_REAMDE.md

Convert markdown indented code blocks to fenced code blocks

This script runs on a folder and converts all the indented code blocks in markdown files to fenced code blocks.

The script tries to preserve the original markdown formatting.

Usage

npm install
node index.js ../../my-project/content/

Use bundle

I bundled the script into a zero-dep single js-exectuable

You can download it and run:

node convert.js ../../my-project/content

index.js

// run `node index.js` in the terminal
import { remark } from 'remark';
import { readFileSync, writeFileSync } from 'fs';
import remarkFrontmatter from 'remark-frontmatter';
import { visit } from 'unist-util-visit';
import * as glob from 'glob';
import stripIndent from 'strip-indent';
import indentString from 'indent-string';

function convertIndentedToFenced(filePath) {
  const doc = readFileSync(filePath, 'utf-8');

  const outputDoc = doc.split('');
  console.log;
  let changeOffset = 0;

  let hasCode = false;
  const file = remark()
    .use(remarkFrontmatter)
    .use(function detector() {
      return (tree) => {
        visit(tree, 'code', (node) => {
          if (node.lang) return;
          hasCode = true;
          // fix identation by removing extra indent
          const value = stripIndent(node.value);
          const from = node.position.start.offset;
          const to = node.position.end.offset;
          const indentLevel = Math.round(node.position.start.column / 4) * 4;

          const newBlock =
            ' '.repeat(
              Math.max(0, indentLevel - node.position.start.column + 1)
            ) +
            '```\n' +
            indentString(value + '\n```', indentLevel);

          outputDoc.splice(
            from + changeOffset,
            to - from,
            ...newBlock.split('')
          );
          changeOffset = changeOffset + newBlock.length - (to - from);
        });
      };
    })
    .processSync(doc);

  if (hasCode) {
    console.log(`Updating ${filePath} in-place`);
    writeFileSync(filePath, outputDoc.join(''), 'utf-8');
  } else {
    console.log(`Skip ${filePath} as it doesn't contain code blocks`);
  }
}

const dir = process.argv[2];
if (!dir) {
  console.log('Error: provide directory as argument');
  process.exit(10);
}

const mdFiles = glob.sync(dir + '/**/*.md', { nodir: true });

for (const f of mdFiles) {
  convertIndentedToFenced(f);
}

package.json

{
  "name": "convert-indented-to-fenced-md",
  "type": "module",
  "version": "0.0.0",
  "dependencies": {
    "glob": "^10.3.10",
    "indent-string": "^5.0.0",
    "remark": "^15.0.1",
    "remark-frontmatter": "^5.0.0",
    "strip-indent": "^4.0.0"
  }
}