chore(low-code): remove unused SubstreamPartitionRouter._migrate_child_state_to_parent_state

[Serhii Lazebnyi (lazebnyi)]

What

Remove SubstreamPartitionRouter._migrate_child_state_to_parent_state — it has no callers anywhere in the codebase.

Why

It's dead code left over from the pre-concurrent implementation: parent state is now seeded at stream-construction time in ModelToComponentFactory._instantiate_parent_stream_state_manager. Leaving it around is misleading — the analysis in #1067 anchored on it as a suspected root cause, and #1079 independently noted it has no callers.

Test

• grep -rn _migrate_child_state_to_parent_state — no remaining references (production or tests)
• pytest unit_tests/sources/declarative/partition_routers/ — 68 passed

Summary by CodeRabbit

• Refactor
  • Simplified internal state handling by removing legacy parent-state migration logic.
  • Existing parent-state retrieval behavior remains unchanged.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 0cc4bd4d-2bb0-4ee6-9425-4739f7c2a0c0

📥 Commits

Reviewing files that changed from the base of the PR and between 62b3165 and 991de2a.

📒 Files selected for processing (1)

• airbyte_cdk/sources/declarative/partition_routers/substream_partition_router.py

💤 Files with no reviewable changes (1)

• airbyte_cdk/sources/declarative/partition_routers/substream_partition_router.py

---

📝 Walkthrough

Walkthrough

The substream partition router removes _migrate_child_state_to_parent_state. Parent state retrieval through get_stream_state remains unchanged.

Changes

State handling

Layer / File(s)	Summary
Remove child-state migration airbyte_cdk/sources/declarative/partition_routers/substream_partition_router.py	Removes state-format conversion, validation, and incremental parent-state migration for child or global stream state.

Estimated code review effort: 2 (Simple) | ~5 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the removal of the unused method, which is the main change in the pull request.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ 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 lazebnyi/remove-dead-migrate-child-state

---

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.}

[github-actions]

👋 Greetings, Airbyte Team Member!

Here are some helpful tips and reminders for your convenience.

💡 Show Tips and Tricks

Testing This CDK Version

You can test this version of the CDK using the following:

# Run the CLI from this branch:
uvx 'git+https://github.com/airbytehq/airbyte-python-cdk.git@lazebnyi/remove-dead-migrate-child-state#egg=airbyte-python-cdk[dev]' --help

# Update a connector to use the CDK from this branch ref:
cd airbyte-integrations/connectors/source-example
poe use-cdk-branch lazebnyi/remove-dead-migrate-child-state

PR Slash Commands

Airbyte Maintainers can execute the following slash commands on your PR:

• /autofix - Fixes most formatting and linting issues
• /poetry-lock - Updates poetry.lock file
• /test - Runs connector tests with the updated CDK
• /prerelease - Triggers a prerelease publish with default arguments
• /poe build - Regenerate git-committed build artifacts, such as the pydantic models which are generated from the manifest JSON schema in YAML.
• /poe <command> - Runs any poe command in the CDK environment

📚 Show Repo Guidance

Helpful Resources

• CDK API Reference

📝 Edit this welcome message.

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 1 additional finding.

[github-actions]

PyTest Results (Fast)

4 183 tests  ±0   4 171 ✅ ±0   6m 7s ⏱️ - 1m 43s
    1 suites ±0      12 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit 991de2a. ± Comparison against base commit 62b3165.

♻️ This comment has been updated with latest results.

[github-actions]

PyTest Results (Full)

4 184 tests  ±0   4 172 ✅ ±0   12m 33s ⏱️ +28s
    1 suites ±0      12 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit 408e6fb. ± Comparison against base commit 4758b15.

♻️ This comment has been updated with latest results.