Add interface-over-type-literal rule

[ghost]

PR checklist

• Addresses an existing issue: New rules for linting type declarations #1844
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

What changes did you make?

Added the interface-over-type-literal rule. This forbids type T = { ... }, preferring interface T { ... }.

[ghost]

This was left in by accident.

[nchen63]

@andy-ms thanks!

[itajaja]

Hi, just out of curiosity, can you point me to some rationale behind this?

[ghost]

It's stylistic. Generally interface T { foo(): void; } and type T = { foo(): void; } mean the same thing (although an interface can be extended). I think the latter style was mostly coming from people familiar with flow, where there is a difference.

[itajaja]

thanks for the explanation :)