remark-clang-format/code/format-code.js

run clang-format for code in markdown

import { spawnSync as spawnSync } from 'child_process';
import * as prettier from 'prettier';
import { visit } from 'unist-util-visit';
import { prettierPluginLatex } from '@unified-latex/unified-latex-prettier';

function visitor(node) {
  if (
    node.type == 'code' &&
    node.lang &&
    (!node.meta || !node.meta.includes('nolint')) &&
    node.value &&
    !node.value.includes('--8<--')
  ) {
    switch (node.lang) {
      case 'c++':
      case 'cpp':
      case 'c': {
        const child = spawnSync('clang-format', { input: node.value });
        if (child.stderr && child.stderr.length > 0) {
          console.warn(
            '[remark-clang-format] stderr: ',
            child.stderr.toString(),
          );
          break;
        }
        if (!child.stdout) {
          console.warn('[remark-clang-format] empty stdout');
          console.warn('[remark-clang-format] original code: ', node.value);
          console.warn('[remark-clang-format] child info', child);
          // node value left untouched
        } else {
          node.value = child.stdout;
        }
        break;
      }

      case 'python':
      case 'py': {
        const child = spawnSync('ruff', ['format', '-'], {
          input: node.value,
        });
        if (child.stderr && child.stderr.length > 0) {
          console.warn('[remark-ruff] stderr: ', child.stderr.toString());
          break;
        }
        if (!child.stdout) {
          console.warn('[remark-ruff] empty stdout');
          console.warn('[remark-ruff] original code: ', node.value);
          console.warn('[remark-ruff] child info', child);
          // node value left untouched
        } else {
          node.value = child.stdout.toString().trimEnd();
        }
        break;
      }

      case 'javascript':
      case 'typescript':
      case 'js':
      case 'ts': {
        const formatted = prettier
          .format(node.value, {
            parser: 'babel',
            endOfLine: 'auto',
            semi: true,
            singleQuote: true,
            trailingComma: 'all',
          })
          .trimEnd(); // Prettier inserts trailing line which we do not want
        node.value = formatted;
        break;
      }

      case 'tex': {
        const formatted = prettier
          .format(node.value, {
            plugins: [prettierPluginLatex],
            parser: 'latex-parser',
          })
          .trimEnd();
        node.value = formatted;
        break;
      }
    }
  }
}

export default function formatCode(tree) {
  visit(tree, ['code'], visitor);
}