feat(evaluator): add metric type name alias

[SandyChapman]

Summary

• add a shared non-empty MetricTypeName alias for evaluator SDK metric identifiers
• use it in Metric, MetricDescriptor, and inline metric values
• cover empty descriptor type validation in the metric contract tests

Testing

• uv run --frozen ruff check packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/metrics/protocol.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/metrics.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/init.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/init.py packages/nemo_evaluator_sdk/tests/metrics/test_metric_contract.py
• uv run --frozen ruff format --check packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/metrics/protocol.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/metrics.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/init.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/init.py packages/nemo_evaluator_sdk/tests/metrics/test_metric_contract.py
• uv run --frozen --extra cpu ty check packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/metrics/protocol.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/metrics.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/init.py packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/init.py packages/nemo_evaluator_sdk/tests/metrics/test_metric_contract.py
• uv run --frozen pytest packages/nemo_evaluator_sdk/tests/metrics/test_metric_contract.py -q

Summary by CodeRabbit

• New Features

  • MetricTypeName is now available in the public API, providing a unified type definition for all metric type identifiers.

• Bug Fixes

  • Metric descriptors and metrics now consistently validate and enforce non-empty type identifiers across the entire SDK with standardized constraints.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between c87f685 and cb80057.

📒 Files selected for processing (5)

• packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/__init__.py
• packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/metrics/protocol.py
• packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/__init__.py
• packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/metrics.py
• packages/nemo_evaluator_sdk/tests/metrics/test_metric_contract.py

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📝 Walkthrough

Walkthrough

The PR introduces MetricTypeName, a non-empty string constraint, and applies it throughout the metrics SDK. The type replaces plain str in metric type fields across protocol and value layers, with automatic validation via Pydantic's annotation constraints. The type is exported as public API.

Changes

MetricTypeName constraint and propagation

Layer / File(s)	Summary
MetricTypeName type definition and protocol contract packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/metrics/protocol.py, packages/nemo_evaluator_sdk/tests/metrics/test_metric_contract.py	MetricTypeName is introduced as Annotated[str, StringConstraints(min_length=1)]. MetricDescriptor.type and Metric.type are updated to use it, eliminating the previous manual field validator. A new test verifies empty metric types are rejected.
Values layer metric type field alignment packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/metrics.py	MetricBase.type field is changed from str to MetricTypeName, applying the shared constraint consistently.
Public API exports packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/__init__.py, packages/nemo_evaluator_sdk/src/nemo_evaluator_sdk/values/__init__.py	MetricTypeName is imported and added to __all__ in both root and values package initializers, exposing it as public API.

🚥 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	Title directly describes the main change: introducing a shared MetricTypeName alias used across metric protocol, descriptor, and inline values.
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.

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✨ 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 metric-type-name/schapman

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[github-actions]

Documentation preview is ready

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[github-actions]

Suite	Lines Covered	Line Rate	Branch Rate
Unit Tests	18244/24191	75.4%	61.9%
Integration Tests	11667/22973	50.8%	25.9%