unpkg/modules/plugins/unpkgRewrite.js

93 lines
2.3 KiB
JavaScript

const URL = require('whatwg-url');
const warning = require('warning');
const origin = require('../serverConfig').origin;
const bareIdentifierFormat = /^((?:@[^/]+\/)?[^/]+)(\/.*)?$/;
function isValidURL(value) {
return URL.parseURL(value) != null;
}
function isProbablyURLWithoutProtocol(value) {
return value.substr(0, 2) === '//';
}
function isAbsoluteURL(value) {
return isValidURL(value) || isProbablyURLWithoutProtocol(value);
}
function isBareIdentifier(value) {
return value.charAt(0) !== '.' && value.charAt(0) !== '/';
}
function rewriteValue(/* StringLiteral */ node, dependencies) {
if (isAbsoluteURL(node.value)) {
return;
}
if (isBareIdentifier(node.value)) {
// "bare" identifier
const match = bareIdentifierFormat.exec(node.value);
const packageName = match[1];
const file = match[2] || '';
warning(
dependencies[packageName],
'Missing version info for package "%s" in dependencies; falling back to "latest"',
packageName
);
const version = dependencies[packageName] || 'latest';
node.value = `${origin}/${packageName}@${version}${file}?module`;
} else {
// local path
node.value = `${node.value}?module`;
}
}
function unpkgRewrite(dependencies = {}) {
return {
manipulateOptions(opts, parserOpts) {
parserOpts.plugins.push(
'dynamicImport',
'exportDefaultFrom',
'exportNamespaceFrom',
'importMeta'
);
},
visitor: {
CallExpression(path) {
if (path.node.callee.type !== 'Import') {
// Some other function call, not import();
return;
}
rewriteValue(path.node.arguments[0], dependencies);
},
ExportAllDeclaration(path) {
return rewriteValue(path.node.source, dependencies);
},
ExportNamedDeclaration(path) {
if (!path.node.source) {
// This export has no "source", so it's probably
// a local variable or function, e.g.
// export { varName }
// export const constName = ...
// export function funcName() {}
return;
}
rewriteValue(path.node.source, dependencies);
},
ImportDeclaration(path) {
return rewriteValue(path.node.source, dependencies);
}
}
};
}
module.exports = unpkgRewrite;