node/lib/internal/module.js

97 строки
2.5 KiB
JavaScript

'use strict';
exports = module.exports = {
makeRequireFunction,
stripBOM,
addBuiltinLibsToObject
};
exports.requireDepth = 0;
// Invoke with makeRequireFunction.call(module) where |module| is the
// Module object to use as the context for the require() function.
function makeRequireFunction() {
const Module = this.constructor;
const self = this;
function require(path) {
try {
exports.requireDepth += 1;
return self.require(path);
} finally {
exports.requireDepth -= 1;
}
}
function resolve(request) {
return Module._resolveFilename(request, self);
}
require.resolve = resolve;
require.main = process.mainModule;
// Enable support to add extra extension types.
require.extensions = Module._extensions;
require.cache = Module._cache;
return require;
}
/**
* Remove byte order marker. This catches EF BB BF (the UTF-8 BOM)
* because the buffer-to-string conversion in `fs.readFileSync()`
* translates it to FEFF, the UTF-16 BOM.
*/
function stripBOM(content) {
if (content.charCodeAt(0) === 0xFEFF) {
content = content.slice(1);
}
return content;
}
exports.builtinLibs = ['assert', 'buffer', 'child_process', 'cluster',
'crypto', 'dgram', 'dns', 'domain', 'events', 'fs', 'http', 'https', 'net',
'os', 'path', 'punycode', 'querystring', 'readline', 'repl', 'stream',
'string_decoder', 'tls', 'tty', 'url', 'util', 'v8', 'vm', 'zlib'];
function addBuiltinLibsToObject(object) {
// Make built-in modules available directly (loaded lazily).
exports.builtinLibs.forEach((name) => {
// Goals of this mechanism are:
// - Lazy loading of built-in modules
// - Having all built-in modules available as non-enumerable properties
// - Allowing the user to re-assign these variables as if there were no
// pre-existing globals with the same name.
const setReal = (val) => {
// Deleting the property before re-assigning it disables the
// getter/setter mechanism.
delete object[name];
object[name] = val;
};
Object.defineProperty(object, name, {
get: () => {
const lib = require(name);
// Disable the current getter/setter and set up a new
// non-enumerable property.
delete object[name];
Object.defineProperty(object, name, {
get: () => lib,
set: setReal,
configurable: true,
enumerable: false
});
return lib;
},
set: setReal,
configurable: true,
enumerable: false
});
});
}