Third decorator gets called twice

[fireflysemantics]

Here's a stackblitz demo:

https://stackblitz.com/edit/typescript-fs-validator-typescript-issue-reported?file=index.ts

class Person {
    @IsValueIn(['PETER', 'JAMES'])
    @IsAlpha()
    @IsDefined()
    public name:string;
}

When this demo is run it logs the following:

Error in /turbo_modules/@fireflysemantics/validator@3.0.10/bundles/fireflysemantics-validator.umd.js (194:21)
The ValidationContainer
already contains context with signature IsValueIn_Person_name.

This is because the runtime decorator @IsValueIn(['PETER', 'JAMES']) is called twice.

I've added logging statements to the @fireflysemantics/validator library such that this can be seen more clearly:

https://github.com/fireflysemantics/validator/blob/master/projects/validator/src/lib/ValidationContainer.ts#L61

That is the function that gets called by the decorator.

  /**
   * @param target Add a ValidationContext instance.
   * @throws Error if attempting to add a ValidationContext with a signature that duplicates that of an instance already contained.
   * 
   * If an exception thrown it indicates that a duplicate class definition exist
   * in the runtime.  In other words the same class definition is loaded more
   * than once because it exists in multiple files.
   * 
   */
  public static addValidationContext(target: ValidationContext): void {

    const key: string = getPropertyKey(
      target.target.name,
      target.propertyName
    );

    console.log("The property key is: ", key)
    console.log("The target signature is: ", target.getSignature())

Expected behavior:
These statements should only execute one time for each decorator:

    console.log("The property key is: ", key)
    console.log("The target signature is: ", target.getSignature())

Actual behavior:

However they get called twice for the @IsValueIn(['PETER', 'JAMES']) decorator.

Try commenting out @IsValueIn(['PETER', 'JAMES']) and you will see there are no exceptions.

Playground Link:

https://stackblitz.com/edit/typescript-fs-validator-typescript-issue-reported?file=index.ts

[fireflysemantics]

Also asked about this on SO just in case it produces additional insight.

https://stackoverflow.com/questions/62866171/typescript-decorator-gets-called-twice

[fireflysemantics]

Closing - Error in the decorator. See the SO Issue if you need an explanation:

https://stackoverflow.com/questions/62866171/typescript-decorator-gets-called-twice