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A toy CommonJS implementation
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| import fs from "node:fs"; | |
| import path from "node:path"; | |
| import url from "node:url"; | |
| const cache = {}; | |
| function createRequire(filename) { | |
| function require(specifier) { | |
| const resolved = require.resolve(specifier); | |
| if (resolved in cache) { | |
| return cache[resolved].exports; | |
| } | |
| const contents = fs.readFileSync(resolved, "utf8"); | |
| const module = { | |
| loaded: false, | |
| exports: {}, | |
| }; | |
| const fn = new Function( | |
| "module", | |
| "exports", | |
| "require", | |
| "__dirname", | |
| "__filename", | |
| contents, | |
| ); | |
| let innerRequire; | |
| cache[resolved] = module; | |
| fn( | |
| module, | |
| module.exports, | |
| function require(specifier) { | |
| if (!innerRequire) { | |
| innerRequire = createRequire(resolved); | |
| } | |
| return innerRequire(specifier); | |
| }, | |
| path.dirname(resolved), | |
| resolved, | |
| ); | |
| module.loaded = true; | |
| return module.exports; | |
| } | |
| require.resolve = (specifier) => { | |
| let resolved = path.resolve(path.dirname(filename), specifier); | |
| if (fs.existsSync(resolved)) { | |
| return resolved; | |
| } | |
| if (fs.existsSync(resolved + ".js")) { | |
| return resolved + ".js"; | |
| } | |
| }; | |
| require.cache = cache; | |
| return require; | |
| } | |
| const require = createRequire(url.fileURLToPath(import.meta.url)); | |
| require(process.argv[2]); |
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