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				33 KiB
			
		
		
			
		
	
	
					882 lines
				
				33 KiB
			| 
											3 years ago
										 | 'use strict'; | ||
|  | 
 | ||
|  | // The Resolver is currently experimental and might be exposed to users in the future.
 | ||
|  | 
 | ||
|  | const { | ||
|  | 	VMError | ||
|  | } = require('./bridge'); | ||
|  | const { VMScript } = require('./script'); | ||
|  | 
 | ||
|  | // This should match. Note that '\', '%' are invalid characters
 | ||
|  | // 1. name/.*
 | ||
|  | // 2. @scope/name/.*
 | ||
|  | const EXPORTS_PATTERN = /^((?:@[^/\\%]+\/)?[^/\\%]+)(\/.*)?$/; | ||
|  | 
 | ||
|  | // See https://tc39.es/ecma262/#integer-index
 | ||
|  | function isArrayIndex(key) { | ||
|  | 	const keyNum = +key; | ||
|  | 	if (`${keyNum}` !== key) return false; | ||
|  | 	return keyNum >= 0 && keyNum < 0xFFFFFFFF; | ||
|  | } | ||
|  | 
 | ||
|  | class Resolver { | ||
|  | 
 | ||
|  | 	constructor(fs, builtinModules, globalPaths, hostRequire) { | ||
|  | 		this.fs = fs; | ||
|  | 		this.builtinModules = builtinModules; | ||
|  | 		this.globalPaths = globalPaths; | ||
|  | 		this.hostRequire = hostRequire; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	init(vm) { | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathResolve(path) { | ||
|  | 		return this.fs.resolve(path); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathIsRelative(path) { | ||
|  | 		if (path === '' || path[0] !== '.') return false; | ||
|  | 		if (path.length === 1) return true; | ||
|  | 		const idx = path[1] === '.' ? 2 : 1; | ||
|  | 		if (path.length <= idx) return false; | ||
|  | 		return this.fs.isSeparator(path[idx]); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathIsAbsolute(path) { | ||
|  | 		return path !== '' && (this.fs.isSeparator(path[0]) || this.fs.isAbsolute(path)); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathConcat(...paths) { | ||
|  | 		return this.fs.join(...paths); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathBasename(path) { | ||
|  | 		return this.fs.basename(path); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathDirname(path) { | ||
|  | 		return this.fs.dirname(path); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	lookupPaths(mod, id) { | ||
|  | 		if (typeof id === 'string') throw new Error('Id is not a string'); | ||
|  | 		if (this.pathIsRelative(id)) return [mod.path || '.']; | ||
|  | 		return [...mod.paths, ...this.globalPaths]; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	getBuiltinModulesList() { | ||
|  | 		return Object.getOwnPropertyNames(this.builtinModules); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadBuiltinModule(vm, id) { | ||
|  | 		const handler = this.builtinModules[id]; | ||
|  | 		return handler && handler(this, vm, id); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadJS(vm, mod, filename) { | ||
|  | 		throw new VMError(`Access denied to require '${filename}'`, 'EDENIED'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadJSON(vm, mod, filename) { | ||
|  | 		throw new VMError(`Access denied to require '${filename}'`, 'EDENIED'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadNode(vm, mod, filename) { | ||
|  | 		throw new VMError(`Access denied to require '${filename}'`, 'EDENIED'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	registerModule(mod, filename, path, parent, direct) { | ||
|  | 
 | ||
|  | 	} | ||
|  | 
 | ||
|  | 	resolve(mod, x, options, ext, direct) { | ||
|  | 		if (typeof x !== 'string') throw new Error('Id is not a string'); | ||
|  | 
 | ||
|  | 		if (x.startsWith('node:') || this.builtinModules[x]) { | ||
|  | 			// a. return the core module
 | ||
|  | 			// b. STOP
 | ||
|  | 			return x; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		return this.resolveFull(mod, x, options, ext, direct); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	resolveFull(mod, x, options, ext, direct) { | ||
|  | 		// 7. THROW "not found"
 | ||
|  | 		throw new VMError(`Cannot find module '${x}'`, 'ENOTFOUND'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// NODE_MODULES_PATHS(START)
 | ||
|  | 	genLookupPaths(path) { | ||
|  | 		// 1. let PARTS = path split(START)
 | ||
|  | 		// 2. let I = count of PARTS - 1
 | ||
|  | 		// 3. let DIRS = []
 | ||
|  | 		const dirs = []; | ||
|  | 		// 4. while I >= 0,
 | ||
|  | 		while (true) { | ||
|  | 			const name = this.pathBasename(path); | ||
|  | 			// a. if PARTS[I] = "node_modules" CONTINUE
 | ||
|  | 			if (name !== 'node_modules') { | ||
|  | 				// b. DIR = path join(PARTS[0 .. I] + "node_modules")
 | ||
|  | 				// c. DIRS = DIR + DIRS // Note: this seems wrong. Should be DIRS + DIR
 | ||
|  | 				dirs.push(this.pathConcat(path, 'node_modules')); | ||
|  | 			} | ||
|  | 			const dir = this.pathDirname(path); | ||
|  | 			if (dir == path) break; | ||
|  | 			// d. let I = I - 1
 | ||
|  | 			path = dir; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		return dirs; | ||
|  | 		// This is done later on
 | ||
|  | 		// 5. return DIRS + GLOBAL_FOLDERS
 | ||
|  | 	} | ||
|  | 
 | ||
|  | } | ||
|  | 
 | ||
|  | class DefaultResolver extends Resolver { | ||
|  | 
 | ||
|  | 	constructor(fs, builtinModules, checkPath, globalPaths, pathContext, customResolver, hostRequire, compiler, strict) { | ||
|  | 		super(fs, builtinModules, globalPaths, hostRequire); | ||
|  | 		this.checkPath = checkPath; | ||
|  | 		this.pathContext = pathContext; | ||
|  | 		this.customResolver = customResolver; | ||
|  | 		this.compiler = compiler; | ||
|  | 		this.strict = strict; | ||
|  | 		this.packageCache = {__proto__: null}; | ||
|  | 		this.scriptCache = {__proto__: null}; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	isPathAllowed(path) { | ||
|  | 		return this.checkPath(path); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathTestIsDirectory(path) { | ||
|  | 		try { | ||
|  | 			const stat = this.fs.statSync(path, {__proto__: null, throwIfNoEntry: false}); | ||
|  | 			return stat && stat.isDirectory(); | ||
|  | 		} catch (e) { | ||
|  | 			return false; | ||
|  | 		} | ||
|  | 	} | ||
|  | 
 | ||
|  | 	pathTestIsFile(path) { | ||
|  | 		try { | ||
|  | 			const stat = this.fs.statSync(path, {__proto__: null, throwIfNoEntry: false}); | ||
|  | 			return stat && stat.isFile(); | ||
|  | 		} catch (e) { | ||
|  | 			return false; | ||
|  | 		} | ||
|  | 	} | ||
|  | 
 | ||
|  | 	readFile(path) { | ||
|  | 		return this.fs.readFileSync(path, {encoding: 'utf8'}); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	readFileWhenExists(path) { | ||
|  | 		return this.pathTestIsFile(path) ? this.readFile(path) : undefined; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	readScript(filename) { | ||
|  | 		let script = this.scriptCache[filename]; | ||
|  | 		if (!script) { | ||
|  | 			script = new VMScript(this.readFile(filename), {filename, compiler: this.compiler}); | ||
|  | 			this.scriptCache[filename] = script; | ||
|  | 		} | ||
|  | 		return script; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	checkAccess(mod, filename) { | ||
|  | 		if (!this.isPathAllowed(filename)) { | ||
|  | 			throw new VMError(`Module '${filename}' is not allowed to be required. The path is outside the border!`, 'EDENIED'); | ||
|  | 		} | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadJS(vm, mod, filename) { | ||
|  | 		filename = this.pathResolve(filename); | ||
|  | 		this.checkAccess(mod, filename); | ||
|  | 		if (this.pathContext(filename, 'js') === 'sandbox') { | ||
|  | 			const script = this.readScript(filename); | ||
|  | 			vm.run(script, {filename, strict: this.strict, module: mod, wrapper: 'none', dirname: mod.path}); | ||
|  | 		} else { | ||
|  | 			const m = this.hostRequire(filename); | ||
|  | 			mod.exports = vm.readonly(m); | ||
|  | 		} | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadJSON(vm, mod, filename) { | ||
|  | 		filename = this.pathResolve(filename); | ||
|  | 		this.checkAccess(mod, filename); | ||
|  | 		const json = this.readFile(filename); | ||
|  | 		mod.exports = vm._jsonParse(json); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadNode(vm, mod, filename) { | ||
|  | 		filename = this.pathResolve(filename); | ||
|  | 		this.checkAccess(mod, filename); | ||
|  | 		if (this.pathContext(filename, 'node') === 'sandbox') throw new VMError('Native modules can be required only with context set to \'host\'.'); | ||
|  | 		const m = this.hostRequire(filename); | ||
|  | 		mod.exports = vm.readonly(m); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// require(X) from module at path Y
 | ||
|  | 	resolveFull(mod, x, options, ext, direct) { | ||
|  | 		// Note: core module handled by caller
 | ||
|  | 
 | ||
|  | 		const extList = Object.getOwnPropertyNames(ext); | ||
|  | 		const path = mod.path || '.'; | ||
|  | 
 | ||
|  | 		// 5. LOAD_PACKAGE_SELF(X, dirname(Y))
 | ||
|  | 		let f = this.loadPackageSelf(x, path, extList); | ||
|  | 		if (f) return f; | ||
|  | 
 | ||
|  | 		// 4. If X begins with '#'
 | ||
|  | 		if (x[0] === '#') { | ||
|  | 			// a. LOAD_PACKAGE_IMPORTS(X, dirname(Y))
 | ||
|  | 			f = this.loadPackageImports(x, path, extList); | ||
|  | 			if (f) return f; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		// 2. If X begins with '/'
 | ||
|  | 		if (this.pathIsAbsolute(x)) { | ||
|  | 			// a. set Y to be the filesystem root
 | ||
|  | 			f = this.loadAsFileOrDirecotry(x, extList); | ||
|  | 			if (f) return f; | ||
|  | 
 | ||
|  | 			// c. THROW "not found"
 | ||
|  | 			throw new VMError(`Cannot find module '${x}'`, 'ENOTFOUND'); | ||
|  | 
 | ||
|  | 		// 3. If X begins with './' or '/' or '../'
 | ||
|  | 		} else if (this.pathIsRelative(x)) { | ||
|  | 			if (typeof options === 'object' && options !== null) { | ||
|  | 				const paths = options.paths; | ||
|  | 				if (Array.isArray(paths)) { | ||
|  | 					for (let i = 0; i < paths.length; i++) { | ||
|  | 						// a. LOAD_AS_FILE(Y + X)
 | ||
|  | 						// b. LOAD_AS_DIRECTORY(Y + X)
 | ||
|  | 						f = this.loadAsFileOrDirecotry(this.pathConcat(paths[i], x), extList); | ||
|  | 						if (f) return f; | ||
|  | 					} | ||
|  | 				} else if (paths === undefined) { | ||
|  | 					// a. LOAD_AS_FILE(Y + X)
 | ||
|  | 					// b. LOAD_AS_DIRECTORY(Y + X)
 | ||
|  | 					f = this.loadAsFileOrDirecotry(this.pathConcat(path, x), extList); | ||
|  | 					if (f) return f; | ||
|  | 				} else { | ||
|  | 					throw new VMError('Invalid options.paths option.'); | ||
|  | 				} | ||
|  | 			} else { | ||
|  | 				// a. LOAD_AS_FILE(Y + X)
 | ||
|  | 				// b. LOAD_AS_DIRECTORY(Y + X)
 | ||
|  | 				f = this.loadAsFileOrDirecotry(this.pathConcat(path, x), extList); | ||
|  | 				if (f) return f; | ||
|  | 			} | ||
|  | 
 | ||
|  | 			// c. THROW "not found"
 | ||
|  | 			throw new VMError(`Cannot find module '${x}'`, 'ENOTFOUND'); | ||
|  | 		} | ||
|  | 
 | ||
|  | 		let dirs; | ||
|  | 		if (typeof options === 'object' && options !== null) { | ||
|  | 			const paths = options.paths; | ||
|  | 			if (Array.isArray(paths)) { | ||
|  | 				dirs = []; | ||
|  | 
 | ||
|  | 				for (let i = 0; i < paths.length; i++) { | ||
|  | 					const lookups = this.genLookupPaths(paths[i]); | ||
|  | 					for (let j = 0; j < lookups.length; j++) { | ||
|  | 						if (!dirs.includes(lookups[j])) dirs.push(lookups[j]); | ||
|  | 					} | ||
|  | 					if (i === 0) { | ||
|  | 						const globalPaths = this.globalPaths; | ||
|  | 						for (let j = 0; j < globalPaths.length; j++) { | ||
|  | 							if (!dirs.includes(globalPaths[j])) dirs.push(globalPaths[j]); | ||
|  | 						} | ||
|  | 					} | ||
|  | 				} | ||
|  | 			} else if (paths === undefined) { | ||
|  | 				dirs = [...mod.paths, ...this.globalPaths]; | ||
|  | 			} else { | ||
|  | 				throw new VMError('Invalid options.paths option.'); | ||
|  | 			} | ||
|  | 		} else { | ||
|  | 			dirs = [...mod.paths, ...this.globalPaths]; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		// 6. LOAD_NODE_MODULES(X, dirname(Y))
 | ||
|  | 		f = this.loadNodeModules(x, dirs, extList); | ||
|  | 		if (f) return f; | ||
|  | 
 | ||
|  | 		f = this.customResolver(this, x, path, extList); | ||
|  | 		if (f) return f; | ||
|  | 
 | ||
|  | 		return super.resolveFull(mod, x, options, ext, direct); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	loadAsFileOrDirecotry(x, extList) { | ||
|  | 		// a. LOAD_AS_FILE(X)
 | ||
|  | 		const f = this.loadAsFile(x, extList); | ||
|  | 		if (f) return f; | ||
|  | 		// b. LOAD_AS_DIRECTORY(X)
 | ||
|  | 		return this.loadAsDirectory(x, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	tryFile(x) { | ||
|  | 		x = this.pathResolve(x); | ||
|  | 		return this.isPathAllowed(x) && this.pathTestIsFile(x) ? x : undefined; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	tryWithExtension(x, extList) { | ||
|  | 		for (let i = 0; i < extList.length; i++) { | ||
|  | 			const ext = extList[i]; | ||
|  | 			if (ext !== this.pathBasename(ext)) continue; | ||
|  | 			const f = this.tryFile(x + ext); | ||
|  | 			if (f) return f; | ||
|  | 		} | ||
|  | 		return undefined; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	readPackage(path) { | ||
|  | 		const packagePath = this.pathResolve(this.pathConcat(path, 'package.json')); | ||
|  | 
 | ||
|  | 		const cache = this.packageCache[packagePath]; | ||
|  | 		if (cache !== undefined) return cache; | ||
|  | 
 | ||
|  | 		if (!this.isPathAllowed(packagePath)) return undefined; | ||
|  | 		const content = this.readFileWhenExists(packagePath); | ||
|  | 		if (!content) { | ||
|  | 			this.packageCache[packagePath] = false; | ||
|  | 			return false; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		let parsed; | ||
|  | 		try { | ||
|  | 			parsed = JSON.parse(content); | ||
|  | 		} catch (e) { | ||
|  | 			e.path = packagePath; | ||
|  | 			e.message = 'Error parsing ' + packagePath + ': ' + e.message; | ||
|  | 			throw e; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		const filtered = { | ||
|  | 			name: parsed.name, | ||
|  | 			main: parsed.main, | ||
|  | 			exports: parsed.exports, | ||
|  | 			imports: parsed.imports, | ||
|  | 			type: parsed.type | ||
|  | 		}; | ||
|  | 		this.packageCache[packagePath] = filtered; | ||
|  | 		return filtered; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	readPackageScope(path) { | ||
|  | 		while (true) { | ||
|  | 			const dir = this.pathDirname(path); | ||
|  | 			if (dir === path) break; | ||
|  | 			const basename = this.pathBasename(dir); | ||
|  | 			if (basename === 'node_modules') break; | ||
|  | 			const pack = this.readPackage(dir); | ||
|  | 			if (pack) return {data: pack, scope: dir}; | ||
|  | 			path = dir; | ||
|  | 		} | ||
|  | 		return {data: undefined, scope: undefined}; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_AS_FILE(X)
 | ||
|  | 	loadAsFile(x, extList) { | ||
|  | 		// 1. If X is a file, load X as its file extension format. STOP
 | ||
|  | 		const f = this.tryFile(x); | ||
|  | 		if (f) return f; | ||
|  | 		// 2. If X.js is a file, load X.js as JavaScript text. STOP
 | ||
|  | 		// 3. If X.json is a file, parse X.json to a JavaScript Object. STOP
 | ||
|  | 		// 4. If X.node is a file, load X.node as binary addon. STOP
 | ||
|  | 		return this.tryWithExtension(x, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_INDEX(X)
 | ||
|  | 	loadIndex(x, extList) { | ||
|  | 		// 1. If X/index.js is a file, load X/index.js as JavaScript text. STOP
 | ||
|  | 		// 2. If X/index.json is a file, parse X/index.json to a JavaScript object. STOP
 | ||
|  | 		// 3. If X/index.node is a file, load X/index.node as binary addon. STOP
 | ||
|  | 		return this.tryWithExtension(this.pathConcat(x, 'index'), extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_AS_DIRECTORY(X)
 | ||
|  | 	loadAsPackage(x, pack, extList) { | ||
|  | 		// 1. If X/package.json is a file,
 | ||
|  | 		// already done.
 | ||
|  | 		if (pack) { | ||
|  | 			// a. Parse X/package.json, and look for "main" field.
 | ||
|  | 			// b. If "main" is a falsy value, GOTO 2.
 | ||
|  | 			if (typeof pack.main === 'string') { | ||
|  | 				// c. let M = X + (json main field)
 | ||
|  | 				const m = this.pathConcat(x, pack.main); | ||
|  | 				// d. LOAD_AS_FILE(M)
 | ||
|  | 				let f = this.loadAsFile(m, extList); | ||
|  | 				if (f) return f; | ||
|  | 				// e. LOAD_INDEX(M)
 | ||
|  | 				f = this.loadIndex(m, extList); | ||
|  | 				if (f) return f; | ||
|  | 				// f. LOAD_INDEX(X) DEPRECATED
 | ||
|  | 				f = this.loadIndex(x, extList); | ||
|  | 				if (f) return f; | ||
|  | 				// g. THROW "not found"
 | ||
|  | 				throw new VMError(`Cannot find module '${x}'`, 'ENOTFOUND'); | ||
|  | 			} | ||
|  | 		} | ||
|  | 
 | ||
|  | 		// 2. LOAD_INDEX(X)
 | ||
|  | 		return this.loadIndex(x, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_AS_DIRECTORY(X)
 | ||
|  | 	loadAsDirectory(x, extList) { | ||
|  | 		// 1. If X/package.json is a file,
 | ||
|  | 		const pack = this.readPackage(x); | ||
|  | 		return this.loadAsPackage(x, pack, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_NODE_MODULES(X, START)
 | ||
|  | 	loadNodeModules(x, dirs, extList) { | ||
|  | 		// 1. let DIRS = NODE_MODULES_PATHS(START)
 | ||
|  | 		// This step is already done.
 | ||
|  | 
 | ||
|  | 		// 2. for each DIR in DIRS:
 | ||
|  | 		for (let i = 0; i < dirs.length; i++) { | ||
|  | 			const dir = dirs[i]; | ||
|  | 			// a. LOAD_PACKAGE_EXPORTS(X, DIR)
 | ||
|  | 			let f = this.loadPackageExports(x, dir, extList); | ||
|  | 			if (f) return f; | ||
|  | 			// b. LOAD_AS_FILE(DIR/X)
 | ||
|  | 			f = this.loadAsFile(dir + '/' + x, extList); | ||
|  | 			if (f) return f; | ||
|  | 			// c. LOAD_AS_DIRECTORY(DIR/X)
 | ||
|  | 			f = this.loadAsDirectory(dir + '/' + x, extList); | ||
|  | 			if (f) return f; | ||
|  | 		} | ||
|  | 
 | ||
|  | 		return undefined; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_PACKAGE_IMPORTS(X, DIR)
 | ||
|  | 	loadPackageImports(x, dir, extList) { | ||
|  | 		// 1. Find the closest package scope SCOPE to DIR.
 | ||
|  | 		const {data, scope} = this.readPackageScope(dir); | ||
|  | 		// 2. If no scope was found, return.
 | ||
|  | 		if (!data) return undefined; | ||
|  | 		// 3. If the SCOPE/package.json "imports" is null or undefined, return.
 | ||
|  | 		if (typeof data.imports !== 'object' || data.imports === null || Array.isArray(data.imports)) return undefined; | ||
|  | 		// 4. let MATCH = PACKAGE_IMPORTS_RESOLVE(X, pathToFileURL(SCOPE),
 | ||
|  | 		//   ["node", "require"]) defined in the ESM resolver.
 | ||
|  | 
 | ||
|  | 		// PACKAGE_IMPORTS_RESOLVE(specifier, parentURL, conditions)
 | ||
|  | 		// 1. Assert: specifier begins with "#".
 | ||
|  | 		// 2. If specifier is exactly equal to "#" or starts with "#/", then
 | ||
|  | 		if (x === '#' || x.startsWith('#/')) { | ||
|  | 			// a. Throw an Invalid Module Specifier error.
 | ||
|  | 			throw new VMError(`Invalid module specifier '${x}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 		} | ||
|  | 		// 3. Let packageURL be the result of LOOKUP_PACKAGE_SCOPE(parentURL).
 | ||
|  | 		// Note: packageURL === parentURL === scope
 | ||
|  | 		// 4. If packageURL is not null, then
 | ||
|  | 		// Always true
 | ||
|  | 		// a. Let pjson be the result of READ_PACKAGE_JSON(packageURL).
 | ||
|  | 		// pjson === data
 | ||
|  | 		// b. If pjson.imports is a non-null Object, then
 | ||
|  | 		// Already tested
 | ||
|  | 		// x. Let resolved be the result of PACKAGE_IMPORTS_EXPORTS_RESOLVE( specifier, pjson.imports, packageURL, true, conditions).
 | ||
|  | 		const match = this.packageImportsExportsResolve(x, data.imports, scope, true, ['node', 'require'], extList); | ||
|  | 		// y. If resolved is not null or undefined, return resolved.
 | ||
|  | 		if (!match) { | ||
|  | 			// 5. Throw a Package Import Not Defined error.
 | ||
|  | 			throw new VMError(`Package import not defined for '${x}'`, 'ERR_PACKAGE_IMPORT_NOT_DEFINED'); | ||
|  | 		} | ||
|  | 		// END PACKAGE_IMPORTS_RESOLVE
 | ||
|  | 
 | ||
|  | 		// 5. RESOLVE_ESM_MATCH(MATCH).
 | ||
|  | 		return this.resolveEsmMatch(match, x, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_PACKAGE_EXPORTS(X, DIR)
 | ||
|  | 	loadPackageExports(x, dir, extList) { | ||
|  | 		// 1. Try to interpret X as a combination of NAME and SUBPATH where the name
 | ||
|  | 		//    may have a @scope/ prefix and the subpath begins with a slash (`/`).
 | ||
|  | 		const res = x.match(EXPORTS_PATTERN); | ||
|  | 		// 2. If X does not match this pattern or DIR/NAME/package.json is not a file,
 | ||
|  | 		//    return.
 | ||
|  | 		if (!res) return undefined; | ||
|  | 		const scope = this.pathConcat(dir, res[1]); | ||
|  | 		const pack = this.readPackage(scope); | ||
|  | 		if (!pack) return undefined; | ||
|  | 		// 3. Parse DIR/NAME/package.json, and look for "exports" field.
 | ||
|  | 		// 4. If "exports" is null or undefined, return.
 | ||
|  | 		if (!pack.exports) return undefined; | ||
|  | 		// 5. let MATCH = PACKAGE_EXPORTS_RESOLVE(pathToFileURL(DIR/NAME), "." + SUBPATH,
 | ||
|  | 		//    `package.json` "exports", ["node", "require"]) defined in the ESM resolver.
 | ||
|  | 		const match = this.packageExportsResolve(scope, '.' + (res[2] || ''), pack.exports, ['node', 'require'], extList); | ||
|  | 		// 6. RESOLVE_ESM_MATCH(MATCH)
 | ||
|  | 		return this.resolveEsmMatch(match, x, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// LOAD_PACKAGE_SELF(X, DIR)
 | ||
|  | 	loadPackageSelf(x, dir, extList) { | ||
|  | 		// 1. Find the closest package scope SCOPE to DIR.
 | ||
|  | 		const {data, scope} = this.readPackageScope(dir); | ||
|  | 		// 2. If no scope was found, return.
 | ||
|  | 		if (!data) return undefined; | ||
|  | 		// 3. If the SCOPE/package.json "exports" is null or undefined, return.
 | ||
|  | 		if (!data.exports) return undefined; | ||
|  | 		// 4. If the SCOPE/package.json "name" is not the first segment of X, return.
 | ||
|  | 		if (x !== data.name && !x.startsWith(data.name + '/')) return undefined; | ||
|  | 		// 5. let MATCH = PACKAGE_EXPORTS_RESOLVE(pathToFileURL(SCOPE),
 | ||
|  | 		//    "." + X.slice("name".length), `package.json` "exports", ["node", "require"])
 | ||
|  | 		//    defined in the ESM resolver.
 | ||
|  | 		const match = this.packageExportsResolve(scope, '.' + x.slice(data.name.length), data.exports, ['node', 'require'], extList); | ||
|  | 		// 6. RESOLVE_ESM_MATCH(MATCH)
 | ||
|  | 		return this.resolveEsmMatch(match, x, extList); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// RESOLVE_ESM_MATCH(MATCH)
 | ||
|  | 	resolveEsmMatch(match, x, extList) { | ||
|  | 		// 1. let { RESOLVED, EXACT } = MATCH
 | ||
|  | 		const resolved = match; | ||
|  | 		const exact = true; | ||
|  | 		// 2. let RESOLVED_PATH = fileURLToPath(RESOLVED)
 | ||
|  | 		const resolvedPath = resolved; | ||
|  | 		let f; | ||
|  | 		// 3. If EXACT is true,
 | ||
|  | 		if (exact) { | ||
|  | 			// a. If the file at RESOLVED_PATH exists, load RESOLVED_PATH as its extension
 | ||
|  | 			// format. STOP
 | ||
|  | 			f = this.tryFile(resolvedPath); | ||
|  | 		// 4. Otherwise, if EXACT is false,
 | ||
|  | 		} else { | ||
|  | 			// a. LOAD_AS_FILE(RESOLVED_PATH)
 | ||
|  | 			// b. LOAD_AS_DIRECTORY(RESOLVED_PATH)
 | ||
|  | 			f = this.loadAsFileOrDirecotry(resolvedPath, extList); | ||
|  | 		} | ||
|  | 		if (f) return f; | ||
|  | 		// 5. THROW "not found"
 | ||
|  | 		throw new VMError(`Cannot find module '${x}'`, 'ENOTFOUND'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// PACKAGE_EXPORTS_RESOLVE(packageURL, subpath, exports, conditions)
 | ||
|  | 	packageExportsResolve(packageURL, subpath, rexports, conditions, extList) { | ||
|  | 		// 1. If exports is an Object with both a key starting with "." and a key not starting with ".", throw an Invalid Package Configuration error.
 | ||
|  | 		let hasDots = false; | ||
|  | 		if (typeof rexports === 'object' && !Array.isArray(rexports)) { | ||
|  | 			const keys = Object.getOwnPropertyNames(rexports); | ||
|  | 			if (keys.length > 0) { | ||
|  | 				hasDots = keys[0][0] === '.'; | ||
|  | 				for (let i = 0; i < keys.length; i++) { | ||
|  | 					if (hasDots !== (keys[i][0] === '.')) { | ||
|  | 						throw new VMError('Invalid package configuration', 'ERR_INVALID_PACKAGE_CONFIGURATION'); | ||
|  | 					} | ||
|  | 				} | ||
|  | 			} | ||
|  | 		} | ||
|  | 		// 2. If subpath is equal to ".", then
 | ||
|  | 		if (subpath === '.') { | ||
|  | 			// a. Let mainExport be undefined.
 | ||
|  | 			let mainExport = undefined; | ||
|  | 			// b. If exports is a String or Array, or an Object containing no keys starting with ".", then
 | ||
|  | 			if (typeof rexports === 'string' || Array.isArray(rexports) || !hasDots) { | ||
|  | 				// x. Set mainExport to exports.
 | ||
|  | 				mainExport = rexports; | ||
|  | 			// c. Otherwise if exports is an Object containing a "." property, then
 | ||
|  | 			} else if (hasDots) { | ||
|  | 				// x. Set mainExport to exports["."].
 | ||
|  | 				mainExport = rexports['.']; | ||
|  | 			} | ||
|  | 			// d. If mainExport is not undefined, then
 | ||
|  | 			if (mainExport) { | ||
|  | 				// x. Let resolved be the result of PACKAGE_TARGET_RESOLVE( packageURL, mainExport, "", false, false, conditions).
 | ||
|  | 				const resolved = this.packageTargetResolve(packageURL, mainExport, '', false, false, conditions, extList); | ||
|  | 				// y. If resolved is not null or undefined, return resolved.
 | ||
|  | 				if (resolved) return resolved; | ||
|  | 			} | ||
|  | 		// 3. Otherwise, if exports is an Object and all keys of exports start with ".", then
 | ||
|  | 		} else if (hasDots) { | ||
|  | 			// a. Let matchKey be the string "./" concatenated with subpath.
 | ||
|  | 			// Note: Here subpath starts already with './'
 | ||
|  | 			// b. Let resolved be the result of PACKAGE_IMPORTS_EXPORTS_RESOLVE( matchKey, exports, packageURL, false, conditions).
 | ||
|  | 			const resolved = this.packageImportsExportsResolve(subpath, rexports, packageURL, false, conditions, extList); | ||
|  | 			// c. If resolved is not null or undefined, return resolved.
 | ||
|  | 			if (resolved) return resolved; | ||
|  | 		} | ||
|  | 		// 4. Throw a Package Path Not Exported error.
 | ||
|  | 		throw new VMError(`Package path '${subpath}' is not exported`, 'ERR_PACKAGE_PATH_NOT_EXPORTED'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// PACKAGE_IMPORTS_EXPORTS_RESOLVE(matchKey, matchObj, packageURL, isImports, conditions)
 | ||
|  | 	packageImportsExportsResolve(matchKey, matchObj, packageURL, isImports, conditions, extList) { | ||
|  | 		// 1. If matchKey is a key of matchObj and does not contain "*", then
 | ||
|  | 		let target = matchObj[matchKey]; | ||
|  | 		if (target && matchKey.indexOf('*') === -1) { | ||
|  | 			// a. Let target be the value of matchObj[matchKey].
 | ||
|  | 			// b. Return the result of PACKAGE_TARGET_RESOLVE(packageURL, target, "", false, isImports, conditions).
 | ||
|  | 			return this.packageTargetResolve(packageURL, target, '', false, isImports, conditions, extList); | ||
|  | 		} | ||
|  | 		// 2. Let expansionKeys be the list of keys of matchObj containing only a single "*",
 | ||
|  | 		//    sorted by the sorting function PATTERN_KEY_COMPARE which orders in descending order of specificity.
 | ||
|  | 		const expansionKeys = Object.getOwnPropertyNames(matchObj); | ||
|  | 		let bestKey = ''; | ||
|  | 		let bestSubpath; | ||
|  | 		// 3. For each key expansionKey in expansionKeys, do
 | ||
|  | 		for (let i = 0; i < expansionKeys.length; i++) { | ||
|  | 			const expansionKey = expansionKeys[i]; | ||
|  | 			if (matchKey.length < expansionKey.length) continue; | ||
|  | 			// a. Let patternBase be the substring of expansionKey up to but excluding the first "*" character.
 | ||
|  | 			const star = expansionKey.indexOf('*'); | ||
|  | 			if (star === -1) continue; // Note: expansionKeys was not filtered
 | ||
|  | 			const patternBase = expansionKey.slice(0, star); | ||
|  | 			// b. If matchKey starts with but is not equal to patternBase, then
 | ||
|  | 			if (matchKey.startsWith(patternBase) && expansionKey.indexOf('*', star + 1) === -1) { // Note: expansionKeys was not filtered
 | ||
|  | 				// 1. Let patternTrailer be the substring of expansionKey from the index after the first "*" character.
 | ||
|  | 				const patternTrailer = expansionKey.slice(star + 1); | ||
|  | 				// 2. If patternTrailer has zero length, or if matchKey ends with patternTrailer and the length of matchKey is greater than or
 | ||
|  | 				//    equal to the length of expansionKey, then
 | ||
|  | 				if (matchKey.endsWith(patternTrailer) && this.patternKeyCompare(bestKey, expansionKey) === 1) { // Note: expansionKeys was not sorted
 | ||
|  | 					// a. Let target be the value of matchObj[expansionKey].
 | ||
|  | 					target = matchObj[expansionKey]; | ||
|  | 					// b. Let subpath be the substring of matchKey starting at the index of the length of patternBase up to the length of
 | ||
|  | 					//    matchKey minus the length of patternTrailer.
 | ||
|  | 					bestKey = expansionKey; | ||
|  | 					bestSubpath = matchKey.slice(patternBase.length, matchKey.length - patternTrailer.length); | ||
|  | 				} | ||
|  | 			} | ||
|  | 		} | ||
|  | 		if (bestSubpath) { // Note: expansionKeys was not sorted
 | ||
|  | 			// c. Return the result of PACKAGE_TARGET_RESOLVE(packageURL, target, subpath, true, isImports, conditions).
 | ||
|  | 			return this.packageTargetResolve(packageURL, target, bestSubpath, true, isImports, conditions, extList); | ||
|  | 		} | ||
|  | 		// 4. Return null.
 | ||
|  | 		return null; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// PATTERN_KEY_COMPARE(keyA, keyB)
 | ||
|  | 	patternKeyCompare(keyA, keyB) { | ||
|  | 		// 1. Assert: keyA ends with "/" or contains only a single "*".
 | ||
|  | 		// 2. Assert: keyB ends with "/" or contains only a single "*".
 | ||
|  | 		// 3. Let baseLengthA be the index of "*" in keyA plus one, if keyA contains "*", or the length of keyA otherwise.
 | ||
|  | 		const baseAStar = keyA.indexOf('*'); | ||
|  | 		const baseLengthA = baseAStar === -1 ? keyA.length : baseAStar + 1; | ||
|  | 		// 4. Let baseLengthB be the index of "*" in keyB plus one, if keyB contains "*", or the length of keyB otherwise.
 | ||
|  | 		const baseBStar = keyB.indexOf('*'); | ||
|  | 		const baseLengthB = baseBStar === -1 ? keyB.length : baseBStar + 1; | ||
|  | 		// 5. If baseLengthA is greater than baseLengthB, return -1.
 | ||
|  | 		if (baseLengthA > baseLengthB) return -1; | ||
|  | 		// 6. If baseLengthB is greater than baseLengthA, return 1.
 | ||
|  | 		if (baseLengthB > baseLengthA) return 1; | ||
|  | 		// 7. If keyA does not contain "*", return 1.
 | ||
|  | 		if (baseAStar === -1) return 1; | ||
|  | 		// 8. If keyB does not contain "*", return -1.
 | ||
|  | 		if (baseBStar === -1) return -1; | ||
|  | 		// 9. If the length of keyA is greater than the length of keyB, return -1.
 | ||
|  | 		if (keyA.length > keyB.length) return -1; | ||
|  | 		// 10. If the length of keyB is greater than the length of keyA, return 1.
 | ||
|  | 		if (keyB.length > keyA.length) return 1; | ||
|  | 		// 11. Return 0.
 | ||
|  | 		return 0; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// PACKAGE_TARGET_RESOLVE(packageURL, target, subpath, pattern, internal, conditions)
 | ||
|  | 	packageTargetResolve(packageURL, target, subpath, pattern, internal, conditions, extList) { | ||
|  | 		// 1. If target is a String, then
 | ||
|  | 		if (typeof target === 'string') { | ||
|  | 			// a. If pattern is false, subpath has non-zero length and target does not end with "/", throw an Invalid Module Specifier error.
 | ||
|  | 			if (!pattern && subpath.length > 0 && !target.endsWith('/')) { | ||
|  | 				throw new VMError(`Invalid package specifier '${subpath}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 			} | ||
|  | 			// b. If target does not start with "./", then
 | ||
|  | 			if (!target.startsWith('./')) { | ||
|  | 				// 1. If internal is true and target does not start with "../" or "/" and is not a valid URL, then
 | ||
|  | 				if (internal && !target.startsWith('../') && !target.startsWith('/')) { | ||
|  | 					let isURL = false; | ||
|  | 					try { | ||
|  | 						// eslint-disable-next-line no-new
 | ||
|  | 						new URL(target); | ||
|  | 						isURL = true; | ||
|  | 					} catch (e) {} | ||
|  | 					if (!isURL) { | ||
|  | 						// a. If pattern is true, then
 | ||
|  | 						if (pattern) { | ||
|  | 							// 1. Return PACKAGE_RESOLVE(target with every instance of "*" replaced by subpath, packageURL + "/").
 | ||
|  | 							return this.packageResolve(target.replace(/\*/g, subpath), packageURL, conditions, extList); | ||
|  | 						} | ||
|  | 						// b. Return PACKAGE_RESOLVE(target + subpath, packageURL + "/").
 | ||
|  | 						return this.packageResolve(this.pathConcat(target, subpath), packageURL, conditions, extList); | ||
|  | 					} | ||
|  | 				} | ||
|  | 				// Otherwise, throw an Invalid Package Target error.
 | ||
|  | 				throw new VMError(`Invalid package target for '${subpath}'`, 'ERR_INVALID_PACKAGE_TARGET'); | ||
|  | 			} | ||
|  | 			target = decodeURI(target); | ||
|  | 			// c. If target split on "/" or "\" contains any ".", ".." or "node_modules" segments after the first segment, case insensitive
 | ||
|  | 			//    and including percent encoded variants, throw an Invalid Package Target error.
 | ||
|  | 			if (target.split(/[/\\]/).slice(1).findIndex(x => x === '.' || x === '..' || x.toLowerCase() === 'node_modules') !== -1) { | ||
|  | 				throw new VMError(`Invalid package target for '${subpath}'`, 'ERR_INVALID_PACKAGE_TARGET'); | ||
|  | 			} | ||
|  | 			// d. Let resolvedTarget be the URL resolution of the concatenation of packageURL and target.
 | ||
|  | 			const resolvedTarget = this.pathConcat(packageURL, target); | ||
|  | 			// e. Assert: resolvedTarget is contained in packageURL.
 | ||
|  | 			subpath = decodeURI(subpath); | ||
|  | 			// f. If subpath split on "/" or "\" contains any ".", ".." or "node_modules" segments, case insensitive and including percent
 | ||
|  | 			//    encoded variants, throw an Invalid Module Specifier error.
 | ||
|  | 			if (subpath.split(/[/\\]/).findIndex(x => x === '.' || x === '..' || x.toLowerCase() === 'node_modules') !== -1) { | ||
|  | 				throw new VMError(`Invalid package specifier '${subpath}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 			} | ||
|  | 			// g. If pattern is true, then
 | ||
|  | 			if (pattern) { | ||
|  | 				// 1. Return the URL resolution of resolvedTarget with every instance of "*" replaced with subpath.
 | ||
|  | 				return resolvedTarget.replace(/\*/g, subpath); | ||
|  | 			} | ||
|  | 			// h. Otherwise,
 | ||
|  | 			// 1. Return the URL resolution of the concatenation of subpath and resolvedTarget.
 | ||
|  | 			return this.pathConcat(resolvedTarget, subpath); | ||
|  | 		// 3. Otherwise, if target is an Array, then
 | ||
|  | 		} else if (Array.isArray(target)) { | ||
|  | 			// a. If target.length is zero, return null.
 | ||
|  | 			if (target.length === 0) return null; | ||
|  | 			let lastException = undefined; | ||
|  | 			// b. For each item targetValue in target, do
 | ||
|  | 			for (let i = 0; i < target.length; i++) { | ||
|  | 				const targetValue = target[i]; | ||
|  | 				// 1. Let resolved be the result of PACKAGE_TARGET_RESOLVE( packageURL, targetValue, subpath, pattern, internal, conditions),
 | ||
|  | 				//    continuing the loop on any Invalid Package Target error.
 | ||
|  | 				let resolved; | ||
|  | 				try { | ||
|  | 					resolved = this.packageTargetResolve(packageURL, targetValue, subpath, pattern, internal, conditions, extList); | ||
|  | 				} catch (e) { | ||
|  | 					if (e.code !== 'ERR_INVALID_PACKAGE_TARGET') throw e; | ||
|  | 					lastException = e; | ||
|  | 					continue; | ||
|  | 				} | ||
|  | 				// 2. If resolved is undefined, continue the loop.
 | ||
|  | 				// 3. Return resolved.
 | ||
|  | 				if (resolved !== undefined) return resolved; | ||
|  | 				if (resolved === null) { | ||
|  | 					lastException = null; | ||
|  | 				} | ||
|  | 			} | ||
|  | 			// c. Return or throw the last fallback resolution null return or error.
 | ||
|  | 			if (lastException === undefined || lastException === null) return lastException; | ||
|  | 			throw lastException; | ||
|  | 		// 2. Otherwise, if target is a non-null Object, then
 | ||
|  | 		} else if (typeof target === 'object' && target !== null) { | ||
|  | 			const keys = Object.getOwnPropertyNames(target); | ||
|  | 			// a. If exports contains any index property keys, as defined in ECMA-262 6.1.7 Array Index, throw an Invalid Package Configuration error.
 | ||
|  | 			for (let i = 0; i < keys.length; i++) { | ||
|  | 				const p = keys[i]; | ||
|  | 				if (isArrayIndex(p)) throw new VMError(`Invalid package configuration for '${subpath}'`, 'ERR_INVALID_PACKAGE_CONFIGURATION'); | ||
|  | 			} | ||
|  | 			// b. For each property p of target, in object insertion order as,
 | ||
|  | 			for (let i = 0; i < keys.length; i++) { | ||
|  | 				const p = keys[i]; | ||
|  | 				// 1. If p equals "default" or conditions contains an entry for p, then
 | ||
|  | 				if (p === 'default' || conditions.includes(p)) { | ||
|  | 					// a. Let targetValue be the value of the p property in target.
 | ||
|  | 					const targetValue = target[p]; | ||
|  | 					// b. Let resolved be the result of PACKAGE_TARGET_RESOLVE( packageURL, targetValue, subpath, pattern, internal, conditions).
 | ||
|  | 					const resolved = this.packageTargetResolve(packageURL, targetValue, subpath, pattern, internal, conditions, extList); | ||
|  | 					// c. If resolved is equal to undefined, continue the loop.
 | ||
|  | 					// d. Return resolved.
 | ||
|  | 					if (resolved !== undefined) return resolved; | ||
|  | 				} | ||
|  | 			} | ||
|  | 			// c. Return undefined.
 | ||
|  | 			return undefined; | ||
|  | 		// 4. Otherwise, if target is null, return null.
 | ||
|  | 		} else if (target == null) { | ||
|  | 			return null; | ||
|  | 		} | ||
|  | 		// Otherwise throw an Invalid Package Target error.
 | ||
|  | 		throw new VMError(`Invalid package target for '${subpath}'`, 'ERR_INVALID_PACKAGE_TARGET'); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	// PACKAGE_RESOLVE(packageSpecifier, parentURL)
 | ||
|  | 	packageResolve(packageSpecifier, parentURL, conditions, extList) { | ||
|  | 		// 1. Let packageName be undefined.
 | ||
|  | 		let packageName = undefined; | ||
|  | 		// 2. If packageSpecifier is an empty string, then
 | ||
|  | 		if (packageSpecifier === '') { | ||
|  | 			// a. Throw an Invalid Module Specifier error.
 | ||
|  | 			throw new VMError(`Invalid package specifier '${packageSpecifier}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 		} | ||
|  | 		// 3. If packageSpecifier is a Node.js builtin module name, then
 | ||
|  | 		if (this.builtinModules[packageSpecifier]) { | ||
|  | 			// a. Return the string "node:" concatenated with packageSpecifier.
 | ||
|  | 			return 'node:' + packageSpecifier; | ||
|  | 		} | ||
|  | 		let idx = packageSpecifier.indexOf('/'); | ||
|  | 		// 5. Otherwise,
 | ||
|  | 		if (packageSpecifier[0] === '@') { | ||
|  | 			// a. If packageSpecifier does not contain a "/" separator, then
 | ||
|  | 			if (idx === -1) { | ||
|  | 				// x. Throw an Invalid Module Specifier error.
 | ||
|  | 				throw new VMError(`Invalid package specifier '${packageSpecifier}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 			} | ||
|  | 			// b. Set packageName to the substring of packageSpecifier until the second "/" separator or the end of the string.
 | ||
|  | 			idx = packageSpecifier.indexOf('/', idx + 1); | ||
|  | 		} | ||
|  | 		// else
 | ||
|  | 		// 4. If packageSpecifier does not start with "@", then
 | ||
|  | 		// a. Set packageName to the substring of packageSpecifier until the first "/" separator or the end of the string.
 | ||
|  | 		packageName = idx === -1 ? packageSpecifier : packageSpecifier.slice(0, idx); | ||
|  | 		// 6. If packageName starts with "." or contains "\" or "%", then
 | ||
|  | 		if (idx !== 0 && (packageName[0] === '.' || packageName.indexOf('\\') >= 0 || packageName.indexOf('%') >= 0)) { | ||
|  | 			// a. Throw an Invalid Module Specifier error.
 | ||
|  | 			throw new VMError(`Invalid package specifier '${packageSpecifier}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 		} | ||
|  | 		// 7. Let packageSubpath be "." concatenated with the substring of packageSpecifier from the position at the length of packageName.
 | ||
|  | 		const packageSubpath = '.' + packageSpecifier.slice(packageName.length); | ||
|  | 		// 8. If packageSubpath ends in "/", then
 | ||
|  | 		if (packageSubpath[packageSubpath.length - 1] === '/') { | ||
|  | 			// a. Throw an Invalid Module Specifier error.
 | ||
|  | 			throw new VMError(`Invalid package specifier '${packageSpecifier}'`, 'ERR_INVALID_MODULE_SPECIFIER'); | ||
|  | 		} | ||
|  | 		// 9. Let selfUrl be the result of PACKAGE_SELF_RESOLVE(packageName, packageSubpath, parentURL).
 | ||
|  | 		const selfUrl = this.packageSelfResolve(packageName, packageSubpath, parentURL); | ||
|  | 		// 10. If selfUrl is not undefined, return selfUrl.
 | ||
|  | 		if (selfUrl) return selfUrl; | ||
|  | 		// 11. While parentURL is not the file system root,
 | ||
|  | 		let packageURL; | ||
|  | 		while (true) { | ||
|  | 			// a. Let packageURL be the URL resolution of "node_modules/" concatenated with packageSpecifier, relative to parentURL.
 | ||
|  | 			packageURL = this.pathResolve(this.pathConcat(parentURL, 'node_modules', packageSpecifier)); | ||
|  | 			// b. Set parentURL to the parent folder URL of parentURL.
 | ||
|  | 			const parentParentURL = this.pathDirname(parentURL); | ||
|  | 			// c. If the folder at packageURL does not exist, then
 | ||
|  | 			if (this.isPathAllowed(packageURL) && this.pathTestIsDirectory(packageURL)) break; | ||
|  | 			// 1. Continue the next loop iteration.
 | ||
|  | 			if (parentParentURL === parentURL) { | ||
|  | 				// 12. Throw a Module Not Found error.
 | ||
|  | 				throw new VMError(`Cannot find module '${packageSpecifier}'`, 'ENOTFOUND'); | ||
|  | 			} | ||
|  | 			parentURL = parentParentURL; | ||
|  | 		} | ||
|  | 		// d. Let pjson be the result of READ_PACKAGE_JSON(packageURL).
 | ||
|  | 		const pack = this.readPackage(packageURL); | ||
|  | 		// e. If pjson is not null and pjson.exports is not null or undefined, then
 | ||
|  | 		if (pack && pack.exports) { | ||
|  | 			// 1. Return the result of PACKAGE_EXPORTS_RESOLVE(packageURL, packageSubpath, pjson.exports, defaultConditions).
 | ||
|  | 			return this.packageExportsResolve(packageURL, packageSubpath, pack.exports, conditions, extList); | ||
|  | 		} | ||
|  | 		// f. Otherwise, if packageSubpath is equal to ".", then
 | ||
|  | 		if (packageSubpath === '.') { | ||
|  | 			// 1. If pjson.main is a string, then
 | ||
|  | 			// a. Return the URL resolution of main in packageURL.
 | ||
|  | 			return this.loadAsPackage(packageSubpath, pack, extList); | ||
|  | 		} | ||
|  | 		// g. Otherwise,
 | ||
|  | 		// 1. Return the URL resolution of packageSubpath in packageURL.
 | ||
|  | 		return this.pathConcat(packageURL, packageSubpath); | ||
|  | 	} | ||
|  | 
 | ||
|  | } | ||
|  | 
 | ||
|  | exports.Resolver = Resolver; | ||
|  | exports.DefaultResolver = DefaultResolver; |