bug(firestore): Timestamp values

[Paganiniana]

Plugin(s)

• Analytics
• App
• App Check
• Authentication
• Crashlytics
• Cloud Firestore
• Cloud Messaging
• Performance
• Remote Config

Did you test the latest version?

• I use the latest version

Platform(s)

• Android
• iOS
• Web

Current behavior

If I read a document using the FirebaseFirestore.getDocument method, its snapshot.data object is completely missing any value that resolves as a Firestore Timestamp value. For example, a document of the following format in Firebase ...

const docData = {
     author: "Some Name",
     description: "Some description",
     creationDate: <some timestamp>,
}

... is returned as ...

const docData = {
     author: "Some Name",
     description: "Some description",
}

Expected behavior

I would expect that any snapshot.data value has certain values in Firestore, it this method would return those values as part of its resolved object structure.

Reproduction

https://github.com/Paganiniana/capawesome-bug-reproduction

Steps to reproduce

(See the readme)

1. build project
2. run on local web server
3. run on an iOS device
4. observe difference in console logs

Other information

No response

Capacitor doctor

💊 Capacitor Doctor 💊

Latest Dependencies:

@capacitor/cli: 5.5.0
@capacitor/core: 5.5.0
@capacitor/android: 5.5.0
@capacitor/ios: 5.5.0

Installed Dependencies:

@capacitor/android: not installed
@capacitor/cli: 5.5.0
@capacitor/ios: 5.5.0
@capacitor/core: 5.5.0

[success] iOS looking great! 👌

Before submitting

• I understand that incomplete issues (e.g. without reproduction) are closed.

[Paganiniana]

In poking around the codebase, I've narrowed down the problem to the FirebaseFirestoreHelper.swift file. It seems the createJSValue method returns nil for instances of Timestamp. I'm manually marking its type and passing up its value as a second/nano second pair. In the JS layer, I'm passing these to the timestamp constructor, making it work just like the web client. If we could make these changes in firestore/src/index.ts and wrap the necessary read/write methods to pass this information back and forth from the native/web layers, that would be great!

[robingenz]

Thank you for reporting this issue! Would you be willing to create a PR with your idea? I would then take a closer look.

[Paganiniana]

Sure thing, @robingenz . I'll see if I can get that together, this morning.

[SureshKumarToverto]

@robingenz Could you please provide any updates on this matter or offer an estimated timeframe for resolving the issue? Thank you.

1. How to save date in Angular as a timestamp to Firestore #564
2. Issue #474 #475

[robingenz]

@SureshKumarToverto As already mentioned in #564 (comment), this is currently a bug in Capacitor (see ionic-team/capacitor#7252). I have to wait until it's fixed.

[johnmckay-reward]

@robingenz does this same bug also affect geopoints? we store both timestamps and geopoints in our firestore db, everything comes back fine when testing in the browser, but when we compile into a native iOS app and test on the device, neither timestamps/geopoints come back

[robingenz]

@johnmckay-reward No, this should be another issue. Please create a separate bug report.

[mdean808]

Is there a workaround for this bug while waiting for the capacitor team to fix ionic-team/capacitor#7252, or should I switch to storing my dates as strings as opposed to the Timestamp type in firestore to avoid this issue?

[robingenz]

No, there is currently no workaround. I have another idea on how to solve this, but of course I would prefer the problem to be solved in the Capacitor Core. I currently save all timestamps as ISO 8601 strings.

[u12206050]

Any update, this is pretty crucial I would think to any app using firestore?

[robingenz]

No, there are no updates yet. It's still on my to-do list for this year. For the time being, I recommend saving all timestamps as ISO 8601 strings.

[gdrose]

I'm still facing the same issue (on iOS). Are there any updates regarding this?

[beonde]

Saving the dates as strings to Firestore is not ideal as you will lose querying functionality that is possible with timestamp fields.

In the meantime I have made a local patch package to update the swift files to handle timestamps and output them as ISO 8601 strings from the plugin instead of null. Then it is easy to convert to a javascript date object from there.

The helper struct I have defined in swift looks like this:

import FirebaseFirestore

struct FirestoreHelper {
    static func convertTimestampsInDocument(data: [String: Any]) -> [String: Any] {
        var convertedData = [String: Any]()
        
        for (key, value) in data {
            if let timestamp = value as? Timestamp {
                // Convert Timestamp to Date
                let date = timestamp.dateValue()
                // Use the Date extension to convert Date to ISO 8601 string
                convertedData[key] = date.toISO8601String()
            } else if let nestedData = value as? [String: Any] {
                // Recursively convert nested dictionaries
                convertedData[key] = convertTimestampsInDocument(data: nestedData)
            } else {
                convertedData[key] = value
            }
        }
        
        return convertedData
    }
}

extension Date {
    func toISO8601String() -> String {
        let formatter = ISO8601DateFormatter()
        formatter.timeZone = TimeZone(secondsFromGMT: 0) // Set to UTC for consistency
        return formatter.string(from: self)
    }
}

The I was able to modify each toJSObject() method for the Results classes like so:

    public func toJSObject() -> AnyObject {
        // Convert the Firestore timestamps
        let rawData = documentSnapshot.data() ?? [:]
        let convertedData = FirestoreHelper.convertTimestampsInDocument(data: rawData)

        let snapshotDataResult = FirebaseFirestoreHelper.createJSObjectFromHashMap(convertedData)

        var snapshotResult = JSObject()
        snapshotResult["id"] = documentSnapshot.documentID
        snapshotResult["path"] = documentSnapshot.reference.path
        if let snapshotDataResult = snapshotDataResult {
            snapshotResult["data"] = snapshotDataResult
        } else {
            snapshotResult["data"] = NSNull()
        }

        var metadata = JSObject()
        metadata["fromCache"] = documentSnapshot.metadata.isFromCache
        metadata["hasPendingWrites"] = documentSnapshot.metadata.hasPendingWrites
        snapshotResult["metadata"] = metadata

        var result = JSObject()
        result["snapshot"] = snapshotResult
        return result as AnyObject
    }

Hope that helps as a temporary solution and maybe can assist towards a permanent solution too.

[beonde]

In poking around the codebase, I've narrowed down the problem to the FirebaseFirestoreHelper.swift file. It seems the createJSValue method returns nil for instances of Timestamp. I'm manually marking its type and passing up its value as a second/nano second pair. In the JS layer, I'm passing these to the timestamp constructor, making it work just like the web client. If we could make these changes in firestore/src/index.ts and wrap the necessary read/write methods to pass this information back and forth from the native/web layers, that would be great!

This is actually a much more efficient place to put the conversion. I think I will adjust my implementation to match this. That way you only need to iterate over the fields in a document once instead of twice.