Simple prop declaration replaces "" with nothing when auto-fixing

[carestad]

Tell us about your environment

• ESLint version: v6.7.1
• eslint-plugin-vue version: v6.0.1
• Node version: v12.13.0

Please show your full configuration:

{
    "extends": [
        "eslint:recommended",
        "plugin:vue/recommended"
    ],
    "plugins": [
        "vue"
    ]
}

What did you do?

<template>
  <div>
    <h1>Hello</h1>
  </div>
</template>

<script>
export default {
  name: 'Test',
  props: {
    foo: "",
  },
};
</script>

Running eslint test.vue gives me the following:

And then after running eslint --fix test.vue

What did you expect to happen?

Not sure what I expected, but did not expect it to just replace "" with nothing, leaving the JS invalid.

What actually happened?

{
  props: {
    foo: "",
  }
}

was turned into

{
  props: {
    foo: ,
  }
}

[LinusBorg]

I'd say this rule isn't really be --fix-able , as we can at best take an educated guess that you meant it to be a string and should be foo: String instead of foo: "".

[carestad]

I'd say this rule isn't really be --fix-able , as we can at best take an educated guess that you meant it to be a string and should be foo: String instead of foo: "".

Would that be possible? Or maybe rather assume that foo: "" could be rewritten to foo: null (allow any type) at least. Or just skip these declarations altogether.

[LinusBorg]

Since the developer intent can't be properly inferred, silently assuming null when he developer may expect the prop validation to fail when something besides a string is passed would be dangerous.

The developer appearantly wanted to define the prop (likely to be a String), but failed to do so in the correct way/syntax, so it should simply fail and not be corrected, leaving that to the developer.

[carestad]

Since the developer intent can't be properly inferred, silently assuming null when he developer may expect the prop validation to fail when something besides a string is passed would be dangerous.

The developer appearantly wanted to define the prop (likely to be a String), but failed to do so in the correct way/syntax, so it should simply fail and not be corrected, leaving that to the developer.

Yeah, I agree on that.

But why is "" even removed in the first place and not just left as-is? It would at least still work afterwords.

[ota-meshi]

Thank you for this issue.

I think it is a bug that the code is deleted.