unpkg/server/plugins/unpkgRewrite.js

49 lines
1.4 KiB
JavaScript

const URL = require("whatwg-url");
const warning = require("warning");
const config = require("../config");
const bareIdentifierFormat = /^((?:@[^/]+\/)?[^/]+)(\/.*)?$/;
function unpkgRewrite(dependencies = {}) {
return {
inherits: require("babel-plugin-syntax-export-extensions"),
visitor: {
"ImportDeclaration|ExportNamedDeclaration|ExportAllDeclaration"(path) {
if (!path.node.source) return; // probably a variable declaration
if (
URL.parseURL(path.node.source.value) != null ||
path.node.source.value.substr(0, 2) === "//"
)
return; // valid URL or URL w/o protocol, leave it alone
if ([".", "/"].indexOf(path.node.source.value.charAt(0)) >= 0) {
// local path
path.node.source.value = `${path.node.source.value}?module`;
} else {
// "bare" identifier
const match = bareIdentifierFormat.exec(path.node.source.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";
path.node.source.value = `${
config.origin
}/${packageName}@${version}${file}?module`;
}
}
}
};
}
module.exports = unpkgRewrite;