TheModule object#

• <Object>

Provides general utility methods when interacting with instances ofModule, themodule variable often seen inCommonJS modules. Accessedviaimport 'module' orrequire('module').

module.builtinModules#

• <string[]>

A list of the names of all modules provided by Node.js. Can be used to verifyif a module is maintained by a third party or not.

module in this context isn't the same object that's providedby themodule wrapper. To access it, require theModule module:

// module.mjs// In an ECMAScript moduleimport { builtinModulesas builtin }from'module';// module.cjs// In a CommonJS moduleconst builtin =require('module').builtinModules;

module.createRequire(filename)#

• filename<string> |<URL> Filename to be used to construct the requirefunction. Must be a file URL object, file URL string, or absolute pathstring.
• Returns:<require> Require function

import { createRequire }from'module';constrequire =createRequire(import.meta.url);// sibling-module.js is a CommonJS module.const siblingModule =require('./sibling-module');

module.createRequireFromPath(filename)#

• filename<string> Filename to be used to construct the relative requirefunction.
• Returns:<require> Require function

const { createRequireFromPath } =require('module');const requireUtil =createRequireFromPath('../src/utils/');// Require `../src/utils/some-tool`requireUtil('./some-tool');

module.syncBuiltinESMExports()#

Themodule.syncBuiltinESMExports() method updates all the live bindings forbuiltinES Modules to match the properties of theCommonJS exports. Itdoes not add or remove exported names from theES Modules.

const fs =require('fs');const assert =require('assert');const { syncBuiltinESMExports } =require('module');fs.readFile = newAPI;delete fs.readFileSync;functionnewAPI() {// ...}fs.newAPI = newAPI;syncBuiltinESMExports();import('fs').then((esmFS) => {// It syncs the existing readFile property with the new value  assert.strictEqual(esmFS.readFile, newAPI);// readFileSync has been deleted from the required fs  assert.strictEqual('readFileSync'in fs,false);// syncBuiltinESMExports() does not remove readFileSync from esmFS  assert.strictEqual('readFileSync'in esmFS,true);// syncBuiltinESMExports() does not add names  assert.strictEqual(esmFS.newAPI,undefined);});

Source map v3 support#

Helpers for interacting with the source map cache. This cache ispopulated when source map parsing is enabled andsource map include directives are found in a modules' footer.

To enable source map parsing, Node.js must be run with the flag--enable-source-maps, or with code coverage enabled by settingNODE_V8_COVERAGE=dir.

// module.mjs// In an ECMAScript moduleimport { findSourceMap,SourceMap }from'module';// module.cjs// In a CommonJS moduleconst { findSourceMap,SourceMap } =require('module');

module.findSourceMap(path)#

• path<string>
• Returns:<module.SourceMap>

path is the resolved path for the file for which a corresponding source mapshould be fetched.

Class:module.SourceMap#

new SourceMap(payload)#

• payload<Object>

Creates a newsourceMap instance.

payload is an object with keys matching theSource map v3 format:

• file:<string>
• version:<number>
• sources:<string[]>
• sourcesContent:<string[]>
• names:<string[]>
• mappings:<string>
• sourceRoot:<string>

sourceMap.payload#

• Returns:<Object>

Getter for the payload used to construct theSourceMap instance.

sourceMap.findEntry(lineNumber, columnNumber)#

• lineNumber<number>
• columnNumber<number>
• Returns:<Object>

Given a line number and column number in the generated source file, returnsan object representing the position in the original file. The object returnedconsists of the following keys:

• generatedLine:<number>
• generatedColumn:<number>
• originalSource:<string>
• originalLine:<number>
• originalColumn:<number>
• name:<string>