feat: add blob support

[NJ-2020]

Details

Related Issues

$ Expensify/App#9402

Automated Tests

Unit tests were added to cover this fix.

Manual Tests

1. Apply this changes to E/App
2. Run & Open the App
3. Turn off your internet
4. Go to any report & upload any image
5. Make sure there are no errors
6. Refresh the App
7. Make sure the image is still loads correctly

Author Checklist

• I linked the correct issue in the ### Related Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android / native
  • Android / Chrome
  • iOS / native
  • iOS / Safari
  • MacOS / Chrome / Safari
  • MacOS / Desktop
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
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• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
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• I verified that if a function's arguments changed that all usages have also been updated correctly
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately and each prop has a /** comment above it */
  • The file is named correctly
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • If we are not using the full Onyx data that we loaded, I've added the proper selector in order to ensure the component only re-renders when the data it is using changes
  • For Class Components, any internal methods passed to components event handlers are bound to this properly so there are no scoping issues (i.e. for onClick={this.submit} the method this.submit should be bound to this in the constructor)
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  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
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Screenshots/Videos

Android: Native

Android: mWeb Chrome

9402_android_mweb.1.1.mp4

iOS: Native

iOS: mWeb Safari

Simulator.Screen.Recording.-.iPhone.15.-.2025-05-12.at.05.40.20.mp4

MacOS: Chrome / Safari

Screen.Recording.2025-05-12.at.06.39.56.mov

MacOS: Desktop

Screen.Recording.2025-05-11.at.22.45.56.1.mov

[github-actions]

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[parasharrajat]

Then we need a way to check whether it is a Blob. You can try to create a blob with this data and see it has same content as you originally passed.

[NJ-2020]

Done

[blimpich]

It looks like @deetergp is the CME for the linked issue, assigning him, and unassigning myself

[parasharrajat]

What type is returned from Onyx when we retrieve the Blob value?

[NJ-2020]

What type is returned from Onyx when we retrieve the Blob value?

The type value that is returned by Onyx is object, because when we storing blob value into IndexedDB, it will only store all the blob values & properties, but it's no longer an instance of the Blob constructor

See more at the last point: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm#things_that_dont_work_with_structured_clone

I think maybe the only we can check if the returned value is Blob or not by checking some properties in the returned object, but I am not sure if it's the best solution

[parasharrajat]

But then, how will we know that a collection in Onyx is of type Blob? We need something to differentiate, and we should return blobs from Onyx when we save Blobs.

[NJ-2020]

But then, how will we know that a collection in Onyx is of type Blob? We need something to differentiate, and we should return blobs from Onyx when we save Blobs.

Ok..., please HOLD this one, give me some time I'll look into this more deeper 👀 about this one

[parasharrajat]

Feel free to raise this on slack to get confirmation and idea on how Blob support should be implemented. They might have better suggestions.

[NJ-2020]

But then, how will we know that a collection in Onyx is of type Blob? We need something to differentiate, and we should return blobs from Onyx when we save Blobs.

Done, fixed

---

So basically before, when we set a value in Onyx like this one:

const blob = new Blob(["content"]);
Onyx.set("key", blob);
Onyx.get("key").then(res => console.log(res instanceof Blob)) // false

And we check if the value is instanceof blob it will return false, but if we do it like this, it will return true

const blob = new Blob(["content"]);
Onyx.set("key", {
    blobValue: blob
});

Onyx.get("key").then(res => console.log(res.blobValue instanceof Blob)) // true

It's because when we set a value on Onyx, it will remove any null values if the Onyx value is typeof object and not an array

react-native-onyx/lib/Onyx.ts

Line 201 in a7c1666

return Storage.setItem(key, valueWithoutNullValues)

react-native-onyx/lib/Onyx.ts

Line 188 in a7c1666

const valueWithoutNullValues = valueAfterRemoving as OnyxValue<TKey>;

react-native-onyx/lib/Onyx.ts

Line 174 in a7c1666

const {value: valueAfterRemoving, wasRemoved} = OnyxUtils.removeNullValues(key, value);

react-native-onyx/lib/OnyxUtils.ts

Lines 1156 to 1170 in a7c1666

	function removeNullValues<Value extends OnyxInput<OnyxKey> | undefined>(key: OnyxKey, value: Value, shouldRemoveNestedNulls = true): RemoveNullValuesOutput<Value> {
	if (value === null) {
	remove(key);
	return {value, wasRemoved: true};
	}
	if (value === undefined) {
	return {value, wasRemoved: false};
	}
	// We can remove all null values in an object by merging it with itself
	// utils.fastMerge recursively goes through the object and removes all null values
	// Passing two identical objects as source and target to fastMerge will not change it, but only remove the null values
	return {value: shouldRemoveNestedNulls ? utils.removeNestedNullValues(value) : value, wasRemoved: false};
	}

react-native-onyx/lib/utils.ts

Lines 108 to 115 in a7c1666

	function removeNestedNullValues<TValue extends OnyxInput<OnyxKey> | null>(value: TValue): TValue {
	if (typeof value === 'object' && !Array.isArray(value)) {
	const objectValue = value as Record<string, unknown>;
	return fastMerge(objectValue, objectValue) as TValue;
	}
	return value;
	}

So when we set blob value, and then we check if it's instance of blob it will return false, because some properties might be removed during set item function process

And also on the second example where we set the blob value like this, it returns true, it's because during the remove process, we only remove null values from the object itself, meaning it doesn't go to the child/grandchild properties, so when we check if it's instance of blob it will return true since there are no properties that are got removed

Onyx.set("key", {
    blobValue: blob
});

cc: @parasharrajat

[parasharrajat]

That's interesting. I think we then need to make some changes to overall architecture to allow storing blobs.

I do not want your research time to go in vain. We have a many expert contributors on slack which can suggest and improve your plan saving you time and bugs.

I would suggest that you summarize the whole plan of storing the attachments on all platforms and post it on Slack so that we can get this reviewed. You can later mentioned all the steps that you have already taken and challenges along the way.

This way we can optimize the solution and save us from increasing scope.

[NJ-2020]

I will be OOO this weekend 24 - 25 May, so I will back on 26 May

[parasharrajat]

@NJ-2020 is this needed? If not, let's close it.