Version: 0.0.1. Currently collecting feedback.

This is a proposal for vuejs/vue#7186. It tries to standardize a "Vue Type" format that Vetur could read from and enhance the HTML editing experience in Vue SFC. This proposal is not about type-checking in Vue SFC.

Feedback welcome! You can join the discussion or open new issues here. Specifically, I would want to know:

• What more features would you want from the editor, based on the Vue Types data?
• Where do you think is the right place to author those data (Vue SFC as JSDocs, Vue SFC Custom Block, another file that you can import from Vue SFC, a centralized file for the whole library)?

TypeScript has a great ecosystem for typings, for example, run npm i -D @types/node and get auto completion & type check working in the editor. We want the same for using Vue libraries. For example, if I do npm i -D @vuetypes/element-ui, I should get all HTML tag and attribute auto completion & attribute value checking in the editor.

For that to happen, we need 3 things:

• A way to write those "vue types" in Vue components (SFC and JS/TS), and a tool to extract those typings into a specified format.
• A repo to store high-quality "vue types" and a NPM scope to download it from. Similar to DefinitelyTyped/DefinitelyTyped and @types, we could have vuejs/VerilyTyped and @vuetypes.
• Editor integration (Vetur / VLS) that reads the specified format and provides the desired features, including:
  • Auto completion
  • Error checking
  • Hover information
  • Jump to website doc

The rest of the document describes the "specified format".

Components should provide:

• A short description of the component.
• Its allowed attributes.
• Its required attributes.
• (?) Whether the component can only be a child of another component. For example, el-checkbox-group and el-checkbox.

Attributes should provide:

• A short description of the attribute.
• Its allowed values. If the values are enums, it should also provide short descriptions for those enum values.

{
  "components": [
    {
      "name": "v-button",
      "description": "A button",
      "attributes": [
        {
          "name": "width",
          "description": "The width of the button",
          "type": "number",
          "required": true
        },
        {
          "name": "height",
          "description": "The height of the button",
          "type": "number",
          "required": true
        },
        {
          "name": "corner-style",
          "description": "The style of the button's corner",
          "type": "string",
          "enum": [
            { "value": "round", "description": "Round corners" },
            { "value": "sharp", "description": "Sharp corners" }
          ],
          "required": false,
          "default": "round"
        }
      ]
    }
  ]
}

• <v| should auto complete <v-button|>.
• <v-button w|> should auto complete <v-button width="">.
• <v-button corner-style="|"> should auto complete round and sharp.

• <v-btn> should show error, as v-btn is not a defined component.
• <v-button width="">, <v-button width="20px">, <v-button width="foo"> should show error, as the provided values do not satisfy the valueType requirement.
• <v-button width="50"></-button> should show error, as required attribute height is not provided.
• <v-button /> should show error, as required attributes width and height are not provided.
• <v-button corner-style="square"> should show error, as square is not one of the enum values for corner-style.

• "A button" should show when hovering on <v-button>.
• "The style of the button's corner" should show when hover on corner-style in <v-button corner-style="round">.

If the website has a URL for each component / attribute, we could provide a command that allows user to jump to the website for a more comprehensive doc. This can be part of the hover / completion information, or just a special command.

I'm not sure if we want this. Although we could provide a link field in the spec for each component / attribute and easily achieve this in the editor.

After building a JSON following the spec, you have two options to distribute it:

• Put it in the NPM module you are publishing, and add a key vueTypes that points to the path of the file. Benefit is the JSON always has the right version.
• Publish it a VerilyTyped, which can automatically publish it to vuetypes. (I don't know if this is worth the hassle)