Alias table does not recognise another alias as key

[pouwelsjochem]

Environment

name	version
IDEA version	IC2020.3
Luanalysis version	1.2.2
OS	MacOS Big Sur

What are the steps to reproduce this issue?

---@alias aOrB "a"|"b"
---@alias aAndBPropertyAlias {a:true, b:true}
---@alias aAndBStringAlias {["a"]:true, ["b"]:true}
---@shape aAndBShape
---@field a true
---@field b true

local b = "b" ---@type aOrB

local abPropertyAlias = --[[---@type aAndBPropertyAlias]] {}
abPropertyAlias["a"] = true
abPropertyAlias.b = true
abPropertyAlias[b] = true -- No such indexer '["a"]' found on type '{ a: true, b: true } || No such indexer '["b"]' found on type '{ a: true, b: true }'

local abStringAlias = --[[---@type aAndBStringAlias]] {}
abStringAlias["a"] = true -- No such member 'a' found on type '{ ["a"]: true, ["b"]: true }' 
abStringAlias.b = true -- No such member 'b' found on type '{ ["a"]: true, ["b"]: true }' 
abStringAlias[b] = true

local abShape = --[[---@type aAndBShape]] {}
abShape["a"] = true
abShape.b = true
abShape[b] = true

What happens?

When using the '{}' format with either the @param or @alias annotation it doesn't recognise the keys correctly.
Using {a:true, b:true} breaks when using another alias as key.
Using {["a"]:true, ["b"]:true} does the opposite, it breaks when not using an alias

What were you expecting to happen?

The '{}' format to work the same as a @shape does. As far as I can tell these effectively define the same type of table structure.

[Benjamin-Dobell]

The issue wasn't really related to aliases, but rather that "doc tables" were initially much more limited than shapes. The main issue was no generics, but I later added generic aliases so you can emulate generic doc tables.

I've now gone back and made doc tables behave more like @shape. The main difference is doc tables cannot inherit from other doc tables. They also can't represent a callable type. Aside from that, they should now be pretty comparable.

In a follow-up commit to the one referenced above, I added support for inheriting from doc table aliases, or any @alias that references a legal type.