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Node.js v15.0.0-rc.1 Documentation
Table of Contents
Modules: module
API#
The Module
object#
Provides general utility methods when interacting with instances of
Module
, the module
variable often seen in CommonJS modules. Accessed
via import 'module'
or require('module')
.
module.builtinModules
#
A list of the names of all modules provided by Node.js. Can be used to verify if a module is maintained by a third party or not.
module
in this context isn't the same object that's provided
by the module wrapper. To access it, require the Module
module:
// module.mjs
// In an ECMAScript module
import { builtinModules as builtin } from 'module';
// module.cjs
// In a CommonJS module
const builtin = require('module').builtinModules;
module.createRequire(filename)
#
filename
<string> | <URL> Filename to be used to construct the require function. Must be a file URL object, file URL string, or absolute path string.- Returns: <require> Require function
import { createRequire } from 'module';
const require = createRequire(import.meta.url);
// sibling-module.js is a CommonJS module.
const siblingModule = require('./sibling-module');
module.createRequireFromPath(filename)
#
createRequire()
instead.filename
<string> Filename to be used to construct the relative require function.- Returns: <require> Require function
const { createRequireFromPath } = require('module');
const requireUtil = createRequireFromPath('../src/utils/');
// Require `../src/utils/some-tool`
requireUtil('./some-tool');
module.syncBuiltinESMExports()
#
The module.syncBuiltinESMExports()
method updates all the live bindings for
builtin ES Modules to match the properties of the CommonJS exports. It
does not add or remove exported names from the ES Modules.
const fs = require('fs');
const { syncBuiltinESMExports } = require('module');
fs.readFile = null;
delete fs.readFileSync;
fs.newAPI = function newAPI() {
// ...
};
syncBuiltinESMExports();
import('fs').then((esmFS) => {
assert.strictEqual(esmFS.readFile, null);
assert.strictEqual('readFileSync' in fs, true);
assert.strictEqual(esmFS.newAPI, undefined);
});
Source map v3 support#
Helpers for interacting with the source map cache. This cache is populated when source map parsing is enabled and source 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 setting
NODE_V8_COVERAGE=dir
.
// module.mjs
// In an ECMAScript module
import { findSourceMap, SourceMap } from 'module';
// module.cjs
// In a CommonJS module
const { findSourceMap, SourceMap } = require('module');
module.findSourceMap(path[, error])
#
path
<string>error
<Error>- Returns: <module.SourceMap>
path
is the resolved path for the file for which a corresponding source map
should be fetched.
The error
instance should be passed as the second parameter to findSourceMap
in exceptional flows, such as when an overridden
Error.prepareStackTrace(error, trace)
is invoked. Modules are not added to
the module cache until they are successfully loaded. In these cases, source maps
are associated with the error
instance along with the path
.
Class: module.SourceMap
#
new SourceMap(payload)
#
payload
<Object>
Creates a new sourceMap
instance.
payload
is an object with keys matching the Source 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 the SourceMap
instance.
sourceMap.findEntry(lineNumber, columnNumber)
#
Given a line number and column number in the generated source file, returns an object representing the position in the original file. The object returned consists of the following keys: