vue-component-meta: No way to identify array v.s. tuple

[thomasaull]

Vue - Official extension or vue-tsc version

—

VSCode version

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Vue version

3.5.16

TypeScript version

5.8.3

System Info

package.json dependencies

Steps to reproduce

Run vue-component-meta with the following component:

<template>
  <slot />
</template>

<script setup lang="ts">
type TupleAlias = [string]

export interface Props {
  tuple: [string]
  stringArray: string[]
  tupleAlias: TupleAlias
}

const props = withDefaults(defineProps<Props>(), {})
</script>

What is expected?

The exported type information should allow to identify a tuple

What is actually happening?

The output is as follows (stripped unnecessary parts):

{
  "type": 1,
  "props": [
    {
      "name": "tuple",
      "global": false,
      "description": "",
      "tags": [],
      "required": true,
      "type": "[string]",
      "declarations": [
        {
          "file": "[...]/FixedArray.vue",
          "range": [115, 136]
        }
      ],
      "schema": { "kind": "array", "type": "[string]", "schema": ["string"] }
    },
    {
      "name": "stringArray",
      "global": false,
      "description": "",
      "tags": [],
      "required": true,
      "type": "string[]",
      "declarations": [
        {
          "file": "[...]/FixedArray.vue",
          "range": [139, 154]
        }
      ],
      "schema": { "kind": "array", "type": "string[]", "schema": ["string"] }
    },
    {
      "name": "tupleAlias",
      "global": false,
      "description": "",
      "tags": [],
      "required": true,
      "type": "TupleAlias",
      "declarations": [
        {
          "file": "[...]/FixedArray.vue",
          "range": [157, 179]
        }
      ],
      "schema": { "kind": "array", "type": "TupleAlias", "schema": ["string"] }
    }
  ]
}

As you can see the schema for all three props is ["string"] regardless if it’s a string[] or [string] type. In my project I have the requirement to make a clear distinction between tuples and regular arrays, which is currently not possible as it seems. I could check if the type starts with [ but this breaks with the tupleAlias example

Link to minimal reproduction

No response

Any additional comments?

No response

[thomasaull]

I found a workaround:

• Enable the rawType option when creating the checker with the createChecker method:

  const checker =  createChecker('path/to/tsconfig.json', { rawType: true })

• Get the type checker:

  const program = checker.__internal__.tsLs.getProgram()
  const typeChecker = program.getTypeChecker()

• Use the rawType and the typeChecker to check for a tuple

  const isTuple = typeChecker.isTupleType(prop.rawType)