Accept null file_size in AttachmentDto

[gpunto]

Goal

It seems that backend can return null for file_size on attachments, but AttachmentDto.file_size was non-nullable so explicit nulls in the JSON caused deserialization to fail.

This also aligns with iOS, where AttachmentFile decodes a missing or non-decodable file_size as 0.

Closes #6428

Implementation

• AttachmentDto.file_size is now Int?, so an explicit null from the API deserializes cleanly.
• DomainMapping maps null to 0 when mapping to the domain Attachment.fileSize.

Testing

• New unit test Deserialize JSON attachment with null file_size covers the parser path.
• Existing attachment parser and mapping tests continue to pass.

Summary by CodeRabbit

• Bug Fixes

  • Improved attachment data handling by making file size processing null-safe. When file size information is unavailable, the system now defaults to zero instead of propagating null values, ensuring more robust behavior.

• Tests

  • Expanded test coverage with new test cases validating correct deserialization and mapping of attachments when file size values are null or missing.

[github-actions]

PR checklist ✅

All required conditions are satisfied:

• Title length is OK (or ignored by label).
• At least one pr: label exists.
• Sections ### Goal, ### Implementation, and ### Testing are filled, or the PR is bot-authored.
• An issue is linked (Linear ticket or GitHub issue), or the PR is bot-authored.

🎉 Great job! This PR is ready for review.

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-chat-android-client	5.82 MB	5.82 MB	0.00 MB	🟢
stream-chat-android-ui-components	11.02 MB	11.02 MB	0.00 MB	🟢
stream-chat-android-compose	12.42 MB	12.42 MB	0.00 MB	🟢

[coderabbitai]

Walkthrough

This PR makes AttachmentDto.file_size nullable to handle API responses with explicit null values. The DTO now coerces null to 0 during domain mapping, and deserialization tests verify the behavior with new null-file-size fixtures.

Changes

Attachment file_size nullable handling

Layer / File(s)	Summary
DTO contract and domain mapping stream-chat-android-client/src/main/java/io/getstream/chat/android/client/api2/model/dto/AttachmentDto.kt, stream-chat-android-client/src/main/java/io/getstream/chat/android/client/api2/mapping/DomainMapping.kt, stream-chat-android-client/src/test/java/io/getstream/chat/android/client/api2/mapping/DomainMappingTest.kt	AttachmentDto.file_size is now Int? (default 0). The mapping applies null-safe coercion (file_size ?: 0) when converting to domain Attachment. Test expectation updated to validate the mapping behavior.
Test coverage for null file_size stream-chat-android-client/src/test/java/io/getstream/chat/android/client/parser2/testdata/AttachmentDtoTestData.kt, stream-chat-android-client/src/test/java/io/getstream/chat/android/client/parser2/AttachmentDtoAdapterTest.kt	New test fixtures (jsonWithNullFileSize, attachmentWithNullFileSize) and deserialization test verify that null file_size in JSON is correctly parsed to the expected DTO with null field.

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🎯 2 (Simple) | ⏱️ ~8 minutes

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🐰 A nullable file, oh what a sight!
Once broken by null, now fixed just right.
The API sends nothing, and we don't despair,
Zero by default—a null-safe affair! 🎉

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: making AttachmentDto.file_size accept null values instead of requiring a non-null integer.
Description check	✅ Passed	The description includes Goal and Implementation sections explaining the change, test coverage, and alignment with iOS. However, it lacks UI Changes section (not applicable), Testing details (partially covered), and incomplete Contributor/Reviewer checklists.
Linked Issues check	✅ Passed	All requirements from issue #6428 are met: AttachmentDto.file_size is now nullable (Int?), domain mapping coerces null to 0, and new unit tests verify deserialization of null file_size.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to resolving issue #6428: making file_size nullable in the DTO, updating domain mapping, and adding tests for the null case.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch null-file-size

Warning

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[coderabbitai]

🧹 Nitpick comments (1)

stream-chat-android-client/src/test/java/io/getstream/chat/android/client/api2/mapping/DomainMappingTest.kt (1)

550-577: ⚡ Quick win

Consider adding an explicit test case for null file_size mapping.

While the current test correctly handles the nullable field with ?: 0, adding a dedicated test case that explicitly creates an AttachmentDto with file_size = null and verifies it maps to fileSize = 0 would improve coverage and documentation of this behavior.

Suggested test case

`@Test`
fun `AttachmentDto with null file_size is mapped to Attachment with fileSize 0`() {
    val attachmentDto = randomAttachmentDto().copy(file_size = null)
    val sut = Fixture().get()
    val attachment = with(sut) { attachmentDto.toDomain() }
    attachment.fileSize shouldBeEqualTo 0
}

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In
`@stream-chat-android-client/src/test/java/io/getstream/chat/android/client/api2/mapping/DomainMappingTest.kt`
around lines 550 - 577, Add a focused unit test that verifies null file_size on
AttachmentDto maps to 0 on Attachment: create an AttachmentDto via
randomAttachmentDto().copy(file_size = null), call toDomain() using the same
Fixture().get() setup, and assert the resulting Attachment.fileSize equals 0;
reference AttachmentDto, file_size, Attachment, fileSize, toDomain,
randomAttachmentDto and Fixture().get() when locating where to add the test.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In
`@stream-chat-android-client/src/test/java/io/getstream/chat/android/client/api2/mapping/DomainMappingTest.kt`:
- Around line 550-577: Add a focused unit test that verifies null file_size on
AttachmentDto maps to 0 on Attachment: create an AttachmentDto via
randomAttachmentDto().copy(file_size = null), call toDomain() using the same
Fixture().get() setup, and assert the resulting Attachment.fileSize equals 0;
reference AttachmentDto, file_size, Attachment, fileSize, toDomain,
randomAttachmentDto and Fixture().get() when locating where to add the test.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 73788c53-f8bf-4bea-bb96-fca808185220

📥 Commits

Reviewing files that changed from the base of the PR and between acf931d and e4d7725.

📒 Files selected for processing (5)

• stream-chat-android-client/src/main/java/io/getstream/chat/android/client/api2/mapping/DomainMapping.kt
• stream-chat-android-client/src/main/java/io/getstream/chat/android/client/api2/model/dto/AttachmentDto.kt
• stream-chat-android-client/src/test/java/io/getstream/chat/android/client/api2/mapping/DomainMappingTest.kt
• stream-chat-android-client/src/test/java/io/getstream/chat/android/client/parser2/AttachmentDtoAdapterTest.kt
• stream-chat-android-client/src/test/java/io/getstream/chat/android/client/parser2/testdata/AttachmentDtoTestData.kt

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[stream-public-bot]

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