forked from nodejs/node
/
get_format.js
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get_format.js
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'use strict';
const { NativeModule } = require('internal/bootstrap/loaders');
const { extname } = require('path');
const { getOptionValue } = require('internal/options');
const experimentalJsonModules = getOptionValue('--experimental-json-modules');
const experimentalSpeciferResolution =
getOptionValue('--experimental-specifier-resolution');
const experimentalWasmModules = getOptionValue('--experimental-wasm-modules');
const { getPackageType } = internalBinding('module_wrap');
const { URL, fileURLToPath } = require('internal/url');
const { ERR_UNKNOWN_FILE_EXTENSION } = require('internal/errors').codes;
// const TYPE_NONE = 0;
// const TYPE_COMMONJS = 1;
const TYPE_MODULE = 2;
const extensionFormatMap = {
'__proto__': null,
'.cjs': 'commonjs',
'.js': 'module',
'.mjs': 'module'
};
const legacyExtensionFormatMap = {
'__proto__': null,
'.cjs': 'commonjs',
'.js': 'commonjs',
'.json': 'commonjs',
'.mjs': 'module',
'.node': 'commonjs'
};
if (experimentalWasmModules)
extensionFormatMap['.wasm'] = legacyExtensionFormatMap['.wasm'] = 'wasm';
if (experimentalJsonModules)
extensionFormatMap['.json'] = legacyExtensionFormatMap['.json'] = 'json';
function defaultGetFormat(url, context, defaultGetFormat) {
if (NativeModule.canBeRequiredByUsers(url)) {
return { format: 'builtin' };
}
const parsed = new URL(url);
if (parsed.protocol === 'data:') {
const [ , mime ] = /^([^/]+\/[^;,]+)(?:[^,]*?)(;base64)?,/.exec(parsed.pathname) || [ null, null, null ];
const format = ({
'__proto__': null,
'text/javascript': 'module',
'application/json': experimentalJsonModules ? 'json' : null,
'application/wasm': experimentalWasmModules ? 'wasm' : null
})[mime] || null;
return { format };
} else if (parsed.protocol === 'file:') {
const ext = extname(parsed.pathname);
let format = extensionFormatMap[ext];
const isMain = context.parentURL === undefined;
if (ext === '.js' || (!format && isMain))
format = getPackageType(parsed.href) === TYPE_MODULE ?
'module' : 'commonjs';
if (!format) {
if (experimentalSpeciferResolution === 'node') {
process.emitWarning(
'The Node.js specifier resolution in ESM is experimental.',
'ExperimentalWarning');
format = legacyExtensionFormatMap[ext];
} else {
throw new ERR_UNKNOWN_FILE_EXTENSION(ext, fileURLToPath(url));
}
}
return { format: format || null };
}
}
exports.defaultGetFormat = defaultGetFormat;