TypeScript interface that allows other properties

by

If you want ActionPayload to accept any other property you can add an indexer:

interface ActionPayload {
    actionType: string;

    // Keys can be strings, numbers, or symbols.
    // If you know it to be strings only, you can also restrict it to that.
    // For the value you can use any or unknown, 
    // with unknown being the more defensive approach.
    [x: string | number | symbol]: unknown;
}

See https://github.com/Microsoft/TypeScript/wiki/Breaking-Changes#strict-object-literal-assignment-checking

More Related Contents:

  1. How to define Typescript type as a dictionary of strings but with one numeric “id” property
  2. Expression ___ has changed after it was checked
  3. Could not find a declaration file for module ‘module-name’. ‘/path/to/module-name.js’ implicitly has an ‘any’ type
  4. How to suppress “error TS2533: Object is possibly ‘null’ or ‘undefined'”?
  5. Why does A | B allow a combination of both, and how can I prevent it?
  6. TypeScript conditional types – filter out readonly properties / pick only required properties
  7. Typescript: infer type of generic after optional first generic
  8. Typescript Discriminated Union allows invalid state
  9. Why can’t I return a generic ‘T’ to satisfy a Partial?
  10. Define global constants
  11. What does ‘declare’ do in ‘export declare class Actions’?
  12. “parserOptions.project” has been set for @typescript-eslint/parser
  13. How to use namespaces with import in TypeScript
  14. angular2 bootstrap with data from ajax call(s)
  15. Interface is allowing extra property when it is used as return type of a function
  16. Typescript: What’s the difference between an optional field and a union with undefined?
  17. Typescript: what is a “naked type parameter”
  18. Naming of TypeScript union and intersection types
  19. Specify return type in TypeScript arrow function
  20. Global types in typescript
  21. Typescript Error: type ‘string’ can’t be used to index type X
  22. Typescript and spread operator?
  23. Angular 2 ngModel in child component updates parent component property
  24. Getting the return type of a function which uses generics
  25. Angular 2 loader on each http request
  26. Typescript: type narrowing not working for `in` when key is stored in a variable
  27. Run factory function on import in TypeScript?
  28. How do I decide whether @types/* goes into `dependencies` or `devDependencies`?
  29. Self-referencing return type for static methods in inheriting classes
  30. How to place a dynamic component in a container

Leave a Comment