How to Have Multiple Object Field Types in Record Type Inferred by Function Arguments

When working with TypeScript, you may come across a situation where you need to define a record type with multiple object field types inferred by function arguments. In this blog post, we will explore different solutions to achieve this.

Solution 1: Union Types

One way to have multiple object field types in a record type is by using union types. Union types allow you to specify multiple possible types for a field.

    type MyRecord = {
      field1: string | number;
      field2: boolean | string[];
    };
  

In the above example, the field1 can be either a string or a number, while field2 can be either a boolean or an array of strings.

Solution 2: Intersection Types

Another approach is to use intersection types. Intersection types allow you to combine multiple types into one.

    type Field1Type = {
      field1: string;
    };
    
    type Field2Type = {
      field2: boolean;
    };
    
    type MyRecord = Field1Type & Field2Type;
  

In the above example, we define two separate types for field1 and field2, and then combine them using the intersection operator (&) to create the MyRecord type.

Solution 3: Generics

Generics provide a flexible way to define types that can be parameterized. We can use generics to define a record type with multiple object field types inferred by function arguments.

    type MyRecord = {
      field1: T;
      field2: U;
    };
  

In the above example, T and U are generic type parameters that can be replaced with any types when using MyRecord.

Conclusion

In this blog post, we explored different solutions to have multiple object field types in a record type inferred by function arguments in TypeScript. We discussed using union types, intersection types, and generics. Depending on your specific use case, you can choose the solution that best fits your needs.