// Use when a user says "add a ty diagnostic", "write this new ty diagnostic", "change a ty error message", "review ty diagnostics", or asks to add, update, or review ty checks, diagnostic messages, subdiagnostics, or concise output behavior.
Use when a user says "work on ty", "fix this ty issue", "debug ty", "update this ty PR", or asks about ty type checker changes, issues, branches, failing tests, or PRs in the Ruff repository.
Use when a user says "minimize this ty ecosystem change", "reproduce this ecosystem result", "investigate a primer difference", "investigate a mypy_primer difference", "investigate a mypy-primer difference", or asks to reproduce, investigate, or minimize behavior changes in ty ecosystem/primer/mypy_primer/mypy-primer projects.
Use when a user says "summarise ecosystem results", "summarize this ty ecosystem report", "what changed in this ecosystem run?", or asks to summarise or summarize ty ecosystem results for a Ruff PR from a PR number, PR URL, GitHub ecosystem-results comment, or detailed HTML report.
| name | adding-ty-diagnostics |
| description | Use when a user says "add a ty diagnostic", "write this new ty diagnostic", "change a ty error message", "review ty diagnostics", or asks to add, update, or review ty checks, diagnostic messages, subdiagnostics, or concise output behavior. |
Use this skill when adding or changing a ty diagnostic, especially as part of a new ty check.
Keep error messages concise. Think about how the diagnostic will look on a narrow terminal screen.
Put extra detail in subdiagnostics or secondary annotations when that helps, but make sure the primary diagnostic is understandable on its own.
Always check that the diagnostic still makes sense when the user passes --output-format=concise.
If the error code is entirely new or if you have changed the documentation for the error code,
you will need to run cargo dev generate-all after making your changes, to update the generated schema for ty
and the generated .md documentation files.
Diagnostics should usually be tested using mdtests. If you are changing behaviour for an existing diagnostic,
you should usually add your tests to a pre-existing .md file; otherwise, it may be appropriate to add a new
.md file for your tests. Snapshot tests are only usually necessary for diagnostics that use secondary annotations
or subdiagnostics. If you want to add a snapshot, inline # snapshot comments are preferred over the legacy
<!-- snapshot-annotations --> directive.
When using the declare_lint! macro, the status field should be set to LintStatus::stable(<next version of ty>).
You should determine what the next version of ty will be by inspecting https://pypi.org/pypi/ty/json, finding what
the latest release of ty is, and incrementing the patch version by one. For example, if the latest release of ty is 0.5.3, the status should be LintStatus::stable("0.5.4").
