feat(core): support DataBlock in all provider message converters

[Buktal]

AgentScope-Java Version

1.0.12 (development)

Description

DataBlock is documented as the forward-looking unified container for all binary modalities (image / audio / video / file), replacing the legacy ImageBlock / AudioBlock / VideoBlock subclasses. However, none of the provider message converters handled it — when a user built a message with DataBlock, every provider silently dropped the block and the LLM received no media content.

This PR fixes that gap.

Changes:

• URLSource: Add optional mimeType field for extension-less URLs (CDN signed URLs, API-generated media links). Backward-compatible — existing callers using the single-arg constructor or omitting mime_type in JSON are unaffected. MIME type resolution priority: Base64Source.mediaType > URLSource.mimeType > extension-based inference via MediaUtils.determineMediaType.

• DashScope: Add convertDataBlockToContentPart to DashScopeMediaConverter; add DataBlock branch to DashScopeMessageConverter (both convertToMultimodalContent and hasMediaContent / convertContentBlocks).

• Gemini: Add convertToInlineDataPart(DataBlock) to GeminiMediaConverter; add DataBlock branch in GeminiMessageConverter; fix extractSourceFromBlock which previously threw on DataBlock.

• Anthropic: Add convertDataBlock to AnthropicMediaConverter (image-only — Anthropic SDK does not expose a generic binary content block param); add DataBlock branch to AnthropicMessageConverter.

• OpenAI: Add DataBlock branch to OpenAIMessageConverter (routes to image / audio / video based on MIME prefix); add resolveMimeType utility to OpenAIConverterUtils.

How to test:

Msg msg = Msg.builder()
    .role(MsgRole.USER)
    .content(DataBlock.builder()
        .source(URLSource.builder()
            .url("https://example.com/photo.jpg")
            .build())
        .build())
    .content(TextBlock.builder().text("Describe this image").build())
    .build();

Previously the image was silently dropped; now it is routed correctly to each provider's image slot.

For extension-less URLs:

URLSource.builder()
    .url("https://cdn.example.com/media/abc123")
    .mimeType("video/mp4")
    .build()

Closes #1932

Checklist

• Code has been formatted with mvn spotless:apply
• All tests are passing (mvn test)
• Javadoc comments are complete and follow project conventions
• Related documentation has been updated (e.g. links, examples, etc.)
• Code is ready for review

[codecov]

Codecov Report

❌ Patch coverage is 43.97906% with 107 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...model/openai/formatter/OpenAIMessageConverter.java	0.00%	30 Missing ⚠️
...formatter/dashscope/DashScopeMessageConverter.java	0.00%	15 Missing and 1 partial ⚠️
...anthropic/formatter/AnthropicMessageConverter.java	0.00%	11 Missing and 1 partial ⚠️
...s/model/openai/formatter/OpenAIConverterUtils.java	0.00%	12 Missing ⚠️
...s/model/gemini/formatter/GeminiMediaConverter.java	67.85%	4 Missing and 5 partials ⚠️
...model/gemini/formatter/GeminiMessageConverter.java	0.00%	6 Missing and 1 partial ⚠️
...entscope/core/formatter/AbstractBaseFormatter.java	0.00%	5 Missing ⚠️
...e/formatter/dashscope/DashScopeMediaConverter.java	82.75%	2 Missing and 3 partials ⚠️
...l/anthropic/formatter/AnthropicMediaConverter.java	87.17%	2 Missing and 3 partials ⚠️
...del/gemini/formatter/GeminiConversationMerger.java	0.00%	5 Missing ⚠️
... and 1 more

📢 Thoughts on this report? Let us know!

[itxaiohanglover]

Good addition! Supporting DataBlock in all provider formatters ensures consistent handling across providers. The hasMediaContent check and convertToolResultToString updates are thorough.