What this snippet does
A class decorator must return either void or a constructor function; returning a primitive causes a runtime TypeError.
Expected output
TypeError: Class decorator 'Bad' returned a value that is not a constructor.
Why practise typing this
Typing decorators code builds muscle memory for the symbols and indentation TypeScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More TypeScript practice
- Applying a basic class decoratorDecorators · advanced
- Injecting metadata into a classDecorators · advanced
- Logging method calls with a decoratorDecorators · advanced
- Depracating a method safelyDecorators · advanced
- Losing 'this' context in method decoratorsDecorators · advanced
- Basic property decoratorDecorators · advanced