Script to update ol/ul indents from 2 to 4 spaces (#20384)

* Script to update ol/ul indents from 2 to 4 spaces

* Update commonmark-indent.js

* Update commonmark-indent.js

script/content-migrations/commonmark-indent.js

@@ -0,0 +1,87 @@
+#!/usr/bin/env node
+
+/*
+
+As we update our markdown rendering pipeline,
+the package update includes a new markdown rendering engine,
+micromark, that is CommonMark compliant. The most obvious change is that
+indents within `ul` and `ol` now require 4 spaces or a tab instead of
+2 spaces. This script updates our content to that specification.
+*/
+
+import walkSync from 'walk-sync'
+import fs from 'fs/promises'
+
+/******************************************************************************/
+
+async function readFiles(opts) {
+  const paths = walkSync('./', {
+    directories: false,
+    includeBasePath: true,
+    ...opts,
+  })
+  return await Promise.all(paths.map(async (path) => [path, await fs.readFile(path, 'utf8')]))
+}
+
+function withAllFiles(files, fn) {
+  return files.map(([path, file]) => [path, fn(path, file)])
+}
+
+async function writeFiles(files) {
+  return await Promise.all(files.map(async ([path, file]) => await fs.writeFile(path, file)))
+}
+
+/******************************************************************************/
+
+function updateIndent(path, file) {
+  // We don't want to change the frontmatter
+  let [, frontmatter, content] = file.split(/^-{3,}$/gm)
+
+  // If the file doesn't have frontmatter or content, meh
+  if (!frontmatter || !content) return file
+
+  // If there no `ul` or `ol`, no change
+  if (!/^([-*]\s)|(\d+[.)]\s)/gi.test(content)) return file
+
+  // If this file has a yaml example, skip it; its too hard to update automatically
+  if (/^\s*`{3}ya?ml/gim.test(content)) {
+    if (/^ {2,3}(\S)/gm.test(content)) {
+      console.log('YAML example, will skip', path)
+    }
+    return file
+  }
+
+  // Only within a `ul` or `ol`, update indent level
+  content = content
+    .split('\n')
+    .map((line, index, arr) => {
+      // If this isn't an indented line, continue
+      if (!/^ {2,3}(\S)/.test(line)) return line
+
+      // Find the previous line that is not whitespace or indented
+      let prevLineIndex = index - 1
+      while (/^\s*$/.test(arr[prevLineIndex]) || /^\s{2,}/.test(arr[prevLineIndex])) {
+        prevLineIndex--
+      }
+
+      // Only do it if previous line is ol/ul
+      const prevLine = arr[prevLineIndex]
+      if (!/^([-*]\s)|(\d+[.)]\s)/i.test(prevLine)) return line
+
+      return line.replace(/^ {2,3}(\S)/, '    $1')
+    })
+    .join('\n')
+
+  return ['---', frontmatter.trim(), '---', '', content.trim(), ''].join('\n')
+}
+
+async function main() {
+  let files = await readFiles({
+    globs: ['content/**/*.md', 'data/**/*.md'],
+    ignore: ['**/README.md'],
+  })
+  files = withAllFiles(files, updateIndent)
+  await writeFiles(files)
+}
+
+main()