What?

Adds support for inferred pipeline types like this:

How?

• A generic type representation of the commands array is stored on the Pipeline class itself
• The type of .chain is then updated to return a Pipeline type with whatever command was just chained fed into the class-level generic
• Finally, the type of .exec is updated to return the type of the commands array mapped to each item's response type. Kept the empty case as unknown[] for backward compatibility.

Gotchas

TS thinks that each .chain call returns a new Pipeline instance, which means that the type inference only works if the chain is kept intact from pipeline() to exec(). Splitting the pipeline up for use in loops etc will still require manually overriding exec<['like', 'this']>

const p = redis.pipeline()

for (const x of [1,2,3]) {
  p.set('foo', 'bar')
  p.get('baz')
}

const result = await p.exec() // TS: const result: unknown[]