build: add files of vant-cli 2

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

@@ -0,0 +1,46 @@
+import postcss from 'postcss';
+import postcssrc from 'postcss-load-config';
+import { parse } from 'path';
+import { render as renderLess } from 'less';
+import { renderSync as renderSass } from 'sass';
+import { readFileSync, writeFileSync } from 'fs';
+import { replaceExt } from '../common';
+import { POSTCSS_CONFIG_FILE } from '../common/constant';
+
+async function compilePostcss(filePath: string, source: string | Buffer) {
+  const config = await postcssrc({}, POSTCSS_CONFIG_FILE);
+  const output = await postcss(config.plugins as any).process(source, {
+    from: undefined
+  });
+
+  writeFileSync(filePath, output);
+}
+
+async function compileLess(filePath: string) {
+  const source = readFileSync(filePath, 'utf-8');
+  const { css } = await renderLess(source, {
+    filename: filePath
+  });
+
+  return css;
+}
+
+async function compileSass(filePath: string) {
+  const { css } = renderSass({ file: filePath });
+  return css;
+}
+
+export async function compileStyle(filePath: string) {
+  const parsedPath = parse(filePath);
+
+  if (parsedPath.ext === '.less') {
+    const source = await compileLess(filePath);
+    await compilePostcss(replaceExt(filePath, '.css'), source);
+  } else if (parsedPath.ext === '.scss') {
+    const source = await compileSass(filePath);
+    await compilePostcss(replaceExt(filePath, '.css'), source);
+  } else {
+    const source = readFileSync(filePath, 'utf-8');
+    await compilePostcss(filePath, source);
+  }
+}