vue3-core/packages/compiler-sfc/src/script/defineModel.ts

import type { LVal, Node, TSType } from '@babel/types'
import type { ScriptCompileContext } from './context'
import { inferRuntimeType } from './resolveType'
import {
  UNKNOWN_TYPE,
  concatStrings,
  isCallOf,
  toRuntimeTypeString,
} from './utils'
import { BindingTypes, unwrapTSNode } from '@vue/compiler-dom'

export const DEFINE_MODEL = 'defineModel'

export interface ModelDecl {
  type: TSType | undefined
  options: string | undefined
  identifier: string | undefined
  runtimeOptionNodes: Node[]
}

export function processDefineModel(
  ctx: ScriptCompileContext,
  node: Node,
  declId?: LVal,
): boolean {
  if (!isCallOf(node, DEFINE_MODEL)) {
    return false
  }

  ctx.hasDefineModelCall = true

  const type =
    (node.typeParameters && node.typeParameters.params[0]) || undefined
  let modelName: string
  let options: Node | undefined
  const arg0 = node.arguments[0] && unwrapTSNode(node.arguments[0])
  const hasName = arg0 && arg0.type === 'StringLiteral'
  if (hasName) {
    modelName = arg0.value
    options = node.arguments[1]
  } else {
    modelName = 'modelValue'
    options = arg0
  }

  if (ctx.modelDecls[modelName]) {
    ctx.error(`duplicate model name ${JSON.stringify(modelName)}`, node)
  }

  let optionsString = options && ctx.getString(options)
  let optionsRemoved = !options
  const runtimeOptionNodes: Node[] = []

  if (
    options &&
    options.type === 'ObjectExpression' &&
    !options.properties.some(p => p.type === 'SpreadElement' || p.computed)
  ) {
    let removed = 0
    for (let i = options.properties.length - 1; i >= 0; i--) {
      const p = options.properties[i]
      const next = options.properties[i + 1]
      const start = p.start!
      const end = next ? next.start! : options.end! - 1
      if (
        (p.type === 'ObjectProperty' || p.type === 'ObjectMethod') &&
        ((p.key.type === 'Identifier' &&
          (p.key.name === 'get' || p.key.name === 'set')) ||
          (p.key.type === 'StringLiteral' &&
            (p.key.value === 'get' || p.key.value === 'set')))
      ) {
        // remove runtime-only options from prop options to avoid duplicates
        optionsString =
          optionsString.slice(0, start - options.start!) +
          optionsString.slice(end - options.start!)
      } else {
        // remove prop options from runtime options
        removed++
        ctx.s.remove(ctx.startOffset! + start, ctx.startOffset! + end)
        // record prop options for invalid scope var reference check
        runtimeOptionNodes.push(p)
      }
    }
    if (removed === options.properties.length) {
      optionsRemoved = true
      ctx.s.remove(
        ctx.startOffset! + (hasName ? arg0.end! : options.start!),
        ctx.startOffset! + options.end!,
      )
    }
  }

  ctx.modelDecls[modelName] = {
    type,
    options: optionsString,
    runtimeOptionNodes,
    identifier:
      declId && declId.type === 'Identifier' ? declId.name : undefined,
  }
  // register binding type
  ctx.bindingMetadata[modelName] = BindingTypes.PROPS

  // defineModel -> useModel
  ctx.s.overwrite(
    ctx.startOffset! + node.callee.start!,
    ctx.startOffset! + node.callee.end!,
    ctx.helper('useModel'),
  )
  // inject arguments
  ctx.s.appendLeft(
    ctx.startOffset! +
      (node.arguments.length ? node.arguments[0].start! : node.end! - 1),
    `__props, ` +
      (hasName
        ? ``
        : `${JSON.stringify(modelName)}${optionsRemoved ? `` : `, `}`),
  )

  return true
}

export function genModelProps(ctx: ScriptCompileContext) {
  if (!ctx.hasDefineModelCall) return

  const isProd = !!ctx.options.isProd
  let modelPropsDecl = ''
  for (const [name, { type, options }] of Object.entries(ctx.modelDecls)) {
    let skipCheck = false

    let runtimeTypes = type && inferRuntimeType(ctx, type)
    if (runtimeTypes) {
      const hasBoolean = runtimeTypes.includes('Boolean')
      const hasUnknownType = runtimeTypes.includes(UNKNOWN_TYPE)

      if (isProd || hasUnknownType) {
        runtimeTypes = runtimeTypes.filter(
          t =>
            t === 'Boolean' ||
            (hasBoolean && t === 'String') ||
            (t === 'Function' && options),
        )

        skipCheck = !isProd && hasUnknownType && runtimeTypes.length > 0
      }
    }

    let runtimeType =
      (runtimeTypes &&
        runtimeTypes.length > 0 &&
        toRuntimeTypeString(runtimeTypes)) ||
      undefined

    const codegenOptions = concatStrings([
      runtimeType && `type: ${runtimeType}`,
      skipCheck && 'skipCheck: true',
    ])

    let decl: string
    if (runtimeType && options) {
      decl = ctx.isTS
        ? `{ ${codegenOptions}, ...${options} }`
        : `Object.assign({ ${codegenOptions} }, ${options})`
    } else {
      decl = options || (runtimeType ? `{ ${codegenOptions} }` : '{}')
    }
    modelPropsDecl += `\n    ${JSON.stringify(name)}: ${decl},`

    // also generate modifiers prop
    const modifierPropName = JSON.stringify(
      name === 'modelValue' ? `modelModifiers` : `${name}Modifiers`,
    )
    modelPropsDecl += `\n    ${modifierPropName}: {},`
  }
  return `{${modelPropsDecl}\n  }`
}