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/*
Author Tobias Koppers @sokra
*/
"use strict";
const { pathToFileURL } = require("url");
const LoaderLoadingError = require("../errors/LoaderLoadingError");
/** @typedef {import("./LoaderRunner").LoaderObject} LoaderObject */
/**
* Lazily-compiled dynamic `import()`. Built on first use so this file still
* parses on Node versions without native `import()` (<13.2), then reused.
* @type {((url: URL) => Promise<EXPECTED_ANY>) | undefined}
*/
let importModule;
/**
* @param {LoaderObject} loader the loader to load into
* @param {EXPECTED_ANY} module the loaded module
* @param {(err?: Error) => void} callback callback
* @returns {void}
*/
function handleResult(loader, module, callback) {
if (typeof module !== "function" && typeof module !== "object") {
return callback(
new LoaderLoadingError(
`Module '${loader.path}' is not a loader (export function or es6 module)`
)
);
}
loader.normal = typeof module === "function" ? module : module.default;
loader.pitch = module.pitch;
loader.raw = module.raw;
if (
typeof loader.normal !== "function" &&
typeof loader.pitch !== "function"
) {
return callback(
new LoaderLoadingError(
`Module '${loader.path}' is not a loader (must have normal or pitch function)`
)
);
}
callback();
}
/**
* @param {LoaderObject} loader the loader to load
* @param {(err?: Error) => void} callback callback
* @returns {void}
*/
function loadLoader(loader, callback) {
if (loader.type === "module") {
try {
if (importModule === undefined) {
// `eval` defers parsing `import()` to runtime, so this file stays
// loadable on Node versions that can't parse it (<13.2).
// eslint-disable-next-line no-eval
const dynamicImport = eval("(url) => import(url)");
importModule = /** @type {(url: URL) => Promise<EXPECTED_ANY>} */ (
dynamicImport
);
}
importModule(pathToFileURL(loader.path)).then(
(/** @type {EXPECTED_ANY} */ module) => {
handleResult(loader, module, callback);
},
callback
);
} catch (err) {
callback(/** @type {Error} */ (err));
}
return;
}
let loadedModule;
try {
loadedModule = require(loader.path);
} catch (err) {
// node can choke on require when the FD limit is hit; defer to recover.
if (
err instanceof Error &&
/** @type {NodeJS.ErrnoException} */ (err).code === "EMFILE"
) {
setImmediate(loadLoader, loader, callback);
return;
}
return callback(/** @type {Error} */ (err));
}
return handleResult(loader, loadedModule, callback);
}
module.exports = loadLoader;