Using betterer with alternative typescript version

[iyegoroff]

Hi @phenomnomnominal !

I want to upgrade typescript version in a project that uses outdated version. Is it possible to specify an alternative version of typescript inside betterer test?

[phenomnomnominal]

Sorry for never getting back to you on this!

I'm sure this is no longer useful, but just for the record I think the solution here would be to make a local copy of the typescript test and import the newer version of TypeScript there. Otherwise maybe some shenanigans with a workspace to have a folder with a different version of TS installed maybe? I can't think of a good way to do it with the main @betterer/typescript package without locking it to a TS version which feels like a mistake overall?

Let me know if you came up with a solution!

[phenomnomnominal]

Just incase anyone comes across this in the future, here's a couple options as a solution:

1) Make a copy of the @betterer/typescript test in your project.

Pros: easy, hopefully understandable
Cons: may diverge from the latest version

First install the version of TypeScript that you need for the test with an alias:

npm install typescript-betterer@npm:typescript@5

Then change the import in the local copy of the test:

import ts from 'typescript-betterer';

2) Patch the installed @betterer/typescript test using patch-package:

Pros: will diverge less from the latest version (but still might require reworking the patch.
Cons: kind of evil

First install the version of TypeScript that you need with an alias:

npm install typescript-betterer@npm:typescript@5

Then change the import in the installed test in node_modules/@betterer/typescript:

import ts from 'typescript-betterer';

Then run:

npx patch-package @betterer/typescript

Then add patch-package to your module scripts:

 "scripts": {
   "postinstall": "patch-package"
 }

Hope this helps!