解决 import type declarations can only be used in TypeScript filesType assertion (断言) expressions can only

配置vetur

"typescript.validate.enable": false,
  "javascript.validate.enable": false,
  "vetur.validation.script": false,
  "vetur.validation.template": false,
  "diffEditor.ignoreTrimWhitespace": false,
  "css.validate": false,
  "less.validate": false,
  "scss.validate": false,
  "vetur.validation.style": false

或者卸载 vetur 使用 volar