Internal consistent-docs-url rule crashes if meta isn't present

[s4san]

Tell us about your environment

• ESLint Version: master
• Node Version: n/a
• npm Version: n/a

What parser (default, Babel-ESLint, etc.) are you using?

Default

Please show your full configuration:

According to the internal ESLint config around rules:

rules:
    rulesdir/consistent-docs-url: "error"

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

module.exports = {
};

module.exports = {
  meta: undefined
};

npm run lint

What did you expect to happen?

Either a lint error about the lack of meta or nothing if that is covered by another rule.

What actually happened? Please include the actual, raw output from ESLint.

For configuration 1:
ESLint crashes, with an error message from context.report that the node location must be passed if the node is not passed.

For configuration 2:
ESLint throws an exception that it is trying to access property length of undefined

This happened when I was trying to fix #10722

As mentioned in this comment,

Case 1: meta property is not defined on the exports object.

This crashes eslint and curiously, the exportsNode is of type functionExpression.

Case 2: meta property is defined with a value of undefined

This creates an exception in getPropertyFromObject method where it tries to access length of undefined.

[s4san]

Case 1 is already covered by no-invalid-meta so there's nothing to do there.

Case 2 is only relevant when someone explicitly defines meta to either one of Array, Function, String or Number (undefined and null are already handled by no-invalid-meta)

I will create a PR for case 2.