Add Span/Memory overloads to Assert.HasCount and extend MSTEST0037

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.

[Amaury Levé (Evangelink)]

Fixes#9143.

What

Adds Span<T>/ReadOnlySpan<T>/Memory<T>/ReadOnlyMemory<T> overloads to Assert.HasCount and extends analyzer MSTEST0037 to flag Assert.AreEqual(x, span/memory.Length) and offer a code fix to Assert.HasCount(x, span).

Changes

• Assert.Count.cs — 4 span/memory HasCount overloads, each with a plain string? message and an interpolated-string-handler variant, plus 4 handler constructors and a span-based private impl. Guarded #if NETCOREAPP3_1_OR_GREATER (System.Memory isn't referenced for netstandard2.0/net462).
• PublicAPI/net/PublicAPI.Unshipped.txt — declared the 12 new net-only public APIs.
• UseProperAssertMethodsAnalyzer.Collection.cs — added IsSpanOrMemoryType plus a dedicated branch so span/memory .Length always maps to HasCount (never IsEmpty/IsNotEmpty, which have no span overloads). The IsTrue/IsFalse empty/not-empty path is intentionally left untouched for span/memory.
• Tests — 9 framework tests (AssertTests.Items.cs) + 7 analyzer tests (UseProperAssertMethodsAnalyzerTests.cs, guarded #if NET8_0_OR_GREATER).

Behavioral note / trade-off

Span/ReadOnlySpan are ref structs, so they need explicit overloads. A side effect is that arrays now bind to the ReadOnlySpan<T> overload during overload resolution (previously IEnumerable<T>). The interpolated-handler variants preserve lazy failure-message evaluation, but Assert.HasCount(<array>, …, $"…{await …}…") becomes a compile error (CS4007 — a span can't be preserved across await). This is inherent to ref-struct overloads; one existing test that used that pattern was switched to a List<int>.

Verification

• TestFramework + analyzers build clean (0 warnings/errors) across all TFMs.
• Framework AssertTests: 967 pass (net8.0); net48 span tests correctly guarded out.
• UseProperAssertMethodsAnalyzerTests: 125 pass (net8.0), 118 (net472, span tests excluded by the guard).
• Microsoft.Testing.Platform.UnitTests (heavy HasCount consumer) builds clean — no rebind breakage.

[Copilot]

Pull request overview

This PR extends MSTest’s Assert.HasCount to support modern Span<T>/Memory<T> shapes (plus lazy interpolated-string failure messages) and updates analyzer MSTEST0037 so Assert.AreEqual(expected, spanOrMemory.Length) can be rewritten to Assert.HasCount(expected, spanOrMemory).

Changes:

• Added HasCount overloads for Span<T>, ReadOnlySpan<T>, Memory<T>, and ReadOnlyMemory<T> (guarded to NETCOREAPP3_1_OR_GREATER), including interpolated-string-handler variants.
• Updated MSTEST0037 recognition to treat span/memory .Length as a HasCount candidate (never IsEmpty/IsNotEmpty).
• Added/updated unit tests covering the new overload behavior and the analyzer/code-fix behavior (with TFM guards where needed).

Show a summary per file

File	Description
test/UnitTests/TestFramework.UnitTests/Assertions/AssertTests.Items.cs	Adds unit coverage for new HasCount overloads and lazy-message behavior (including array overload-resolution note).
test/UnitTests/MSTest.Analyzers.UnitTests/UseProperAssertMethodsAnalyzerTests.cs	Adds analyzer/code-fix tests for span/memory .Length → HasCount transformations (guarded to net8+).
src/TestFramework/TestFramework/PublicAPI/net/PublicAPI.Unshipped.txt	Declares the newly added net-only public APIs (overloads + handler ctors).
src/TestFramework/TestFramework/Assertions/Assert.Count.cs	Implements the span/memory HasCount overload set and handler constructors, with a span-based private implementation.
src/Analyzers/MSTest.Analyzers/UseProperAssertMethodsAnalyzer.Collection.cs	Extends count-pattern recognition to handle span/memory .Length and route it to HasCount.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Note

🤖 Automated review by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review workflow. To request a follow-up action, reply by tagging @copilot directly.

#	Dimension	Verdict
4	Public API & Binary Compatibility	🟡 1 MODERATE
13	Test Completeness & Coverage	🟡 1 MODERATE
17	Documentation Accuracy	⚪ 1 NIT
18	Analyzer & Code Fix Quality	⚪ 1 NIT

✅ 18/22 dimensions clean.

• Public API — source-breaking change for arrays with async messages: Adding ReadOnlySpan<T> overloads causes int[] (and other array types) to rebind from IEnumerable<T> to ReadOnlySpan<T> during overload resolution. Any existing call site of the form Assert.HasCount(n, someArray, $"{await task}") will fail to compile with CS4007 ("a ref struct cannot be preserved across an await point"). The PR description and a test change already document this trade-off, but it is a source-breaking change for callers mixing arrays and async interpolated messages. This should be captured in the changelog/release notes so upgrading users know to switch arrays to List<T> (or a local IEnumerable<T> variable) if they hit CS4007.
• Test Coverage — missing Span<T> / ReadOnlyMemory<T> failure-path tests: see inline comment on AssertTests.Items.cs line 202.
• NIT — private span method comment mentions "IsEmpty" which is unreachable in the span code path: see inline comment on Assert.Count.cs line 664.
• NIT — no analyzer test for non-int expected value against span .Length: see inline comment on UseProperAssertMethodsAnalyzerTests.cs.

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Expert Code Review (on PR ready) workflow. · 707.8 AIC · ⌖ 12.9 AIC · ◷

[Copilot]

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 1

[Amaury Levé (Evangelink)]

🧪 Test quality grade — PR #9176

21 tests graded across 2 files. 17 A, 4 B — a strong contribution overall. The four B-grade tests are minimal happy-path smoke tests with a single assertion each; they are adequately paired with dedicated ShouldFail counterparts, so no action is required. The 10 AssertTests failure-path tests are notably thorough, using exact-message matching and side-effect checks. Analyzer tests follow the established VerifyCodeFixAsync/VerifyAnalyzerAsync pattern cleanly throughout.

Δ	Test	Grade	Band	Notes
new	AssertTests. Count_ Memory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Span_ WhenCountIsSame_ ShouldPass	B	80–89	Single pass-path assertion; companion ShouldFail test covers the failure path.
new	AssertTests. Count_ Array_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	Comment explains overload-binding change; no-throw + lazy-eval assertions cover the new behavior.
mod	AssertTests. Count_ InterpolatedString_ WhenCountIsNotSame_ ShouldFail	A	90–100	Exception + message + side-effect checks; DateTime.Now captured once — consistent use, not a timing risk.
new	AssertTests. Count_ Memory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, exact message, WasToStringCalled); full failure-path coverage.
new	AssertTests. Count_ Memory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message assertion; clean and complete.
new	AssertTests. Count_ ReadOnlyMemory_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions (exception, message, side-effect); idiomatic lambda pattern.
new	AssertTests. Count_ ReadOnlyMemory_ WhenCountIsNotSame_ ShouldFail	A	90–100	Lambda + exact message; clean and complete.
new	AssertTests. Count_ ReadOnlySpan_ InterpolatedString_ WhenCountIsSame_ ShouldNotEvaluateMessage	A	90–100	No-throw + WasToStringCalled.BeFalse() together verify lazy-eval semantics.
new	AssertTests. Count_ ReadOnlySpan_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified by span constraints; null check + exact message cover the contract.
new	AssertTests. Count_ Span_ InterpolatedString_ WhenCountIsNotSame_ ShouldEvaluateMessageAndFail	A	90–100	Three assertions; try/catch justified by span constraints; clear rationale in comment.
new	AssertTests. Count_ Span_ WhenCountIsNotSame_ ShouldFail	A	90–100	try/catch justified; null check + exact message verify the failure contract.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlyMemoryLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithReadOnlySpanLengthNonZero	A	90–100	No issues found.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonIntExpected_ NoDiagnostic	A	90–100	Negative boundary test; comment explains why long/int? must not trigger the rule.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthNonZero	A	90–100	Verifies diagnostic location and code-fix rewrite; clear AAA.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertAreEqualWithSpanLengthZero_ SuggestsHasCountNotIsEmpty	A	90–100	Comment pins the 'HasCount(0) not IsEmpty' edge case; verifies diagnostic + fix output.
new	UseProperAssertMethodsAnalyzerTests. WhenAssertIsTrueWithSpanLengthGreaterThanZero_ UsesIsGreaterThanNotIsNotEmpty	A	90–100	Comment clarifies 'IsGreaterThan vs IsNotEmpty' distinction; verifies fix correctly.

_{This advisory comment was generated automatically. Grades are heuristic
and informational — they do not block merging. Re-run with
/grade-tests.}

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Grade Tests on PR (on open / sync) workflow. · 404.6 AIC · ⌖ 14.1 AIC · [◷]( · ◷)

[avivanoff]

Amaury Levé (@Evangelink), YuliiaKovalova, this is still broken when targeting .NET Framework 4.8, etc. MSTEST0037 is triggered, but Assert.HasCount overload does not exist.