I want to delete a file and wait for the deletion to succeed before moving forward. I have used unlink function inside a promise to get the result, but when unlink done successfully then I am getting the result from the promise if there is any kink of error while deleting the file the promise does not return any error.
Service:
public removeUserImage(
user: User,
): Promise<NodeJS.ErrnoException | boolean> {
const pathToRemoveImage = 'src/public/uploads'+ '/' + user.image_url;
return new Promise((resolve, reject) => {
unlink(pathToRemoveImage, (error) => {
if (error) reject(error);
resolve(true);
});
});
}
Controller:
const isFileRemoved = await this._userService.removeUserImage(user);
//This block not excuting
if (!isFileRemoved) {
throw new InternalServerErrorException(
'Error occurred while trying to remove file.',
);
}
Your promise rejects if there's an error. When using await, you need to wrap the code in try..catch in order to handle any failures
try {
await this._userService.removeUserImage(user);
} catch (err) {
console.error(err);
throw new InternalServerErrorException(
'Error occurred while trying to remove file.'
);
}
FYI, you can (and should) use the Promises API versions of the fs functions
import { unlink } from "node:fs/promises";
public removeUserImage({ image_url }: User): Promise<void> {
const pathToRemoveImage = `src/public/uploads/${image_url}`;
return unlink(pathToRemoveImage);
}
If you wanted your method to always resolve with a Boolean, you'd want something like
return unlink(pathToRemoveImage)
.then(() => true) // resolve with "true" for success
.catch((err) => {
console.error("removeUserImage", image_url, err);
return false; // resolve with "false" for failure
});
The error will always go to catch block,
try {
await this._userService.removeUserImage(user);
} catch (err) {
console.error(err);
throw new InternalServerErrorException(
'Error occurred while trying to remove file.'
);
}
Suggestion: You don't need to convert unlink(callback) to promise fs has promise function also, check this
const fs = require('fs');
const fsPromises = fs.promises;
public removeUserImage(
user: User,
): Promise<void> {
const pathToRemoveImage = 'src/public/uploads'+ '/' + user.image_url;
return fsPromises.unlink(pathToRemoveImage);
}