feat: Replace MyPy with ty type checker (do not merge)

[aaronsteers]

Replace MyPy with ty type checker (do not merge)

Summary

This PR replaces MyPy with ty (the new Rust-based Python type checker from astral-sh) across both PyAirbyte and airbyte-python-cdk repositories for performance and usability testing. This is an experimental change to evaluate ty as an alternative to MyPy.

Key changes:

• Replace mypy dependency with ty ^0.0.1a16 in pyproject.toml
• Remove MyPy configuration sections and add [tool.ty.src] configuration
• Update CI workflows from mypy-check to ty-check
• Create/update generic type-check Poe tasks using ty commands
• Configure appropriate file exclusions for ty checking

⚠️ Important Notes:

• ty is significantly stricter than MyPy (found 108 errors in PyAirbyte, 205 in airbyte-python-cdk)
• This is marked "do not merge" as it's for testing/evaluation only
• ty lacks CLI auto-noqa features (unlike pyrefly), requiring manual error suppression

Review & Testing Checklist for Human

• Run type checking locally: Execute poetry run poe type-check in both repos to verify ty works correctly
• Test CI workflow changes: Verify that the updated GitHub Actions workflows execute ty-check properly
• Verify exclusion patterns: Confirm that [tool.ty.src] exclude settings properly skip tests/docs/fixtures directories
• Test poethepoet integration: Run poetry run poe check to ensure ty integrates correctly with existing task chains
• Check development workflow: Ensure the stricter type checking doesn't break normal development processes

Recommended test plan: Install dependencies in both repos, run type-check tasks locally, verify output shows expected ty diagnostics, then check that CI workflows complete (failures expected due to existing type violations).

---

Diagram

%%{ init : { "theme" : "default" }}%%
graph TD
    PyAirbyte_pyproject["PyAirbyte/<br/>pyproject.toml"]:::major-edit
    PyAirbyte_workflow["PyAirbyte/<br/>.github/workflows/<br/>python_lint.yml"]:::major-edit
    PyAirbyte_lock["PyAirbyte/<br/>poetry.lock"]:::minor-edit
    
    CDK_pyproject["airbyte-python-cdk/<br/>pyproject.toml"]:::major-edit
    CDK_workflow["airbyte-python-cdk/<br/>.github/workflows/<br/>python_lint.yml"]:::major-edit
    CDK_mypy_ini["airbyte-python-cdk/<br/>mypy.ini"]:::major-edit
    
    
    ty_config["[tool.ty.src]<br/>configuration"]:::context
    poe_tasks["poethepoet<br/>type-check tasks"]:::context
    
    PyAirbyte_pyproject --> ty_config
    CDK_pyproject --> ty_config
    PyAirbyte_pyproject --> poe_tasks
    CDK_pyproject --> poe_tasks
    
    PyAirbyte_workflow --> |"replaces mypy-check<br/>with ty-check"| PyAirbyte_pyproject
    CDK_workflow --> |"replaces mypy-check<br/>with ty-check"| CDK_pyproject
    CDK_mypy_ini --> |"deleted"| CDK_pyproject
    
    subgraph Legend
        L1["Major Edit"]:::major-edit
        L2["Minor Edit"]:::minor-edit
        L3["Context/No Edit"]:::context
    end

classDef major-edit fill:#90EE90
classDef minor-edit fill:#87CEEB
classDef context fill:#FFFFFF

Loading

Notes

• This work was requested by @aaronsteers as part of evaluating new Rust-based Python type checkers
• Session URL: https://app.devin.ai/sessions/89f33f9cbd9f48bda7165514bc3c1005
• ty version 0.0.1a16 is very experimental - expect potential issues
• A follow-up PR will test pyrefly (Meta's Rust-based type checker) for comparison
• The stricter type checking may reveal legitimate type issues that were missed by MyPy

[devin-ai-integration]

Original prompt from AJ Steers:

@Devin - I'm wanting to put the two new rust Python typing libraries to the test. Create one PR to use ty and one PR to use pyre-something from meta.

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring

[github-actions]

👋 Greetings, Airbyte Team Member!

Here are some helpful tips and reminders for your convenience.

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@devin/1738195530-test-ty-type-checker#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 devin/1738195530-test-ty-type-checker

Helpful Resources

• CDK API Reference

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
• /poe <command> - Runs any poe command in the CDK environment

📝 Edit this welcome message.

[github-actions]

PyTest Results (Fast)

3 700 tests  ±0   3 689 ✅ ±0   6m 31s ⏱️ +5s
    1 suites ±0      11 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit df07ecb. ± Comparison against base commit a59d25f.

♻️ This comment has been updated with latest results.

To fix the issue, we will add a permissions block at the root of the workflow file. This block will apply to all jobs in the workflow unless overridden by job-specific permissions blocks. Since the workflow only performs read-only operations (e.g., checking out code, installing dependencies, and running checks), we will set contents: read as the minimal required permission.

---

[github-actions]

PyTest Results (Full)

3 703 tests  ±0   3 692 ✅ ±0   18m 3s ⏱️ -48s
    1 suites ±0      11 💤 ±0 
    1 files   ±0       0 ❌ ±0 

Results for commit df07ecb. ± Comparison against base commit a59d25f.

♻️ This comment has been updated with latest results.