import { join as joinPath, dirname, extname } from 'path' import { fileURLToPath } from 'url' import { deepStrictEqual } from 'assert' import * as fs from 'fs' const { readFile, writeFile } = fs.promises global.window = global global.fetch = url => { // this is a fake implementation of fetch for the tester // -> refer to https://devdocs.io/javascript/global_objects/fetch const accessBody = async () => { throw Error('body unavailable') } return { ok: false, type: 'basic', status: 500, statusText: 'Internal Server Error', json: accessBody, text: accessBody, } } const wait = delay => new Promise(s => setTimeout(s, delay)) const fail = fn => { try { fn() } catch (err) { return true } } const props = [String,Array] .flatMap(({ prototype }) => Object.getOwnPropertyNames(prototype) .map(key => ({ key, value: prototype[key], src: prototype }))) .filter(p => typeof p.value === 'function') const eq = (a, b) => { const changed = [] for (const p of props) { !p.src[p.key] && (changed[changed.length] = p) } for (const p of changed) { p.src[p.key] = p.value } deepStrictEqual(a, b) for (const p of changed) { p.src[p.key] = undefined } return true } const [solutionPath, name] = process.argv.slice(2) const fatal = (...args) => { console.error(...args) process.exit(1) } solutionPath || fatal('missing solution-path, usage:\nnode test solution-path exercise-name') name || fatal('missing exercise, usage:\nnode test solution-path exercise-name') const ifNoEnt = fn => err => { if (err.code !== 'ENOENT') throw err fn(err) } const root = dirname(fileURLToPath(import.meta.url)) const read = (filename, description) => readFile(filename, 'utf8').catch( ifNoEnt(() => fatal(`Missing ${description} for ${name}`)), ) const modes = { '.js': 'function', '.mjs': 'node', '.json': 'inline' } const readTest = filename => readFile(filename, 'utf8') .then(test => ({ test, mode: modes[extname(filename)] })) const stackFmt = (err, url) => { for (const p of props) { p.src[p.key] = p.value } if (err instanceof Error) return err.stack.split(url).join(`${name}.js`) throw Error(`Unexpected type thrown: ${typeof err}. usage: throw Error('my message')`) } const any = arr => new Promise(async (s, f) => { let firstError const setError = err => firstError || (firstError = err) await Promise.all(arr.map(p => p.then(s, setError))) f(firstError) }) const testNode = async ({ name }) => { const path = `${solutionPath}/${name}.mjs` return { path, url: joinPath(root, `${name}_test.mjs`), code: await read(path, 'student solution'), } } const runInlineTests = async ({ json, name }) => { const restore = new Set() const equal = deepStrictEqual const saveArguments = (src, key) => { const savedArgs = [] const fn = src[key] src[key] = (...args) => { savedArgs.push(args) return fn(...args) } restore.add(() => (src[key] = fn)) return savedArgs } const logs = [] console.log = (...args) => logs.push(args) const die = (...args) => { logs.forEach((args) => console.info(...args)) console.error(...args) process.exit(1) } const solution = await loadAndSanitizeSolution(name) for (const { description, code } of JSON.parse(json)) { logs.length = 0 const [provided, tests] = code.includes('// Your code') ? code.split('// Your code') : ['', code] const fullCode = ` ${provided ? '// Provided setup' : ''} ${provided.trim()} // Your code ${solution.code.trim()} // The tests ${tests.trim()}`.trim() try { eval(fullCode) console.info(`${description}:`, 'PASS') } catch (err) { console.info(`${description}:`, 'FAIL') console.info(`\n======= Code ======= \n${fullCode}`) console.info('\n======= Error ======') die(' ->', err.message) } } } const loadAndSanitizeSolution = async name => { const path = `${solutionPath}/${name}.js` const rawCode = await read(path, "student solution") // this is a very crude and basic removal of comments // since checking code is only use to prevent cheating // it's not that important if it doesn't work 100% of the time. const code = rawCode.replace(/\/\*[\s\S]*?\*\/|\/\/.*/g, "").trim() if (code.includes("import")) fatal("import keyword not allowed") return { code, rawCode, path } } const runTests = async ({ url, path, code }) => { const { setup, tests } = await import(url).catch(err => fatal(`Unable to execute ${name} solution, error:\n${stackFmt(err, url)}`), ) const randStr = (n = 7) => Math.random().toString(36).slice(2, n) const between = (min, max) => { max || (max = min, min = 0) return Math.floor(Math.random() * (max - min) + min) } const upperFirst = (str) => str[0].toUpperCase() + str.slice(1) const tools = { eq, fail, wait, code, path, randStr, between, upperFirst } tools.ctx = (await (setup && setup(tools))) || {} for (const [i, t] of tests.entries()) { try { if (!(await t(tools))) { throw Error('Test failed') } } catch (err) { console.log(`test #${i+1} failed:\n${t.toString()}\n\nError:`) fatal(stackFmt(err, url)) } } console.log(`${name} passed (${tests.length} tests)`) } const main = async () => { const { test, mode } = await any([ readTest(joinPath(root, `${name}.json`)), readTest(joinPath(root, `${name}_test.js`)), readTest(joinPath(root, `${name}_test.mjs`)), ]).catch(ifNoEnt((err) => fatal(`Missing test for ${name}`))) if (mode === "node") return runTests(await testNode({ test, name })) if (mode === "inline") return runInlineTests({ json: test, name }) const { rawCode, code, path } = await loadAndSanitizeSolution(name) const parts = test.split("// /*/ // ⚡") const [inject, testCode] = parts.length < 2 ? ["", test] : parts const combined = `${inject.trim()}\n${rawCode .replace(inject.trim(), "") .trim()}\n${testCode.trim()}\n` const b64 = Buffer.from(combined).toString("base64") const url = `data:text/javascript;base64,${b64}` return runTests({ path, code, url }) } main().catch(err => fatal(err.stack))