how to use the appendfilesync function from the fs-extra library in typescript

To use appendFileSync function from fs-extra library in TypeScript, we need to first install both fs-extra and @types/fs-extra packages.

npm install --save fs-extra
npm install --save-dev @types/fs-extra
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Once the packages are installed, we can import the appendFileSync function from fs-extra in our TypeScript file and use it as follows:

index.ts
import { appendFileSync } from 'fs-extra';

const filePath = 'path/to/file.txt';
const data = 'new data to append to the file';

appendFileSync(filePath, data);
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Here, appendFileSync function takes two arguments:

1. filePath - a string representing the file path that we want to append the data to.
2. data - a string or a buffer containing the data that we want to append to the file.

This function appends the data to the end of the specified file and returns undefined.

Note: While using appendFileSync, we should make sure that the file path exists, otherwise, it will throw an error.