webpack config appears to be re-executed once for every resolve attempt

[mogelbrod]

This greatly increases execution times for non-trivial webpack.config.js files. It would be great if the config would only be required and instantiated once, using memoization if necessary.

node-filing-cabinet/index.js

Lines 302 to 352 in 754d388

	function resolveWebpackPath({dependency, filename, directory, webpackConfig}) {
	if (!webpackResolve) {
	webpackResolve = require('enhanced-resolve');
	}
	webpackConfig = path.resolve(webpackConfig);
	let loadedConfig;
	try {
	loadedConfig = require(webpackConfig);
	if (typeof loadedConfig === 'function') {
	loadedConfig = loadedConfig();
	}
	} catch (e) {
	debug('error loading the webpack config at ' + webpackConfig);
	debug(e.message);
	debug(e.stack);
	return '';
	}
	const resolveConfig = Object.assign({}, loadedConfig.resolve);
	if (!resolveConfig.modules && (resolveConfig.root || resolveConfig.modulesDirectories)) {
	resolveConfig.modules = [];
	if (resolveConfig.root) {
	resolveConfig.modules = resolveConfig.modules.concat(resolveConfig.root);
	}
	if (resolveConfig.modulesDirectories) {
	resolveConfig.modules = resolveConfig.modules.concat(resolveConfig.modulesDirectories);
	}
	}
	try {
	const resolver = webpackResolve.create.sync(resolveConfig);
	// We don't care about what the loader resolves the dependency to
	// we only wnat the path of the resolved file
	dependency = stripLoader(dependency);
	const lookupPath = isRelative(dependency) ? path.dirname(filename) : directory;
	return resolver(lookupPath, dependency);
	} catch (e) {
	debug('error when resolving ' + dependency);
	debug(e.message);
	debug(e.stack);
	return '';
	}
	}

[mrjoelkemp]

Hey @mogelbrod. Thanks for raising this. You're right!

Looks like TS has that type of preloaded config support. Webpack would follow a similar path.

Happy to review a PR with tests if you're open to it. Otherwise we can wait and see if anyone else has this issue and is willing to contribute a PR.

[mogelbrod]

Hi again! Sorry for the late response.
I haven't used the library since May and so haven't really had a reason to fix this myself - so it's up for grabs if anybody else wants to try 👍