[Compiler API] Reuse default compiler host when customizing module resolution

Suggestion

A very similar question already has been asked here four years ago by @vivin:
Implementing custom module-resolution logic using Compiler API - StackOverflow

I need the same right now, and it is a pity that apparently, you still need to rewrite the entire compiler host configuration just in order to customize one aspect. What I would prefer to do would be something like:

const host = ts.createCompilerHost(options);
host.resolveModuleNames = myResolver;
const program = ts.createProgram(sourceFiles, options, host);

But this still seems to be impossible right now?

🔍 Search Terms

customize module resolution, configure compiler host, resolveModuleNames

✅ Viability 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, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

💻 Use Cases

• customize compiler more easily without reinventing the wheel
• if you need to reinvent the wheel, the code will get harder to maintain against future changes to the default compiler host

Inizia tracciando i punti di ingresso della Compiler API indicati nell’issue: ts.createCompilerHost, resolveModuleNames e ts.createProgram. Determina in che modo l’host del compilatore predefinito gestisce la risoluzione dei moduli e come si potrebbe sovrapporre a esso un resolver personalizzato; il lavoro è completato quando la personalizzazione richiesta funziona senza ricreare l’intera configurazione dell’host.