[7.0] Address flaky DEBUG assertions

[paulmedynski]

Description

Port of #4085 to release/7.0.

Refactors the DataTestUtility.AssertThrowsWrapper assertion helpers and fixes race condition test failures across the manual test suite.

Problem

1. Flaky assertion regression: A DEBUG assertion started failing on Ubuntu .NET 8 in PR pipelines, causing test failures in DataStreamTest (see SqlDataReader async read throws inconsistent exception types on disposal (IOException vs InvalidOperationException) #4088, Fix commented-out Debug.Assert()s that are failing #3604).
2. Race conditions in async disposal: When PendAsyncReadsScope is disposed while an async ReadAsync is in-flight, the inner exception type varies depending on timing — it may be IOException, InvalidOperationException, ObjectDisposedException, or TaskCanceledException. The existing assertion helpers only accepted a single expected type and would fail intermittently.
3. Misleading assertion helpers: AssertThrowsWrapper accepted generic type parameters for inner/inner-inner exceptions but never validated them with actual type checks. It also had unused parameters (innerExceptionMustBeNull, customExceptionVerifier, innerInnerInnerExceptionMustBeNull) that no callers were passing.
4. Duplicated exception-handling code: Six identical try { t.Wait(); } catch (AggregateException) { ... } blocks were scattered throughout DataStreamTest.cs.

Changes

DataTestUtility.cs — Assertion helper redesign

Replaced the three AssertThrowsWrapper overloads with four properly-typed, well-documented helpers:

Old Method	New Method	What Changed
AssertThrowsWrapper<T>(...)	AssertThrows<T>(...)	Removed unused params (innerExceptionMustBeNull, customExceptionVerifier)
AssertThrowsWrapper<T, TInner>(...)	AssertThrowsInner<T, TInner>(...)	Now actually validates the inner exception type via Assert.IsAssignableFrom<TInnerException>
AssertThrowsWrapper<T, TInner, TInnerInner>(...)	AssertThrowsInnerWithAlternate<T, TInner, TAlt>(...)	Repurposed: accepts two possible inner exception types for race conditions instead of checking inner-inner exceptions

All helpers are wrapped in a #nullable enable block with XML documentation.

DataStreamTest.cs — Race condition fixes

• Extracted WaitIgnoringFlakyException(Task): Replaces 6 duplicated try/catch blocks. Calls task.Wait() and ignores AggregateException only for faulted tasks (with a comment explaining that a faulted Task permanently stores its exception, so re-waiting always rethrows).
• Fixed race-prone assertion sites using AssertThrowsInnerWithAlternate:
  • Lines ~1407, ~1797, ~1813: IOException ↔ InvalidOperationException depending on reader disposal timing
  • Line ~1828: TaskCanceledException ↔ InvalidOperationException depending on PendAsyncReadsScope disposal timing
  • Lines ~1841, ~1969: Inline assertions handling IOException → SqlException or ObjectDisposedException alternate path
• Removed all TODO(GH-3604) comments — replaced with proper alternate-type assertions that handle the race correctly.
• Added explanatory comments at each race-prone site referencing SqlDataReader async read throws inconsistent exception types on disposal (IOException vs InvalidOperationException) #4088.

22 other test files — Assertion renames

All call sites across the manual test suite updated from AssertThrowsWrapper to the new names:

• AssertThrowsWrapper<T>(...) → AssertThrows<T>(...)
• AssertThrowsWrapper<T, TInner>(...) → AssertThrowsInner<T, TInner>(...)

Files: AdapterTest, LocalDBTest, MARSTest, ParallelTransactionsTest, ParametersTest, 10 SqlBulkCopy tests, SqlCommandCancelTest, SqlNotificationTest, TransactionTest, UdtTest2, CopyAllFromReaderConnectionCloseOnEventAsync.

Minor cleanups

• Fixed #pragma warning indentation in DataTestUtility.cs
• Changed #nullable disable → #nullable restore for proper nullable context scoping

Testing

• Verified all assertion call sites compile and pass locally
• CI pipeline validates across all configurations (Windows/Linux/macOS, net462/net8.0/net9.0, ManagedSNI/NativeSNI, SQL Server 2019/2022/Azure SQL/Named Instance/ARM64)
• Confirmed the only remaining CI failure (ReadStream_ReadsStreamDataCorrectly line 1828) is fixed by the AssertThrowsInnerWithAlternate change

[Copilot]

Pull request overview

Ports PR #4085 to the release/7.0 branch by refactoring the ManualTests assertion helpers to correctly validate inner exception types and updating race-prone async-disposal tests to accept known alternate exception types, reducing DEBUG-mode flakiness on Linux/.NET.

Changes:

• Replaced DataTestUtility.AssertThrowsWrapper* overloads with new AssertThrows* helpers that properly validate inner exception types and support “alternate inner exception” races.
• Refactored DataStreamTest to remove duplicated Task.Wait()/AggregateException handling and updated race-sensitive assertions to tolerate expected alternate exception types.
• Renamed assertion helper call sites across the manual test suite to the new APIs (plus minor whitespace/format cleanups).

Reviewed changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/Microsoft.Data.SqlClient/tests/ManualTests/DataCommon/DataTestUtility.cs	Introduces new AssertThrows* helpers (with proper inner-type validation) and updates nullable scoping.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/DataStreamTest/DataStreamTest.cs	Consolidates flaky Task.Wait() handling and updates assertions for known race-condition exception variability.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/UdtTest/UdtTest2.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/TransactionTest/TransactionTest.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlNotificationTest/SqlNotificationTest.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlCommand/SqlCommandCancelTest.cs	Renames assertion helper usages to AssertThrows; minor comment whitespace cleanup.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/TransactionTestAsync.cs	Switches to AssertThrowsInner for validating AggregateException inner type.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/Transaction4.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/Transaction3.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/Transaction1.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/Transaction.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/OrderHintMissingTargetColumn.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/OrderHintDuplicateColumn.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/MissingTargetColumns.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/MissingTargetColumn.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/CopyWithEvent1.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/CopyAllFromReaderConnectionCloseOnEventAsync.cs	Adds System.IO and uses AssertThrowsInnerWithAlternate to handle race-dependent inner exception types.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/CopyAllFromReaderConnectionCloseAsync.cs	Switches to AssertThrowsInner for validating AggregateException inner type.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/SqlBulkCopyTest/CopyAllFromReaderCancelAsync.cs	Switches to AssertThrowsInner for validating AggregateException inner type.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/ParameterTest/ParametersTest.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/ParallelTransactionsTest/ParallelTransactionsTest.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/MARSTest/MARSTest.cs	Renames assertion helper usages to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/LocalDBTest/LocalDBTest.cs	Renames assertion helper usage to AssertThrows.
src/Microsoft.Data.SqlClient/tests/ManualTests/SQL/AdapterTest/AdapterTest.cs	Renames assertion helper usages to AssertThrows.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.58%. Comparing base (864f666) to head (b793595).
⚠️ Report is 2 commits behind head on release/7.0.

❗ There is a different number of reports uploaded between BASE (864f666) and HEAD (b793595). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (864f666)	HEAD (b793595)
CI-SqlClient	1	0

Additional details and impacted files

@@               Coverage Diff               @@
##           release/7.0    #4143      +/-   ##
===============================================
- Coverage        73.07%   65.58%   -7.50%     
===============================================
  Files              280      275       -5     
  Lines            42997    65822   +22825     
===============================================
+ Hits             31422    43171   +11749     
- Misses           11575    22651   +11076     

Flag	Coverage Δ
CI-SqlClient	?
PR-SqlClient-Project	65.58% <ø> (?)

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