Document MSTEST0070 (MemberCondition arguments should be valid)

docs/core/testing/mstest-analyzers/mstest0070.md

@@ -0,0 +1,146 @@
+---
+title: "MSTEST0070: [MemberCondition] arguments should be valid"
+description: "Learn about code analysis rule MSTEST0070: [MemberCondition] arguments should be valid"
+ms.date: 06/19/2026
+f1_keywords:
+- MSTEST0070
+- MemberConditionShouldBeValidAnalyzer
+helpviewer_keywords:
+- MemberConditionShouldBeValidAnalyzer
+- MSTEST0070
+author: evangelink
+ms.author: amauryleve
+ai-usage: ai-assisted
+dev_langs:
+- CSharp
+---
+# MSTEST0070: \[MemberCondition] arguments should be valid
+
+| Property                            | Value                                              |
+|-------------------------------------|----------------------------------------------------|
+| **Rule ID**                         | MSTEST0070                                          |
+| **Title**                           | \[MemberCondition] arguments should be valid        |
+| **Category**                        | Usage                                              |
+| **Fix is breaking or non-breaking** | Non-breaking                                       |
+| **Enabled by default**              | Yes                                                |
+| **Default severity**                | Warning                                            |
+| **Introduced in version**           | 4.3.0                                              |
+| **Is there a code fix**             | No                                                 |
+
+## Cause
+
+A `[MemberCondition]` attribute references a member that the test framework can't evaluate. The referenced member must exist on the referenced type, be `public static`, return `bool`, and (for methods) be parameterless.
+
+## Rule description
+
+The `[MemberCondition]` attribute conditionally runs or skips a test class or test method based on the value of one or more static `bool` members. You reference each member by its declaring type and name, for example `[MemberCondition(typeof(MyConditions), nameof(MyConditions.IsEnabled))]`.
+
+Because the member is referenced by name, the test framework resolves it through reflection at run time. If the member doesn't exist, isn't `public`, isn't `static`, doesn't return `bool`, requires parameters, or is a write-only property, evaluating the condition throws an <xref:System.InvalidOperationException> and the test fails. This analyzer surfaces those problems at build time so that typos and refactors don't silently break test gating.
+
+The rule reports a violation when a referenced member:
+
+- Can't be found on the referenced type.
+- Isn't `public`.
+- Isn't `static`.
+- Isn't a property, field, or parameterless method.
+- Doesn't return `bool`.
+- Is a method that declares parameters.
+- Is a property without a getter.
+
+```csharp
+public class TestConditions
+{
+    public static bool IsEnabled => true;
+    private static bool IsHidden => true;          // not public
+    public bool IsInstance => true;                // not static
+    public static int Count => 0;                  // wrong return type
+    public static bool IsReady(string mode) => true; // has parameters
+}
+
+[TestClass]
+public class MyTestClass
+{
+    [TestMethod]
+    [MemberCondition(typeof(TestConditions), "IsEnable")] // Violation - member not found (typo)
+    public void Test1()
+    {
+    }
+
+    [TestMethod]
+    [MemberCondition(typeof(TestConditions), nameof(TestConditions.IsInstance))] // Violation - not static
+    public void Test2()
+    {
+    }
+
+    [TestMethod]
+    [MemberCondition(typeof(TestConditions), nameof(TestConditions.Count))] // Violation - doesn't return bool
+    public void Test3()
+    {
+    }
+}
+```
+
+## How to fix violations
+
+Reference a member that is `public static`, returns `bool`, and (for methods) is parameterless. Fix the member name if it's a typo, or adjust the member declaration so it meets the requirements.
+
+```csharp
+public class TestConditions
+{
+    public static bool IsEnabled => true;
+}
+
+[TestClass]
+public class MyTestClass
+{
+    [TestMethod]
+    [MemberCondition(typeof(TestConditions), nameof(TestConditions.IsEnabled))]
+    public void Test1()
+    {
+    }
+}
+```
+
+Use `nameof` instead of a string literal so the compiler and this rule keep the reference in sync when you rename the member.
+
+You can also reference a field or a parameterless method, combine several members (they're AND-combined), and use <xref:Microsoft.VisualStudio.TestTools.UnitTesting.ConditionMode> to invert the condition:
+
+```csharp
+[TestMethod]
+[MemberCondition(
+    typeof(TestConditions),
+    nameof(TestConditions.IsEnabled),
+    nameof(TestConditions.IsSupported))] // runs only when both are true
+public void Test2()
+{
+}
+
+[TestMethod]
+[MemberCondition(ConditionMode.Exclude, typeof(TestConditions), nameof(TestConditions.IsLegacy))] // skipped when true
+public void Test3()
+{
+}
+```
+
+## When to suppress warnings
+
+Don't suppress warnings from this rule. A `[MemberCondition]` attribute that references an invalid member throws at run time and causes the test to fail rather than evaluate the condition.
+
+## Suppress a warning
+
+If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.
+
+```csharp
+#pragma warning disable MSTEST0070
+// The code that's violating the rule is on this line.
+#pragma warning restore MSTEST0070
+```
+
+To disable the rule for a file, folder, or project, set its severity to `none` in the [configuration file](../../../fundamentals/code-analysis/configuration-files.md).
+
+```ini
+[*.{cs,vb}]
+dotnet_diagnostic.MSTEST0070.severity = none
+```
+
+For more information, see [How to suppress code analysis warnings](../../../fundamentals/code-analysis/suppress-warnings.md).

docs/core/testing/mstest-analyzers/overview.md

@@ -278,6 +278,7 @@ Related documentation: [Configure MSTest](../unit-testing-mstest-configure.md),
 | [MSTEST0061](mstest0061.md) | Usage | Use OSCondition attribute instead of runtime check | Info |
 | [MSTEST0062](mstest0062.md) | Usage | Avoid out/ref test method parameters | Warning |
 | [MSTEST0063](mstest0063.md) | Usage | Test class should have valid constructor | Warning |
+| [MSTEST0070](mstest0070.md) | Usage | \[MemberCondition] arguments should be valid | Warning |
 
 \* Escalated to Error in `Recommended` and `All` modes.
 

docs/core/testing/mstest-analyzers/usage-rules.md

@@ -59,6 +59,7 @@ Usage rules support proper usage of MSTest attributes, methods, and patterns. Th
 | [MSTEST0061](mstest0061.md) | Use OSCondition attribute instead of runtime check. | Info | Yes |
 | [MSTEST0062](mstest0062.md) | Avoid out/ref test method parameters. | Warning | Yes |
 | [MSTEST0063](mstest0063.md) | Test class should have valid constructor. | Warning | No |
+| [MSTEST0070](mstest0070.md) | \[MemberCondition] arguments should be valid. | Warning | No |
 
 \* Escalated to Error in `Recommended` and `All` modes.
 
@@ -141,6 +142,7 @@ Rules for asynchronous test code:
 - **[MSTEST0059](mstest0059.md)**: Don't use both Parallelize and DoNotParallelize.
 - **[MSTEST0060](mstest0060.md)**: Avoid duplicate TestMethodAttribute.
 - **[MSTEST0061](mstest0061.md)**: Use OSCondition attribute for platform checks.
+- **[MSTEST0070](mstest0070.md)**: `[MemberCondition]` arguments must reference valid members.
 
 ## Related documentation
 

docs/navigate/devops-testing/toc.yml

@@ -222,6 +222,8 @@ items:
                         href: ../../core/testing/mstest-analyzers/mstest0062.md
                       - name: MSTEST0063
                         href: ../../core/testing/mstest-analyzers/mstest0063.md
+                      - name: MSTEST0070
+                        href: ../../core/testing/mstest-analyzers/mstest0070.md
               - name: Migration
                 items:
                   - name: Migrate from MSTest v1 to v3