Add MSTEST0070 analyzer validating [Condition] member references

[Evangelink]

Follow-up to #9071 (per design review).

Summary

Adds MSTEST0070 — ConditionShouldBeValidAnalyzer, which catches at build time the same errors that ConditionAttribute.IsConditionMet throws at runtime, so typos and refactors don't silently break test gating.

This is the analyzer counterpart called out as a follow-up in #9071 and addresses the user feedback "add an analyzer to detect if the member targets (or type detected) is invalid".

⚠️ Stacked on top of #9071. This branch is cut from evangelink/issue-9070-condition-attribute, so the diff currently includes commits from that PR. Once #9071 merges, GitHub will rebase the diff to only show the analyzer-specific changes.

Diagnostics

One diagnostic is produced per invalid member name on each [Condition] attribute.

Rule	Condition
MemberNotFoundRule	The named member doesn't exist on the type.
MemberNotPublicRule	Member is not public.
MemberNotStaticRule	Member is not static.
MemberWrongKindRule	Member is an event, nested type, or other unsupported kind.
MemberWrongReturnTypeRule	Property / field / method doesn't return bool.
MethodHasParametersRule	Referenced method has parameters.
PropertyNotReadableRule	Property has no public getter (write-only).

All seven diagnostics share id MSTEST0070 with different message formats, matching how MSTEST0018 (DynamicData) is structured.

Example

public static class Conditions
{
    public static bool IsTrue => true;
    public static int NotBool => 0;
    public static bool WithParam(int x) => x > 0;
    internal static bool InternalIsTrue => true;
}

[TestClass]
public class MyTests
{
    [Condition(typeof(Conditions), "Mispelled")]                  // MSTEST0070: cannot be found
    [Condition(typeof(Conditions), nameof(Conditions.NotBool))]   // MSTEST0070: must return 'bool'
    [Condition(typeof(Conditions), nameof(Conditions.WithParam))] // MSTEST0070: must be parameterless
    [Condition(typeof(Conditions),
               nameof(Conditions.InternalIsTrue))]                // MSTEST0070: must be 'public'
    [TestMethod]
    public void MyTest() { }
}

Coverage

• Fires on both test methods and test classes (the attribute is AttributeUsage(Class | Method)).
• Validates every member name passed to the attribute — the simple (Type, string) ctor, the params string[] overload, and the ConditionMode-prefixed overloads.
• Stacked [Condition] attributes are each validated independently.
• Inherited public static members are recognized (walks BaseType chain), matching BindingFlags.Public | Static | FlattenHierarchy.
• The resolution order matches the runtime (property → field → method), so if a property and method share a name only the property is validated — consistent with what would actually be invoked.

Tests

18 tests in test/UnitTests/MSTest.Analyzers.UnitTests/ConditionShouldBeValidAnalyzerTests.cs:

• Valid: public static bool property / field / parameterless method, inherited public static member
• Invalid: missing, non-public (internal), instance property, instance field, non-bool property, non-bool field, non-bool method, method with parameters, write-only property, event
• Composition: multiple invalid member names in one attribute (each reported), multiple [Condition] attributes on one method (each validated), ConditionMode.Exclude ctor overload, attribute on class target

All 18 pass on net8.0.

Files touched

• ➕ src/Analyzers/MSTest.Analyzers/ConditionShouldBeValidAnalyzer.cs
• ➕ test/UnitTests/MSTest.Analyzers.UnitTests/ConditionShouldBeValidAnalyzerTests.cs
• ✏️ src/Analyzers/MSTest.Analyzers/Helpers/DiagnosticIds.cs (added ConditionShouldBeValidRuleId = "MSTEST0070")
• ✏️ src/Analyzers/MSTest.Analyzers/Helpers/WellKnownTypeNames.cs (added ConditionAttribute entry)
• ✏️ src/Analyzers/MSTest.Analyzers/Resources.resx + 13 .xlf files (regenerated via dotnet msbuild /t:UpdateXlf)
• ✏️ src/Analyzers/MSTest.Analyzers/AnalyzerReleases.Unshipped.md

Notes for reviewers

• Severity is Warning, enabled by default — matches MSTEST0018 (DynamicData) which solves the same class of problem. Happy to downgrade to Info if you'd prefer a softer rollout.
• Documentation URL https://learn.microsoft.com/dotnet/core/testing/mstest-analyzers/mstest0070 will be authored as a separate dotnet/docs PR after this merges.
• No code fix provider — the right fix depends on user intent (rename member? change accessibility? change member kind?). Keeping it diagnostic-only matches DynamicDataShouldBeValidAnalyzer.

[Evangelink]

🧪 Test quality grade — PR #9076

Δ	Test	Grade	Band	Notes
new	ConditionShouldBeValidAnalyzerTests. WhenAdditionalMembersAreInvalid_ AllReported	A	90–100	Verifies two independent diagnostics (MemberNotFound + MemberWrongReturnType) for a single multi-member attribute call.
new	ConditionShouldBeValidAnalyzerTests. WhenAttributeIsOnTestClass_ StillValidated	A	90–100	Confirms class-level [Condition] triggers the same validation; checks exact rule, location, and type+member arguments.
new	ConditionShouldBeValidAnalyzerTests. WhenExplicitConditionMode_ StillValidated	A	90–100	Verifies that passing an explicit ConditionMode does not bypass member validation.
new	ConditionShouldBeValidAnalyzerTests. WhenFieldIsNonBool_ MemberWrongReturnType	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenInheritedPublicStaticMember_ NoDiagnostic	A	90–100	No issues found; covers the inherited-member edge case to prevent false positives.
new	ConditionShouldBeValidAnalyzerTests. WhenMemberDoesNotExist_ MemberNotFound	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMemberIsEvent_ MemberWrongKind	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMemberIsInternal_ MemberNotPublic	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMemberIsValidPublicStaticBoolField_ NoDiagnostic	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMemberIsValidPublicStaticBoolMethod_ NoDiagnostic	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMemberIsValidPublicStaticBoolProperty_ NoDiagnostic	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMethodHasParameters_ MethodHasParameters	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMethodReturnsNonBool_ MemberWrongReturnType	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenMultipleConditionAttributes_ EachValidated	A	90–100	Verifies each of two stacked [Condition] attributes is flagged at its own distinct location.
new	ConditionShouldBeValidAnalyzerTests. WhenPropertyIsInstance_ MemberNotStatic	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenPropertyIsWriteOnly_ PropertyNotReadable	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenPropertyReturnsNonBool_ MemberWrongReturnType	A	90–100	No issues found.
new	ConditionShouldBeValidAnalyzerTests. WhenStaticFieldIsInstance_ MemberNotStatic	A	90–100	No issues found.

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

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