Auto fix compilerOptions Lib

[RubenSandwich]

Search Terms

compilerOptions Lib, autofix Lib, auto Lib generation, Auto compilerOptions

Suggestion

Suggest adding the appropriate library to compilerOptions.lib if you are using a feature that requires it.

Use Cases

• Help the developer code by preventing them from having to look up which compilerOptions.lib setting they need to use a particual feature of the standard library. As it is difficult to remember which version of ES introduced which additions.
• In the future this could be used to auto generate the compilerOptions.Lib the developer needs by the JS features they are using. Which would remove some configuration. 🎉

Examples

Object.entities(object).map(([key, value]) => {
  ...
});

📎💬 “Looks like your using Object.entities, would you like to add 'es2017.object' to your compilerOptions.lib?”

---

if (array.includes(testValue)) {
  ...
}

📎💬 “Looks like your using Array.include, would you like to add 'es2016.array.include' to your compilerOptions.lib?”

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

[orta]

A simpler PR for this would probably look a lot like #32281

It could be built in one of two ways:

• There could be a known symbol map of most common mistakes like this, and what they would need to add to lib
• A more comprehensive answer, but more complex, could be to look at the diagnostic for missing symbol and then search through all shipped lib.x.d.ts files to see if it's included and raise with the associated lib recommendation

[RyanCavanaugh]

This is nice but we should also make it clear to the user that this API is nominally not available in the version they say they are targeting, not just that TS wants them to say the magic words.