From b0c9a3810fcc7e749cb70c27947320f58114a352 Mon Sep 17 00:00:00 2001
From: Louise Foussat <louisefoussat@gmail.com>
Date: Tue, 2 Mar 2021 19:17:52 +0000
Subject: [PATCH] add tell-it-cypher subject and tests

---
 js/tests/tell-it-cypher_test.mjs  | 135 ++++++++++++++++++++++++++++++
 subjects/tell-it-cypher/README.md |  18 ++++
 2 files changed, 153 insertions(+)
 create mode 100644 js/tests/tell-it-cypher_test.mjs
 create mode 100644 subjects/tell-it-cypher/README.md

diff --git a/js/tests/tell-it-cypher_test.mjs b/js/tests/tell-it-cypher_test.mjs
new file mode 100644
index 000000000..31157911a
--- /dev/null
+++ b/js/tests/tell-it-cypher_test.mjs
@@ -0,0 +1,135 @@
+import * as cp from 'child_process'
+import fs from 'fs/promises'
+import { join, resolve, isAbsolute } from 'path'
+import { tmpdir } from 'os'
+import { promisify } from 'util'
+const mkdir = fs.mkdir
+const rmdir = fs.rmdir
+const writeFile = fs.writeFile
+const readFile = fs.readFile
+
+const exec = promisify(cp.exec)
+
+export const tests = []
+const name = 'tell-it-cypher'
+// maybe get the sames from an api? like https://parser.name/
+const guests = [
+  'Shyam Langley',
+  'Austin Harwood',
+  'Reem Morgan',
+  'Neal Chamberlain',
+  'Ryan Walters',
+  'Ocean Battle',
+  'Ubaid Ballard',
+  'Victoria Chan',
+  'Dominika Mullen',
+  'Heath Denton',
+  'Lilith Hamilton',
+  'Aisling Bailey',
+  'Maizie Love',
+  'Nathanial Franco',
+  'Charmaine Bernard',
+  'Sohail Downes',
+  'Rabia Gomez',
+  'Brendan Brennan',
+  'Shannen Atherton',
+  'Esa Villarreal',
+  'Kayla Wynn',
+  'Gladys Hardy',
+  'Laaibah Rogers',
+  'Zishan Randolph',
+  'Connor Connolly',
+  'Arabella Wooten',
+  'Edna Floyd',
+]
+const shuffle = (arr) => {
+  let i = arr.length
+  let j, tmp
+  while (--i > 0) {
+    j = Math.floor(Math.random() * (i + 1))
+    tmp = arr[j]
+    arr[j] = arr[i]
+    arr[i] = tmp
+  }
+  return arr
+}
+const getRandomList = (names) =>
+  shuffle(names).slice(0, Math.floor(Math.random() * (names.length - 10) + 10))
+const getExpected = (list) =>
+  list
+    .map((n) =>
+      n
+        .split(' ')
+        .reverse()
+        .join(' '),
+    )
+    .sort()
+    .map((g, i) => `${i + 1}. ${g}`)
+    .join('\n')
+
+export const setup = async () => {
+  const dir = tmpdir()
+
+  // check if already exists and rm?
+  await mkdir(`${dir}/${name}`)
+  const randomList = getRandomList(guests)
+  const decoded = getExpected(randomList)
+  const encoded = Buffer.from(decoded).toString('base64')
+  await writeFile(`${dir}/${name}/encoded.txt`, encoded)
+  await writeFile(`${dir}/${name}/decoded.txt`, decoded)
+
+  return { tmpPath: `${dir}/${name}`, decoded, encoded }
+}
+const cypherIt = async ({ keyword, newFile, ctx, path, eq }) => {
+  const scriptPath = join(resolve(), path)
+  const filename = keyword === "encode" ? "decoded.txt" : "encoded.txt"
+  await exec(`node ${scriptPath} ${filename} ${keyword} ${newFile ? newFile : ""}`, {
+    cwd: ctx.tmpPath,
+  })
+  const newFileName = newFile || (keyword === "encode" ? "cypher.txt" : "clear.txt")
+  const out = await readFile(`${ctx.tmpPath}/${newFileName}`, 'utf8').catch((err) =>
+    err.code === 'ENOENT' ? 'output file not found' : err,
+  )
+  await exec(`rm ${newFileName}`, { cwd: ctx.tmpPath })
+  return eq(out, keyword === "encode" ? ctx.encoded : ctx.decoded)
+}
+
+tests.push(async ({ path, eq, ctx }) => {
+  return cypherIt({
+    path,
+    eq,
+    ctx,
+    keyword: 'encode',
+  })
+})
+
+tests.push(async ({ path, eq, ctx }) => {
+  return cypherIt({
+    path,
+    eq,
+    ctx,
+    keyword: 'decode',
+  })
+})
+
+tests.push(async ({ path, eq, ctx }) => {
+  return cypherIt({
+    path,
+    eq,
+    ctx,
+    keyword: 'encode',
+    newFile: 'mysecret.txt',
+  })
+})
+
+tests.push(async ({ path, eq, ctx }) => {
+  return cypherIt({
+    path,
+    eq,
+    ctx,
+    keyword: 'decode',
+    newFile: 'pandora.txt',
+  })
+})
+
+Object.freeze(tests)
diff --git a/subjects/tell-it-cypher/README.md b/subjects/tell-it-cypher/README.md
new file mode 100644
index 000000000..646b649dc
--- /dev/null
+++ b/subjects/tell-it-cypher/README.md
@@ -0,0 +1,18 @@
+## tell-it-cypher
+
+### Instructions
+
+FINALLY, you got the names.
+But you could forget it... loose it... How could you write it without puting the surprise in danger?!
+
+Create a `tell-it-cypher.mjs` script that:
+- Takes a file as first argument
+- Takes one of these keywords as second argument:
+  - `encode`: convert your file from `utf8` to `base64`, then save the result in a `cypher.txt` file.
+  - `decode`: convert your file from `base64` to `utf8`, then save the result in a `clear.txt` file.
+- Could take a string as third argument and use it as the new file name. Extension must be precised.
+
+### Notions
+
+- [Node buffer: `.from()`](https://nodejs.org/docs/latest/api/buffer.html#buffer_static_method_buffer_from_string_encoding)
+- [Node buffer: `.toString()`](https://nodejs.org/api/buffer.html#buffer_buf_tostring_encoding_start_end)