vant/packages/vant-cli/src/compiler/compile-style.ts

import { parse } from 'path';
import { readFileSync, writeFileSync } from 'fs';
import { replaceExt } from '../common';
import { compileCss } from './compile-css';
import { compileLess } from './compile-less';
import { compileSass } from './compile-sass';
import { logger } from '../common/logger';

async function compileFile(filePath: string) {
  const parsedPath = parse(filePath);

  try {
    if (parsedPath.ext === '.less') {
      const source = await compileLess(filePath);
      return await compileCss(source);
    }

    if (parsedPath.ext === '.scss') {
      const source = await compileSass(filePath);
      return await compileCss(source);
    }

    const source = readFileSync(filePath, 'utf-8');
    return await compileCss(source);
  } catch (err) {
    logger.error('Compile style failed: ' + filePath);
    throw err;
  }
}

export async function compileStyle(filePath: string) {
  const css = await compileFile(filePath);

  writeFileSync(replaceExt(filePath, '.css'), css);
}