--print-config doesn't print extended rulesets

[JoshuaKGoldberg]

Bug Report

• TSLint version: 5.18.0
• TypeScript version: N/A
• Running TSLint via: CLI

Suppose your TSLint configuration extends from tslint-config-prettier:

{
    "extends": ["tslint-config-prettier"]
}

...and you run tslint --print-config ./tslint.json on it...

Actual behavior

...you get a json blurb that starts with:

{
  "extends": [],
...
}

Expected behavior

For typescript-eslint/tslint-to-eslint-config#2, it'd be useful to print the configurations extended from.

[JoshuaKGoldberg]

Note: although TSLint is no longer accepting most feature requests (#4534), this one would make migrating to typescript-eslint easier. It will remain open.

[ChaiWithJai]

@JoshuaKGoldberg finally got approval to start working on OSS Fellowship. Would love to pair with you on this, if possible.

[JoshuaKGoldberg]

Awesome, great to hear that @JBhagat841! 🙌

#4744, which added the --print-config flag, is a good place to start if you're curious about where the code that launches the flag comes from. findConfiguration and extendConfigurationFile are good starting places within the existing code separate from that PR to see how the configurations are extended.

Feel free to ping me on gitter.im -either in https://gitter.im/palantir/tslint or as a DM- if you want a more real-time Q&A format. Since we're both in NYC (we've met IRL, right? 😆) I think we could coordinate something in person through that too!

[JoshuaKGoldberg]

💀 It's time! 💀

TSLint is deprecated and no longer accepting pull requests other than security fixes. See #4534. ☠️
We recommend you instead use typescript-eslint to lint your TypeScript code with ESLint. ✅

👋 It was a pleasure open sourcing with you!

[JoshuaKGoldberg]

🤖 Beep boop! 👉 TSLint is deprecated 👈 and you should switch to typescript-eslint! 🤖

🔒 This issue is being locked to prevent further unnecessary discussions. Thank you! 👋