Use Flow / Typescript with project generated by vue-cli@3

It can be confusing to see FlowJS + Typescript. The idea is not to create the perfect startup, but try to add Typescript in an existing project with Babel (with or without FlowJS).

• Typescript / TSX: App.ts
• babel: typescript/flow/jsx added in presets
• eslint: display errors with flowtype/flowtype-errors
• composition-api used to create component with hook style
• vue-property-decorator used to create component with class style
• jsx has been used to be able to check types in "html"
• scoped style in jsx

TC39 Specifying

• https://github.com/tc39/proposal-optional-chaining
• https://github.com/tc39/proposal-decorators

Related projects:

• https://github.com/shenron/babel-node-starter
• https://github.com/shenron/flow-node-boilerplate