Encapsulate type refactoring

Search Terms

• refactoring
• encapsulate
• return, function

Suggestion

Add a refactoring that encapsulates a given instance of a type and updates uses of it. Encapsulating would wrap the type in an object type that has a single property of that type.

Use cases

My original use case would be to convert a single returned type to an object that can return multiple values:

1. Start

   function foo(): number { return Date.now(); }
   const z = foo(); 
   

2. Select number and run encapsulate
3. Result

   function foo(): { value: number } { return { value: Date.now() }; }
   const z = foo().value; 
   

This could also be used for individual parameters in a function:

1. Start

   function foo(x: number) { return x * 2; }
   foo(1);
   

2. Select number and run encapsulate
3. Result

   function foo(x: { value: number }) { return x.value * 2; }
   foo({ value: 1 });
   

This may fall under some larger class of refactoring, I'm just not sure what to call it

The issue names no files or tests; use the foo return-type and parameter examples as the acceptance cases. First inspect the repository’s existing refactoring entry points and tests. Done means an Encapsulate action transforms both a selected return type and a function parameter, updating the shown call sites to use the resulting { value: ... } shape.