Incorrect ts(2783) error when class attribute appear in template syntax more than once after update vue-tsc to latest version

[mmis1000]

Versions

"typescript": "^4.9.3",
"vue-tsc": "^1.0.10"

<template>
  <div class="a" v-bind="{ class: {b: true} }" />
</template>

This cause an error that don't actually exist

error TS2783: 'class' is specified more than once, so this usage will be overwritten.

Because vue sfc explicitly allow multi class and style to exist at same time, vue-tsc should not report error on such usage.

The template above outputs as

function render(_ctx, _cache) {
  return (_openBlock(), _createElementBlock("div", _mergeProps({ class: "a" }, { class: {b: true} }), null, 16 /* FULL_PROPS */))
}

Which works totally fine and nothing is overwritten.

[sawmurai]

Getting the same error with this:

<slot name="label" v-bind="{name}">
<!-- ... -->
</slot>

Error:

'name' is specified more than once, so this usage will be overwritten.ts(2783)

[cawa-93]

From docs:

In addition, the :class directive can also co-exist with the plain class attribute. So given the following state:

Unlike other attributes, class and style are not overwritten, but combined from all attributes. See demo: https://stackblitz.com/edit/vitejs-vite-vvfozp?file=src/App.vue

[sawmurai]

Hello! I'm afraid the error case with a duplicate name still exists:

<slot name="label" v-bind="{name}">
<!-- ... -->
</slot>

[cawa-93]

@sawmurai I think for name is correct error sinse vue will owerride it. Only class, style and onXX props may be merged.
See https://github.com/vuejs/core/blob/c6e5bda27d13554675d68dbe33b07f3474467aa6/packages/runtime-core/src/vnode.ts#L816-L845

[sawmurai]

I think this is kind of a special case because the first name is the name of the slot, and the second name is a bound symbol. So, nothing is supposed to be merged here.

Edit: This would be an example https://sfc.vuejs.org/#eNo9UDtuwzAMvQqjxS1QW+gaKAG69QZdtDi2HDvQDyKdDoLuXsoKqknvg8dHZvEV4/DcjTgLhVPaIgEa2uNV+83FkAgyJLNAgSUFBx1bO+21n4JHAj86A5dqeOu+jbUBfkKy8+nUvWuvZAvkKAZkXLQjGUYAav285gwO71CKkowOdvNxJ3j2LszGXrRgXYsmoQ1tHNO0mr5iLdh72/zMXK5aebk1qboAHI/nHDVLaYySTeN6nMFfJf+7iQ/Rtu7dGIcHBs93yUfkS0AtznAwleNrVKzFShTxLCUuU73mA4eQ7pJ/Q9o9bc4MBl1/S+EXTeJgLWoENyqi/AF27oJj

Edit2: Or this with a separate component https://sfc.vuejs.org/#eNplUstqwzAQ/JWNenALtU2vwQmUXvoBhV50SeJN7KAX0jqlGP17V5ITEoovu5pldmbWs3h3rrlMKNaiCwc/OoKANLmtNKN21hN8WO3g6K2GqmlTk8arGzyDxyPEZaJA0hysCQRmpxE2aeC5+kSlLHxbr/rVqnqRpmvLPt7EDaF2akfIHUA3vG3nGXQ4QYxdy11+HY2bCC61tj2qjRSMS1GgpCtXkm5U8EQD1kFZ4tk5aYnLOMDXgMAaCQ2tgVdlpTEWsGsf1WTXXN69i1dR/Nd655pzsIYDnLOABQhSMHMhlIJzSb0UA5EL67YNx0PK8Rwa608tV42fDI0aGwy63nv7E9AzsRSJgoVFXnlNPx3rTiJ77sfL4qxLhrMfdn0NQAqObT+a/n8SV8tpbLFbyB5S4Pb+7wD6dZmf9TH6cG0plOUvCb+dWMQ/4ZjQ7Q==

[sawmurai]

Thinking about it, maybe the special case here is v-bind or slot-bindings in general :)

[sawmurai]

@johnsoncodehk Do you want me to open a new issue maybe?