Proposal: Follow program flow in constructor when strictPropertyInitialization = true

Search Terms

constructor strictPropertyInitialization flow

Suggestion

TypeScript should follow unconditional function calls in constructor when checking for strict property initialization.

Use Cases

It is a common pattern to be able to reset objects after construction and, thus, to transfer object initialization to a separate routine:

class C
{
  private p: number;

  public constructor() { Initialize() }

  public Initialize() { p = 0; }
}

Currently, TypeScript doesn't consider functions being unconditionally called from within a constructor function when checking for strict property initialization. The above code yields a compiler error.

I propose TypeScript to be able to analyse code flow and recognize property initialization that's performed in functions unconditionally called by the constructor function.

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.

Commencez par suivre les vérifications de strictPropertyInitialization du compilateur pour les constructeurs et les appels de fonction inconditionnels ; l'issue ne mentionne aucun fichier ni test. Déterminez comment le flux de contrôle passant par une méthode Initialize définie séparément devrait affecter l'initialisation des propriétés, puis ajoutez une couverture montrant que l'exemple est accepté tandis que les appels non inconditionnels restent rejetés.