fix(compiler-sfc): fix rewrite named export default (#1675)

packages/compiler-sfc/__tests__/rewriteDefault.spec.ts

@@ -0,0 +1,29 @@
+import { rewriteDefault } from '../src'
+
+describe('compiler sfc: rewriteDefault', () => {
+  test('without export default', () => {
+    expect(rewriteDefault(`export  a = {}`, 'script')).toMatchInlineSnapshot(`
+      "export  a = {}
+      const script = {}"
+    `)
+  })
+
+  test('rewrite export default', () => {
+    expect(
+      rewriteDefault(`export  default {}`, 'script')
+    ).toMatchInlineSnapshot(`"const script = {}"`)
+  })
+
+  test('rewrite export named default', () => {
+    expect(
+      rewriteDefault(
+        `const a = 1 \n export { a as b, a as default, a as c}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const a = 1 
+       export { a as b,  a as c}
+      const script = a"
+    `)
+  })
+})