fix: await postcss for async plugins (#1036)

Author: ocavue

src/esbuild/postcss.ts

@@ -103,7 +103,7 @@ export const postcssPlugin = ({
           }
 
           // Transform CSS
-          const result = postcss
+          const result = await postcss
             ?.default(plugins)
             .process(contents, { ...options, from: args.path })
 

test/__snapshots__/index.test.ts.snap

@@ -552,3 +552,8 @@ exports[`support baseUrl and paths in tsconfig.json in --dts-resolve build 1`] =
 export { foo };
 "
 `;
+
+exports[`support tailwindcss postcss plugin 1`] = `
+"\\"use strict\\";
+"
+`;

test/index.test.ts

@@ -337,6 +337,29 @@ test('import css', async () => {
   expect(outFiles).toEqual(['input.css', 'input.js'])
 })
 
+test('support tailwindcss postcss plugin', async () => {
+  const { output, outFiles } = await run(getTestName(), {
+    'input.ts': `
+      import './foo.css'
+    `,
+    'postcss.config.js': `
+      module.exports = {
+        plugins: {
+          tailwindcss: {},
+          autoprefixer: {},
+        }
+      }
+    `,
+    'foo.css': `
+      @tailwind base;
+      @tailwind components;
+      @tailwind utilities;
+    `,
+  })
+  expect(output).toMatchSnapshot()
+  expect(outFiles).toEqual(['input.css', 'input.js'])
+})
+
 test('import css in --dts', async () => {
   const { output, outFiles } = await run(
     getTestName(),

test/package.json

@@ -4,11 +4,13 @@
     "@egoist/path-parser": "1.0.4",
     "@types/react": "17.0.50",
     "@types/react-dom": "17.0.17",
+    "autoprefixer": "10.4.16",
     "graphql": "^15.3.0",
     "graphql-tools": "^5.0.0",
     "react": "17.0.2",
     "react-dom": "17.0.2",
     "react-select": "5.7.0",
+    "tailwindcss": "3.3.5",
     "vue": "3.2.36",
     "vue-router": "4.0.15"
   },