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/** | |
* @file Userland JS implementation of Node.js's specifier restriction. | |
* @flag --experimental-loader | |
* @license 0BSD | |
* @author Derek Lewis <DerekNonGeneric@inf.is> | |
* @module {Es6Module} reservedResolve_userland | |
* @see https://github.com/nodejs/modules/issues/505 | |
*/ | |
import { inspect } from 'util'; | |
const baseURL = new URL('file://'); | |
baseURL.pathname = process.cwd() + '/'; | |
// ----------------------------------------------------------------------------- | |
// Helpers | |
// ----------------------------------------------------------------------------- | |
/** | |
* If specifier starts with the character U+002F SOLIDUS (`/`) or the | |
* two-character sequence U+002F SOLIDUS U+002F SOLIDUS (`//`), return true. | |
* @param {string} specifier | |
* @returns {boolean} | |
* @see https://github.com/nodejs/node/blame/master/doc/api/esm.md#L825-L826 | |
*/ | |
export function isReservedSpecifier(specifier) { | |
if (specifier.charCodeAt(0) === 0x2f /* U+002F SOLIDUS (`/`) */) { | |
return true; | |
} else { | |
return false; | |
} | |
} | |
// ----------------------------------------------------------------------------- | |
// Errors | |
// ----------------------------------------------------------------------------- | |
/** | |
**ERR_INVALID_MODULE_SPECIFIER | |
* @description An invalid module specifier. | |
*/ | |
export class InvalidModuleSpecifierError extends TypeError { | |
/** | |
* @param {string} specifier The invalid module specifier. | |
* @param {string} baseFilePath The parent module's file path basename. | |
*/ | |
constructor(specifier, baseFilePath) { | |
super( | |
`Failed to resolve module specifier ${inspect(specifier)} imported ` + | |
`from ${inspect(baseFilePath)}. Specifiers may not begin with '/' ` + | |
"or '//'. These are reserved for potential future use." | |
); | |
this.code = 'ERR_INVALID_MODULE_SPECIFIER'; | |
} | |
} | |
// ----------------------------------------------------------------------------- | |
// Hooks | |
// ----------------------------------------------------------------------------- | |
/** | |
* Resolve hook that allows customizing the default module resolution. | |
* @param {string} specifier | |
* @param {{ | |
* conditions: Array<string>, | |
* parentURL: !(string | undefined), | |
* }} context | |
* @param {!Function} defaultResolve | |
* @returns {Promise<{ url: string }>} | |
*/ | |
export function resolve(specifier, context, defaultResolve) { | |
const { parentURL = baseURL.href } = context; | |
if (isReservedSpecifier(specifier)) { | |
throw new InvalidModuleSpecifierError(specifier, parentURL); | |
} else { | |
return defaultResolve(specifier, { parentURL }, defaultResolve); | |
} | |
} |
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