Deduplicate changelog entries from generated types module

[msyyc]

Problem

When running azpysdk breaking . --changelog --use-apistub, newly added models can appear twice in the changelog, e.g.:

### Features Added
  - Client `ComputeLimitMgmtClient` added operation group `trusted_host_subscriptions`
  - Added model `TrustedHostSubscription`
  - Added model `TrustedHostSubscriptionsOperations`
  - Added model `TrustedHostSubscription`   <-- duplicate

Root cause

TypeSpec generated libraries emit a types module (e.g. azure.mgmt.computelimit.types) containing TypedDict input aliases that shadow the real models defined in the sibling models module (azure.mgmt.computelimit.models). A newly added model is therefore defined in both modules, so the changelog checker reports an AddedClass feature for each. Because the Added model \{}`` message only uses the class name (not the module), the two entries render identically and show up as a visible duplicate.

Fix

Add a ShadowTypesModuleChecker post-processing step (registered in POST_PROCESSING_CHECKERS).

A types-module entry is dropped only when the sibling models module reports the same change — i.e. the same change type and arguments, with the module substituted. This targeted match avoids silently dropping a change that exists only on the types side (which would otherwise disappear from the breaking-change / changelog output).

When building the match key, class names and semantic values (type strings, defaults) are compared exactly; only the member-name position is normalized to snake_case, because the types TypedDicts expose wire names (e.g. serviceTreeId) while the models classes expose the Python attribute names (e.g. service_tree_id). This lets a genuine member-level duplicate match across the two naming styles while preserving unmatched, types-only changes and avoiding false collisions on class names.

The sibling models match keys are indexed once so each types entry is checked with an O(1) lookup (no per-entry rescans).

Tests

Added tests in tests/test_changelog.py:

• test_shadow_types_module_cleanup — a model added to both models and types is reported once (from models).
• test_shadow_types_module_kept_without_models_sibling — a standalone types module (no sibling models) is not stripped.
• test_shadow_types_module_kept_when_class_missing_in_models — a types class with no models counterpart is preserved.
• test_shadow_types_module_breaking_change_preserved_for_unmatched_member — an unmatched types breaking change is preserved while a mirrored addition is deduped.
• test_shadow_types_module_member_change_preserved_when_not_mirrored — an unmatched member change on a class present in both modules is preserved.
• test_shadow_types_module_member_change_deduped_across_naming — a member change reported in both modules is deduped despite the serviceTreeId vs service_tree_id naming difference.
• test_shadow_types_module_class_name_matched_exactly — class names are matched exactly (no snake_case normalization), so differently-named classes that would collide under normalization are not deduped.

And a scalability test in tests/test_performance.py:

• TestShadowTypesModuleCheckerPerformance::test_shadow_types_cleanup_performance_large — 10,000 entries are processed in well under a second (verifies the O(n) set-based lookup).

Relevant suites (test_changelog.py, test_apiview_converter.py, shadow-types perf test) pass locally: 34 passed, 1 skipped.

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[azure-pipelines]

Azure Pipelines:
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[Copilot]

Pull request overview

Adds post-processing to deduplicate changelog entries emitted by generated types modules.

Changes:

• Adds and registers ShadowTypesModuleChecker.
• Adds tests for shadowed and standalone types modules.
• However, filtering is overly broad and linked issue #48107 remains unresolved.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
scripts/breaking_changes_checker/checkers/shadow_types_module_checker.py	Filters reports from shadow types modules.
scripts/breaking_changes_checker/supported_checkers.py	Registers the new checker.
scripts/breaking_changes_checker/tests/test_changelog.py	Tests types-module cleanup behavior.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated no new comments.