Fix: no-restricted-syntax - correct the schema

[bradzacher]

What is the purpose of this pull request? (put an "X" next to item)

[x] Bug fix (template)

What did you do? Please include the actual source code causing the issue.
configured the rule invalidly:

{
  rules: {
    'no-restricted-syntax': ['error', 'FunctionExpression', 1, false, [], {}],
  }
}

What did you expect to happen?
eslint fails with a configuration validation errors

What actually happened? Please include the actual, raw output from ESLint.
the rule ran fine with no errors.

---

For reference, running the current schema through jsonschemavalidator.net:

Running the new schema through jsonschemavalidator.net:

Running a lint with the new schema:

Error: .eslintrc.js:
        Configuration for rule "no-restricted-syntax" is invalid:
        Value 1 should be string.
        Value 1 should be object.
        Value 1 should match exactly one schema in oneOf.

[platinumazure]

Thanks for contributing!

Is this testable? Answer might be no. But it's always good to see if we could avoid regressions here.

[bradzacher]

Unfortunately it's not. If you run the rule tester with a config that goes against the schema, it'll just throw an error and fail the test.

Could potentially add tests outside of the standard rule testing tooling - up to you if you think that's a good idea.

---

I only found the issue because I've been doing some work to automatically generate typescript types based off of the rule's json schema.

I've found rules in other plugins which had similar invalid schemas.

[kaicataldo]

LGTM, thanks for contributing!

[platinumazure]

Thanks @bradzacher for the explanation, as well as digging in and finding these issues. I don't think it's critical to add tests at this time, but other team members may think otherwise.

[g-plane]

LGTM, thanks!

[aladdin-add]

LGTM, thanks!