供可选的 Buffer 或 TypedArray 或 DataView，其中包含 V8 的代码缓存数据。

    ¥cachedData <Buffer> | <TypedArray> | <DataView> Provides an optional Buffer or TypedArray, or DataView with V8's code cache data for the supplied source.

  • importModuleDynamically <Function> | <vm.constants.USE_MAIN_CONTEXT_DEFAULT_LOADER> 用于指定在调用 import() 时评估此脚本期间应如何加载模块。此选项是实验模块 API 的一部分。不建议在生产环境中使用它。详细信息参见 编译 API 中支持动态 import()。

    ¥importModuleDynamically <Function> | <vm.constants.USE_MAIN_CONTEXT_DEFAULT_LOADER> Used to specify the how the modules should be loaded during the evaluation of this script when import() is called. This option is part of the experimental modules API. We do not recommend using it in a production environment. For detailed information, see Support of dynamic import() in compilation APIs.

  • microtaskMode <string> 如果设置为 afterEvaluate，微任务（通过 Promise 和 async function 安排的任务）将在脚本运行后立即运行。在这种情况下，它们包含在 timeout 和 breakOnSigint 范围内。

    ¥microtaskMode <string> If set to afterEvaluate, microtasks (tasks scheduled through Promises and async functions) will be run immediately after the script has run. They are included in the timeout and breakOnSigint scopes in that case.

• 返回：<any> 脚本中最后一条语句执行的结果。

  ¥Returns: <any> the result of the very last statement executed in the script.

此方法是 (new vm.Script(code, options)).runInContext(vm.createContext(options), options) 的快捷方式。如果 options 是字符串，则指定文件名。

¥This method is a shortcut to (new vm.Script(code, options)).runInContext(vm.createContext(options), options). If options is a string, then it specifies the filename.

它同时做几件事：

¥It does several things at once:

1. 创建一个新的上下文。

   ¥Creates a new context.

2. 如果 contextObject 是一个对象，则使用新上下文对其进行 contextifies 操作。如果 contextObject 未定义，则创建一个新对象并对其进行 contextifies 操作。如果 contextObject 是 vm.constants.DONT_CONTEXTIFY，则不要 contextify 任何内容。

   ¥If contextObject is an object, contextifies it with the new context. If contextObject is undefined, creates a new object and contextifies it. If contextObject is vm.constants.DONT_CONTEXTIFY, don't contextify anything.

3. 将代码编译为 avm.Script

   ¥Compiles the code as avm.Script

4. 在创建的上下文中运行编译代码。代码无权访问调用此方法的范围。

   ¥Runs the compield code within the created context. The code does not have access to the scope in which this method is called.

5. 返回结果。

   ¥Returns the result.

以下示例编译并执行增加全局变量并设置新变量的代码。这些全局变量包含在 contextObject 中。

¥The following example compiles and executes code that increments a global variable and sets a new one. These globals are contained in the contextObject.

const vm = require('node:vm');

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

vm.runInNewContext('count += 1; name = "kitty"', contextObject);
console.log(contextObject);
// Prints: { animal: 'cat', count: 3, name: 'kitty' }

// This would throw if the context is created from a contextified object.
// vm.constants.DONT_CONTEXTIFY allows creating contexts with ordinary global objects that
// can be frozen.
const frozenContext = vm.runInNewContext('Object.freeze(globalThis); globalThis;', vm.constants.DONT_CONTEXTIFY); 拷贝