feat: add highlight_type to files.completeUploadExternal and filesUploadV2

[zimeg]

This pull request adds highlight_type support to files.completeUploadExternal and the filesUploadV2 method.

The highlight_type parameter allows specifying the file type hint for uploads (e.g. png, jpg, gif), enabling optimistic rendering before the async upload processing job completes.

📚 https://docs.slack.dev/reference/methods/files.completeUploadExternal

Changes

• Added highlightType to FilesCompleteUploadExternalRequest.FileDetails (per-file in the files array)
• Added highlightType to FilesUploadV2Request (top-level for single-file uploads) and FilesUploadV2Request.UploadFile (for multi-file uploads)
• Updated MethodsClientImpl.filesUploadV2 to pass highlightType through to each FileDetails object in the completion step

Usage

importcom.slack.api.Slack;
importcom.slack.api.methods.response.files.FilesUploadV2Response;
Slackslack = Slack.getInstance();
// Single file upload with highlight_typeFilesUploadV2Responseresponse = slack.methods(token).filesUploadV2(r -> r
.channel("C0123456789")
.file(newFile("./image.png"))
.filename("image.png")
.title("Image Upload")
.highlightType("png")
.initialComment("Uploaded with highlight_type for optimistic rendering")
);
// Multiple file uploads with highlight_typeFilesUploadV2Responseresponse = slack.methods(token).filesUploadV2(r -> r
.channel("C0123456789")
.uploadFiles(Arrays.asList(
FilesUploadV2Request.UploadFile.builder()
.file(newFile("./photo.jpg"))
.filename("photo.jpg")
.title("Photo")
.highlightType("jpg")
.build(),
FilesUploadV2Request.UploadFile.builder()
.file(newFile("./diagram.png"))
.filename("diagram.png")
.title("Diagram")
.highlightType("png")
.build()
))
.initialComment("Multiple files with highlight_type")
);

Related PRs

• Node SDK: feat(web-api): add highlight_type to files.completeUploadExternal and filesUploadV2 node-slack-sdk#2594
• Python SDK: feat: add highlight_type to files.completeUploadExternal and files_upload_v2 python-slack-sdk#1875

Category (place an x in each of the [ ])

• bolt (Bolt for Java)
• bolt-{sub modules} (Bolt for Java - optional modules)
• slack-api-client (Slack API Clients)
• slack-api-model (Slack API Data Models)
• slack-api-*-kotlin-extension (Kotlin Extensions for Slack API Clients)
• slack-app-backend (The primitive layer of Bolt for Java)

Requirements

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.25%. Comparing base (fc11ab4) to head (aa896a4).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
.../com/slack/api/methods/impl/MethodsClientImpl.java	0.00%	2 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #1589 +/- ##
============================================
- Coverage 73.29% 73.25% -0.04% + Complexity 4519 4516 -3 
============================================
Files 478 478 Lines 14298 14300 +2 Branches 1490 1490 ============================================
- Hits 10480 10476 -4 - Misses 2930 2935 +5 - Partials 888 889 +1 

Flag	Coverage Δ
jdk-14	73.25% <0.00%> (-0.04%)	⬇️

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[srtaalej]

⭐ ⭐ ⭐

[zimeg]

@srtaalej Kind thanks 📠 Let's get this merged? Let's!