index.js•1.38 kB
const path = require('path');
const extension = require('./lib/extension');
const normalize = require('./lib/normalize');
const register = require('./lib/register');
exports.prepare = function (extensions, filepath, cwd, nothrow) {
var option, attempt;
var attempts = [];
var err;
var onlyErrors = false;
var ext = extension(filepath);
if (Object.keys(require.extensions).indexOf(ext) !== -1) {
return true;
}
var config = normalize(extensions[ext]);
if (!config) {
if (nothrow) {
return;
} else {
throw new Error('No module loader found for "'+ext+'".');
}
}
if (!cwd) {
cwd = path.dirname(path.resolve(filepath));
}
if (!Array.isArray(config)) {
config = [config];
}
for (var i in config) {
option = config[i];
attempt = register(cwd, option.module, option.register);
error = (attempt instanceof Error) ? attempt : null;
if (error) {
attempt = null;
}
attempts.push({
moduleName: option.module,
module: attempt,
error: error
});
if (!error) {
onlyErrors = false;
break;
} else {
onlyErrors = true;
}
}
if (onlyErrors) {
err = new Error('Unable to use specified module loaders for "'+ext+'".');
err.failures = attempts;
if (nothrow) {
return err;
} else {
throw err;
}
}
return attempts;
};