react/scripts/rollup/plugins/use-forks-plugin.js

89 lines
2.7 KiB
JavaScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
'use strict';
const path = require('path');
const semver = require('semver');
function resolveRelatively(importee, importer) {
if (semver.gte(process.version, '8.9.0')) {
return require.resolve(importee, {
paths: [path.dirname(importer)],
});
} else {
// `paths` argument is not available in older Node.
// This works though.
// https://github.com/nodejs/node/issues/5963
const Module = require('module');
return Module._findPath(importee, [
path.dirname(importer),
...module.paths,
]);
}
}
let resolveCache = new Map();
function useForks(forks) {
let resolvedForks = new Map();
Object.keys(forks).forEach(srcModule => {
// Fork paths are relative to the project root. They must include the full
// path, including the extension. We intentionally don't use Node's module
// resolution algorithm because 1) require.resolve doesn't work with ESM
// modules, and 2) the behavior is easier to predict.
const targetModule = forks[srcModule];
resolvedForks.set(
path.resolve(process.cwd(), srcModule),
// targetModule could be a string (a file path),
// or an error (which we'd throw if it gets used).
// Don't try to "resolve" errors, but cache
// resolved file paths.
typeof targetModule === 'string'
? path.resolve(process.cwd(), targetModule)
: targetModule
);
});
return {
name: 'scripts/rollup/plugins/use-forks-plugin',
resolveId(importee, importer) {
if (!importer || !importee) {
return null;
}
if (importee.startsWith('\u0000')) {
// Internal Rollup reference, ignore.
// Passing that to Node file functions can fatal.
return null;
}
let resolvedImportee = null;
let cacheKey = `${importer}:::${importee}`;
if (resolveCache.has(cacheKey)) {
// Avoid hitting file system if possible.
resolvedImportee = resolveCache.get(cacheKey);
} else {
try {
resolvedImportee = resolveRelatively(importee, importer);
} catch (err) {
// Not our fault, let Rollup fail later.
}
if (resolvedImportee) {
resolveCache.set(cacheKey, resolvedImportee);
}
}
if (resolvedImportee && resolvedForks.has(resolvedImportee)) {
// We found a fork!
const fork = resolvedForks.get(resolvedImportee);
if (fork instanceof Error) {
throw fork;
}
return fork;
}
return null;
},
};
}
module.exports = useForks;