Ordner und stat

// entries: [{name, size, isDirectory}], as readdir and stat describe them.
// Folders first, then files, each sorted by name; a summary line last.
export function summarize(entries) {
  return entries.map((e) => e.name);
}

const entries = [
  {name: 'notes.txt', size: 120, isDirectory: false},
  {name: 'img', size: 4096, isDirectory: true},
  {name: 'README.md', size: 30, isDirectory: false}
];
console.log(summarize(entries).join('\n'));

import {test} from 'node:test';
import assert from 'node:assert/strict';
import {summarize} from './main.js';

const entries = [
  {name: 'notes.txt', size: 120, isDirectory: false},
  {name: 'img', size: 4096, isDirectory: true},
  {name: 'README.md', size: 30, isDirectory: false}
];

test('zuerst Ordner, dann Dateien, jeweils nach Namen sortiert', () => {
  const got = summarize(entries).slice(0, 3);
  assert.deepEqual(got, ['img/', 'README.md (30 bytes)', 'notes.txt (120 bytes)'], `die ersten Zeilen waren ${JSON.stringify(got)}`);
});

test('die letzte Zeile zählt die Ordner, die Dateien und deren Bytes', () => {
  const got = summarize(entries).at(-1);
  assert.equal(got, '1 folders, 2 files, 150 bytes', `die letzte Zeile war ${JSON.stringify(got)}`);
});

test('auch zwei Ordner werden sortiert', () => {
  const got = summarize([{name: 'src', size: 4096, isDirectory: true}, {name: 'docs', size: 4096, isDirectory: true}]);
  assert.deepEqual(got, ['docs/', 'src/', '2 folders, 0 files, 0 bytes'], `summarize lieferte ${JSON.stringify(got)}`);
});

test('ein leerer Ordner ergibt nur die Zusammenfassungszeile', () => {
  const got = summarize([]);
  assert.deepEqual(got, ['0 folders, 0 files, 0 bytes'], `summarize([]) lieferte ${JSON.stringify(got)}`);
});

{
  "type": "module"
}

import {mkdir, readdir, rm, stat, writeFile} from 'node:fs/promises';
import {join} from 'node:path';

// Describes the entries of dir as {name, size, isDirectory}, sorted by name.
// A missing dir gives an empty list; every other error is thrown again.
export async function describe(dir) {
  let names;
  try {
    names = await readdir(dir);
  } catch {
    return [];
  }
  return names.map((name) => ({name, size: 0, isDirectory: false}));
}

// A sample folder next to main.js, made afresh on every run.
const sample = join(import.meta.dirname, 'sample');
await rm(sample, {recursive: true, force: true});
await mkdir(join(sample, 'img'), {recursive: true});
await writeFile(join(sample, 'todo.txt'), 'buy milk\n');
await writeFile(join(sample, 'README.md'), '# Sample\n');
for (const r of await describe(sample)) console.log(r.isDirectory ? r.name + '/' : r.name + ' ' + r.size + ' bytes');
console.log('missing:', await describe(join(import.meta.dirname, 'missing')));

import {test} from 'node:test';
import assert from 'node:assert/strict';
import {runMain} from './learnrun.js';
import {describe} from './main.js';

test('gibt den Beispielordner nach Namen sortiert aus, mit den Dateigrößen', async () => {
  const got = (await runMain()).trimEnd().split('\n').slice(0, 3);
  assert.deepEqual(got, ['README.md 9 bytes', 'img/', 'todo.txt 9 bytes'], `das Programm gab ${JSON.stringify(got)} aus`);
});

test('ein fehlender Ordner ergibt eine leere Liste', async () => {
  const last = (await runMain()).trimEnd().split('\n').at(-1);
  assert.equal(last, 'missing: []', `die letzte Zeile war ${JSON.stringify(last)}`);
});

test('eine Datei statt eines Ordners lehnt mit ENOTDIR ab', async () => {
  await assert.rejects(describe(new URL('./main.js', import.meta.url)), {code: 'ENOTDIR'}, 'describe auf main.js sollte mit dem Code ENOTDIR ablehnen');
});

{
  "type": "module"
}