Angular pipe to suppress sensitive information

Question

I have created an Angular pipe to suppress the sensitive information like credit cards, bank account, ABA numbers etc.

This is working fine but I would like to know if this is the best possible way to implement the logic.

Here is the Typescript code for pipe logic.

export class SuppressInfoPipe implements PipeTransform {
 transform(valueToSupress: string, unSuppressedCount?: number): string {
 let suppressedOutput = '';
 const valueToRemainUnsuppressed =
 valueToSupress.substring(valueToSupress.length - unSuppressedCount, valueToSupress.length);
 let astariskLength = valueToSupress.length - unSuppressedCount;
 for ( let i = 0; i < astariskLength; i++) {
 suppressedOutput = suppressedOutput.concat('*');
 }
 suppressedOutput = suppressedOutput.concat(valueToRemainUnsuppressed);
 return suppressedOutput;
 }
}

it takes the string input and the number of character they will no be hidden and then return the suppressed output.

Comments and suggestions are welcomed.

Answer 1

I would avoid the for loop to generate the "suppressed string".

My approach would be:

export class SuppressInfoPipe implements PipeTransform {
 transform(valueToSupress: string, unSuppressedCount = 0): string {
 const suppressedCount = valueToSupress.length - unSuppressedCount;
 const valueToRemainUnsuppressed =
 valueToSupress.substring(suppressedCount, valueToSupress.length);
 return Array(suppressedCount + 1).join('*') + valueToRemainUnsuppressed; // suppressedCount + 1: since join will a string of length "suppressedCount"
 }
}

In this case:

Array(n) will return an array of length n.

enter image description here

.join("*") will join the list and return a string equivalent of length n-1.

• Muhammad Ahsan: That's much better. Only thing I want to confirm is this changing the type of Array object when returning just like JavaScript does to variables depending upon the data being assigned ?
• Sree.Bh: Updated my answer.
• Muhammad Ahsan: I got your point :) . Thanks for adding explanation to your answer.