feat: Test running overhaul, switch to Prettier & reformat everything (#1407)

* chore: Switch to Node 20 + Vitest

* chore: migrate to vitest mock functions

* chore: code style (switch to prettier)

* test: re-enable long-running test

Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime!

see #1193

* chore: code style

* chore: fix failing tests

* Updated Documentation in README.md

* Update contribution guidelines to state usage of Prettier

* fix: set prettier printWidth back to 80

* chore: apply updated code style automatically

* fix: set prettier line endings to lf again

* chore: apply updated code style automatically

---------

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>

.github/workflows/UpdateDirectory.js

@@ -0,0 +1,71 @@
+import path from 'path'
+import fs from 'fs'
+import { globby } from 'globby'
+
+function pathPrefix (i) {
+  const res = '  '.repeat(i)
+  return res + '*'
+}
+
+function printPath (oldPath, newPath, output) {
+  const oldParts = oldPath.split(path.sep)
+  const newParts = newPath.split(path.sep)
+
+  for (let i = 0; i < newParts.length; ++i) {
+    const newPart = newParts[i]
+    if (i + 1 > oldParts.length || oldParts[i] !== newPart) {
+      if (newPart) {
+        output.push(`${pathPrefix(i)} **${newPart.replace('_', ' ')}**`)
+      }
+    }
+  }
+
+  return newPath
+}
+
+function pathsToMarkdown (filePaths) {
+  const output = []
+
+  let oldPath = ''
+  filePaths.sort(function (a, b) {
+    if (a.toLowerCase() < b.toLowerCase()) return -1
+    if (a.toLowerCase() > b.toLowerCase()) return 1
+    return 0
+  })
+
+  for (let filepath of filePaths) {
+    let filename = path.basename(filepath)
+    filepath = path.dirname(filepath)
+
+    if (filepath !== oldPath) {
+      oldPath = printPath(oldPath, filepath, output)
+    }
+
+    let indent = filepath.split(path.sep).length
+
+    // prepare the markdown-esque prefix to the file's line
+    const prefix = pathPrefix(indent)
+
+    // remove extension from filename
+    const name = path.basename(filename, ".js")
+    const url = path.join(filepath, filename)
+
+    output.push(`${prefix} [${name}](${url})`)
+  }
+
+  return output.join('\n')
+}
+
+// get paths of all .js files - excluding node_modules, the .github folder, tests and config stuff
+globby([
+  '**/*.js',
+  '!(node_modules|.github)/**/*',
+  "!**/test/**/*",
+  '!**/*.test.js',
+  '!**/*.manual-test.js',
+  '!vitest.config.ts'
+])
+  // create markdown content
+  .then(pathsToMarkdown)
+  // write markdown to file
+  .then(markdown => fs.writeFileSync('DIRECTORY.md', markdown + '\n', { encoding: 'utf8' }))