Fix MadeEnum<'a'> to be compatible with MadeEnum<string>
#3227
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Disallow direct access to member values when referencing generically
```ts
let Color: MadeEnum<'red' | 'blue'>;
let AnEnum: MadeEnum<string>;
```
Without this change `Color` can't be assigned to `AnEnum`, because
the TS defines the member values as an index: `{ [x: string]: string }`.
So since one has an index accessor and one doesn't,
making them incompatible.
The `entry()` arg type change also allows them to be compatible.
Without it TS thinks something like `entry()` fn accepting any `string`
is not compatible with `entry()` fn only accepting `'red' | 'blue'`.
Using another generic at the function level somehow works around this,
while still maintaining all the strictness.
brentkulwicki
approved these changes
Jun 4, 2024
PR incoming for Workflow, which will have a state enum, typed generically. |
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Two changes to make this compatible.
First, disallow direct access to member values when referencing generically.
Without this change
Colorcan't be assigned toAnEnum, because the TS defines the member values as an index:{ [x: string]: string }. So since one has an index accessor and one doesn't, making them incompatible.Secondly, The
entry()arg type change also allows them to be compatible. Without it TS thinks something likeentry()fn accepting anystringis not compatible withentry()fn only accepting'red' | 'blue'. Using another generic at the function level somehow works around this, while still maintaining all the strictness.