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fix(core): correctly consolidate multi-part text content
google-gemini/gemini-cliGitHub
Merged 3 months agoAugust 22, 2025
Related#4053

This pull request refactors the content consolidation logic in GeminiChat to correctly merge multi-part text content, especially during streaming responses.

What was done

  • Updated the content consolidation logic within the GeminiChat class for streaming responses to ensure text is appended to the correct part.
  • Changed the text appending mechanism from the first part to the last part of existing content when merging.
  • Introduced new private helper methods, isFirstPartText and isLastPartText, to precisely check the type and position of text content within multi-part responses.
  • The packages/core/src/core/geminiChat.ts file was modified to implement these changes, improving the accuracy of text merging.

Impact

  • Ensures accurate merging of text into multi-part content, preventing incorrect concatenation of text within streaming responses.
  • Addresses scenarios where streaming responses contain mixed content types, requiring careful and precise text merging.
  • Improves the robustness of content parsing within Gemini chat interactions, reducing potential data corruption or malformed responses.

Technical details

  • The consolidateStreamingContent method in GeminiChat was updated to utilize the new isFirstPartText and isLastPartText helpers.
  • The isFirstPartText helper now explicitly checks if the first part of a content object is a text string and excludes non-text part types like functionCall, inlineData, etc.
  • The isLastPartText helper was added to verify if the last part of a content object is a text string, also ensuring it's for a 'model' role and excluding non-text part types.
  • Text merging now targets lastContent.parts[lastContent.parts.length - 1].text instead of lastContent.parts[0].text when appropriate.
  • These changes were implemented in packages/core/src/core/geminiChat.ts.

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