Fix image dataset caption paths with repeated extensions

[LittleYier]

The image-text dataset loader replaces every occurrence of the image extension when locating captions. For example, train.png/photo.png looks for train.txt/photo.txt, silently returning an empty caption instead of reading train.png/photo.txt.

Replace only the final extension, matching the video-text dataset loader. Tests cover extension text in directories and filenames, uppercase extensions, repeated dataset folders, and missing captions.

Verified with real image/caption files and the full unit suite: 1,796 passed, 12 skipped. Ruff passes.

Fixes #16213

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[Copilot]

🟢 Approval recommended

The change is minimal, directly addresses the reported bug, and is backed by targeted unit tests covering the relevant edge cases.

Pull request overview

Fixes incorrect caption-file resolution in the image-text dataset loader when the image extension appears earlier in the path (e.g., folder names like train.png/ or filenames like image.png.crop.png). The change aligns caption lookup with “replace only the final extension” behavior and adds focused unit coverage for the edge cases described in #16213.

Changes:

• Update caption path construction to replace only the final image extension (os.path.splitext(...)[0] + ".txt").
• Add unit tests covering extensions in directory names, repeated extensions in filenames, uppercase extensions, kohya-style repeat folders, and missing captions.

File summaries

File	Description
comfy_extras/nodes_dataset.py	Fix caption path derivation to only swap the final extension, preventing misresolution like train.txt/photo.txt.
tests-unit/comfy_extras_test/nodes_dataset_test.py	Add parameterized tests validating correct caption lookup across tricky path/extension cases and missing-caption behavior.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite

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📝 Walkthrough

Walkthrough

The dataset loader now derives caption file paths by replacing only the final image extension. This preserves captions when an extension appears in a directory name or earlier in a filename. New parametrized tests cover these paths, nested repeated images, caption content, and missing caption files.

Priority: ➖ Normal

Severity of issue fixed: Medium

Merge Risk: 🔵 Low · up to cbd75

This updates image-caption lookup to replace only the final extension, but the nested repeat-folder test expects one result where the loader returns two. The test assertion must be corrected before merge.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 2 files.	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 describes the main change: fixing caption paths when image extensions repeat in paths or filenames.
Description check	✅ Passed	The description explains the existing failure, the final-extension fix, affected examples, tests, and verification results.
Linked Issues check	✅ Passed	The change satisfies issue #16213 by replacing only the final image extension when locating adjacent .txt captions. The added tests cover repeated path or filename extensions and missing captions.
Out of Scope Changes check	✅ Passed	The changes are limited to the caption-path fix and focused unit tests. No unrelated code changes are present.

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Actionable comments posted: 1

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Inline comments:
In `@tests-unit/comfy_extras_test/nodes_dataset_test.py`:
- Line 80: Update the repeat-count expectation in the affected dataset test to
derive from the first path component, so nested paths such as
2_subject/image.png.crop.png expect two images and captions; alternatively,
parameterize the expected count for each case while preserving coverage of
missing-caption fallback behavior.

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📒 Files selected for processing (2)

• comfy_extras/nodes_dataset.py
• tests-unit/comfy_extras_test/nodes_dataset_test.py

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⚠️ CI failures not shown inline (2)

GitHub Actions: CLA Assistant / 0_cla-assistant.txt: Fix image dataset caption paths with repeated extensions

Conclusion: failure

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##[group]Run contributor-assistant/github-action@ca4a40a7d1004f18d9960b404b97e5f30a505a08
 with:
   lock-pullrequest-aftermerge: false
   path-to-document: https://github.com/Comfy-Org/comfy-cla/blob/main/comfyui_icla.md
   remote-organization-name: comfy-org
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   branch: main
   allowlist: action@github.com,actions-user,ampagent,claude,comfy-pr-bot,GitHub Action,github-actions,github-actions[bot],Glary Bot,Glary-Bot,*[bot]
   custom-notsigned-prcomment: 🎉 Thank you for your contribution, we really appreciate it! 🎉
Like many open source projects, we require contributors to sign our [Contributor License Agreement (CLA)](https://github.com/Comfy-Org/comfy-cla/blob/main/comfyui_icla.md). A CLA makes the ownership of contributions explicit, so contributors and the project share a clear understanding of how the code can be used. By signing, you:
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✍ **To sign, please post a new comment on this PR with exactly the following text:** ✍
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   suggest-recheck: true
 env:
   GITHUB_***REDACTED_SECRET_ASSIGNMENT***
   PERSONAL_ACCESS_***REDACTED_SECRET_ASSIGNMENT***
 ##[endgroup]
 CLA Assistant GitHub Action bot has started the process
 (node:2150) [DEP0040] DeprecationWar...

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GitHub Actions: CLA Assistant / cla-assistant: Fix image dataset caption paths with repeated extensions

Conclusion: failure

View job details

##[group]Run contributor-assistant/github-action@ca4a40a7d1004f18d9960b404b97e5f30a505a08
 with:
   lock-pullrequest-aftermerge: false
   path-to-document: https://github.com/Comfy-Org/comfy-cla/blob/main/comfyui_icla.md
   remote-organization-name: comfy-org
   remote-repository-name: comfy-cla
   path-to-signatures: signatures/cla.json
   branch: main
   allowlist: action@github.com,actions-user,ampagent,claude,comfy-pr-bot,GitHub Action,github-actions,github-actions[bot],Glary Bot,Glary-Bot,*[bot]
   custom-notsigned-prcomment: 🎉 Thank you for your contribution, we really appreciate it! 🎉
Like many open source projects, we require contributors to sign our [Contributor License Agreement (CLA)](https://github.com/Comfy-Org/comfy-cla/blob/main/comfyui_icla.md). A CLA makes the ownership of contributions explicit, so contributors and the project share a clear understanding of how the code can be used. By signing, you:
- Confirm that you own your contribution.
- Keep the right to reuse your own code.
- Grant us a copyright license to include and share it within our projects.
CLAs are standard practice across major open source projects including those under the Apache Software Foundation and the Linux Foundation. Ours is based on the Apache Software Foundation's CLA. Most importantly, it would enable us to relicense the project under a more permissive license in the future, giving the project and its community greater flexibility.
✍ **To sign, please post a new comment on this PR with exactly the following text:** ✍
   custom-pr-sign-comment: I have read and agree to the Contributor License Agreement
   custom-allsigned-prcomment: ✅ All contributors have signed the CLA. Thank you! This PR is ready to be merged.
   use-dco-flag: false
   suggest-recheck: true
 env:
   GITHUB_***REDACTED_SECRET_ASSIGNMENT***
   PERSONAL_ACCESS_***REDACTED_SECRET_ASSIGNMENT***
 ##[endgroup]
 CLA Assistant GitHub Action bot has started the process
 (node:2150) [DEP0040] DeprecationWar...

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Community-contributed extra nodes.

⚙️ CodeRabbit configuration file

Files:

• comfy_extras/nodes_dataset.py

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⚙️ CodeRabbit configuration file

Files:

• tests-unit/comfy_extras_test/nodes_dataset_test.py
• comfy_extras/nodes_dataset.py

Documentation and README edits should be concise, factual, and tied to the changed behavior.

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• comfy_extras/nodes_dataset.py

🔇 Additional comments (1)

comfy_extras/nodes_dataset.py (1)

267-267: LGTM!

[LittleYier]

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