unknown support for 'array-type'

[ThomasdenH]

Bug Report

• TSLint version: 5.11.0
• TypeScript version: 3.0.1
• Running TSLint via: CLI

TypeScript code being linted

const a: unknown[] = [];

with tslint.json configuration:

{
  "rules": {
    "array-type": [true, "array-simple"],
  }
}

Actual behavior

TSLint recommends Array<unknown> instead of unknown[].

Expected behavior

unknown[] is considered a simple type and thus be preferred over Array<unknown>.

[johnwiseheart]

We should definitely accept the unknown type as a simple type. Happy to review a PR for this.

[ThomasdenH]

Since unknown was added in Typescript 3.0.0, how to add this rule with backwards compatibility?