Good start on the move function. However, the task requirements point towards an asynchronous implementation. You are expected to use promise-based methods like fs.promises.stat() and fs.promises.unlink().

Consider refactoring this function to be an async function. This will allow you to use await to handle asynchronous operations cleanly and is a best practice in Node.js to avoid blocking the event loop with synchronous I/O operations like fs.statSync or fs.renameSync.

The task requires that an error must be thrown if the source file does not exist. Currently, you are logging a message to console.error and then returning from the function.

While this informs the user, it doesn't behave like a thrown error (e.g., it results in a successful process exit code 0). Please change this to throw new Error('Non-existent source file');. This applies to all the error conditions in your code.

This check for the destination directory has a logical flaw. If destinationFile is a path like 'non-existent-dir/', path.dirname('non-existent-dir/') resolves to '.' (the current directory), which almost always exists. This check will pass, but the fs.renameSync call later will fail with an unhandled error because the directory doesn't exist.

You need a more robust way to validate the destination path. If destinationFile ends with a path separator, you should check if that path itself exists and is a directory.

This is the most critical issue. The task requires the "move" operation to be implemented as a two-step process:

1. Copy the source file to the destination using streams (fs.createReadStream piped to fs.createWriteStream).
2. Delete the original source file using fs.promises.unlink() only after the copy is successful.

Using fs.renameSync does not meet these specific technical requirements. You'll need to replace all instances of fs.renameSync with the stream-based copying logic followed by unlinking the source file.

The task requires using the asynchronous fs.promises API for all file system operations. Please import it instead of the synchronous fs module. You can achieve this by changing this line to const fs = require('fs').promises;.

To correctly use the fs.promises API, this function should be declared as async. This will allow you to use await with the promise-based methods, making the code non-blocking and easier to read. For example: async function move() { ... }.

The requirements state that your application must throw an error in failure cases, not just log to the console. This is crucial for error handling in larger applications and for testing. Please replace the console.error and return with throw new Error('Non-existent source file');. This change should be applied to all error checks in this file.

As mentioned in the previous review, using fs.renameSync is not permitted for this task. The goal is to implement the move operation manually by copying the file and then deleting the original.

You should implement this by:

1. Creating a read stream for the source file (fs.createReadStream).
2. Creating a write stream for the destination file (fs.createWriteStream).
3. Using stream.pipeline to connect them, which handles the data transfer and error handling properly.
4. After the pipeline successfully completes, deleting the source file using await fs.unlink(sourceFile).

In addition to using the forbidden fs.renameSync method, there's a logical error in how the destination path is constructed here.

path.dirname(normalizedSource) resolves to the directory of the source file, not the destination. This means your code would attempt to rename the file within its original folder instead of moving it to the target location.

For example, mv ./dir1/fileA.txt ./dir2/fileB.txt would incorrectly result in ./dir1/fileB.txt instead of the expected ./dir2/fileB.txt. The correct destination for the new file is already available in your normalizedDest variable.

The task requires using the promise-based fs module. You should import it like this: const fs = require('fs').promises;. This will give you access to asynchronous methods that you can use with await.

Since you'll be using await with methods from fs.promises, this function needs to be declared as async. For example: async function move() { ... }.

As mentioned in the previous review, the application must throw an error when something goes wrong, not just log to the console. This allows the calling code (or the Node.js runtime) to know that the operation failed. Please replace this with throw new Error('...');. This applies to all error handling in this file.

This is a synchronous call. The requirements state that you must use the fs.promises API for file system operations. After importing fs.promises, you could check for file existence asynchronously. A common way is to try to access it and catch any error. For example: try { await fs.access(sourceFile); } catch { throw new Error('Non-existent source file'); }.

There are two issues here. First, this is a synchronous call and should be replaced with an asynchronous one from fs.promises. Second, this logic is incorrect for destination paths that end with a separator, like nonexistent/. In that case, path.dirname returns . which always exists, and your check fails to catch that the nonexistent directory is missing. You'll need to handle this case specifically before attempting the move.

This is the most critical part of the feedback. The task explicitly forbids using fs.rename() or fs.renameSync. The 'move' operation must be implemented by:

1. Creating a readable stream from the sourceFile using fs.createReadStream().
2. Creating a writable stream to the new destination path using fs.createWriteStream().
3. Piping the read stream to the write stream to copy the file content.
4. Once the copy is complete (you can wrap the stream logic in a Promise), you must delete the original sourceFile using await fs.unlink(sourceFile).

Please replace all fs.renameSync calls with this stream-based copy-and-delete logic.