file.exists() is always true

[yairopro]

[REQUIRED] Environment info

firebase-tools: 9.18.0

Platform: macOS

[REQUIRED] Test case

The storage emulator within an executed script (with exec commande) is inconsistant because the emulator will always return that any file is existant, whatever file name you give him.

[REQUIRED] Steps to reproduce

Execute the following snippet within the emulator (storage emulator needed). The output will always be true.

// firebase emulators:exec test.js

const admin = require('firebase-admin');
admin.initializeApp({ storageBucket: 'default-bucket' });
const bucket = admin.storage().bucket();
const file = bucket.file(`/inexistantFile`);
const [exists] = await file.exists();
console.log('inexistantFile: ', exists); // exists will always be true

[REQUIRED] Expected behavior

The emulator to be consistant. The File.exists()method should returns false when a file was never created or deleted.

[REQUIRED] Actual behavior

The File.exists() method always returns true even for non existing files.

[abeisgoat]

This is actually outside the current scope of the emulator as the exists() method is not one we guarantee to be correct atm. We're working on extending Google Cloud API support, so hopefully this will function correctly in the near future.

[yairopro]

Thanks for this information.
How can I know which storage methods / features are supported by the emulator (guaranteed to be correct )? please

[rhodgkins]

I had similar problems so implemented various missing features of the Storage emulator - its still waiting to be merged :-/
You could try working against this and see if it fixes your problem and try upvoting / commenting on the PR.

[schankam]

Use it that way: const [fileExist] = await file.exists();

[minhdanh]

It's weird that I'm seeing this on production Firebase storage, not emulator. I check if a file exists first before deleting it:

      const fileRef = getStorage().bucket("my-bucket").file(userId + "/" + transactionId + "/" + fileName);
      if (await fileRef.exists()) {
        logger.info("Attachment file exist in storage bucket. Deleting attachment file");
        await fileRef.delete();
      }

The file does not exist, but the check passed and resulted to an error: