fix: resolve lego task instruction mismatch causing noise output

[ChuxiJ]

Summary

• Fix _resolve_instruction() to fall back to task-specific instruction when the instruction field is empty/blank, not just when it exactly matches DEFAULT_DIT_INSTRUCTION.
• Register "instruction" in PARAM_ALIASES for explicit form-data parsing.

Root Cause

The lego task was generating noise because the DiT model received the wrong instruction text during inference. The model was trained with "Generate the {TRACK_NAME} track based on the audio context:" but inference was using "Fill the audio semantic mask based on the given conditions:" (the default text2music instruction).

_resolve_instruction() only substituted the task-specific instruction when req.instruction == DEFAULT_DIT_INSTRUCTION. If the instruction field arrived as an empty string from the client form data, it would not match the default and would pass through unchanged — resulting in the wrong instruction reaching the model.

Verification

Before fix: Peak=0.0045 (noise)
After fix: Peak=1.0000 (normal audio signal)

Test plan

• Existing job_generation_setup_test.py tests pass (4/4)
• Server restart and manual lego task request confirms correct instruction in logs
• DAW client lego generation (from silence + from context) produces audible music instead of noise

Made with Cursor

Summary by CodeRabbit

• New Features

  • Instruction parameter is now supported in API requests.

• Bug Fixes

  • Improved instruction resolution to handle missing or empty instruction values by falling back to task-specific defaults.

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

📝 Walkthrough

Walkthrough

Added an "instruction" parameter alias to the request parameter parser, enabling direct retrieval of instruction values from requests. Updated instruction resolution logic to handle missing or blank instructions alongside exact default instruction matches, broadening fallback behavior when task types are present.

Changes

Cohort / File(s)	Summary
Parameter Alias Mapping acestep/api/http/release_task_param_parser.py	Added "instruction": ["instruction"] entry to PARAM_ALIASES to enable canonical request parameter alias lookup for instruction values.
Instruction Resolution Logic acestep/api/job_generation_setup.py	Modified _resolve_instruction to replace instructions when missing, blank (after stripping), or exactly matching default_dit_instruction, requiring req.task_type to exist in task_instructions. Previously only replaced on exact default match.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 A whispered instruction, now properly named,
Parameter alias—no longer unnamed,
When blanks and defaults align just right,
The task instructions shine ever so bright!

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately reflects the main changes: fixing instruction mismatch in lego task that was causing noise output, which is the core issue addressed across both modified files.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

_{✏️ 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 fix/lego-instruction-mismatch

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

Tip

You can enable review details to help with troubleshooting, context usage and more.

Enable the reviews.review_details setting to include review details such as the model used, the time taken for each step and more in the review comments.