MSTEST0030: Type contaning [TestMethod] should be a [TestClass] (#41625)

Author: engyebrahim

docs/core/testing/mstest-analyzers/mstest0030.md

@@ -0,0 +1,40 @@
+---
+title: "MSTEST0030: Type containing `[TestMethod]` should be marked with `[TestClass]`"
+description: "Learn about code analysis rule MSTEST0030: Type contaning `[TestMethod]` should be marked with `[TestClass]`, otherwise the test method will be silently ignored."
+ms.date: 07/02/2024
+f1_keywords:
+- MSTEST0030
+- TypeContainingTestMethodShouldBeATestClass
+helpviewer_keywords:
+- TypeContainingTestMethodShouldBeATestClass
+- MSTEST0030
+author: engyebrahim
+ms.author: enjieid
+---
+# MSTEST0030: Type containing `[TestMethod]` should be marked with `[TestClass]`
+
+| Property                            | Value                                                              |
+|-------------------------------------|--------------------------------------------------------------------|
+| **Rule ID**                         | MSTEST0030                                                         |
+| **Title**                           | Type containing `[TestMethod]` should be marked with `[TestClass]` |
+| **Category**                        | Usage                                                              |
+| **Fix is breaking or non-breaking** | Non-breaking                                                       |
+| **Enabled by default**              | Yes                                                                |
+| **Default severity**                | Info                                                               |
+| **Introduced in version**           | 3.5.0                                                              |
+
+## Cause
+
+Type contaning `[TestMethod]` should be marked with `[TestClass]`, otherwise the test method will be silently ignored.
+
+## Rule description
+
+MSTest considers test methods only on the context of a test class container (a class marked with [TestClass] or derived attribute) which could lead to some tests being silently ignored. If your class is supposed to represent common test behavior to be executed by children classes, it's recommended to mark the type as abstract to clarify the intent for other developers reading the code.
+
+## How to fix violations
+
+A non-abstract class contains test methods should be marked with '[TestClass]'.
+
+## When to suppress warnings
+
+It's safe to suppress the diagnostic if you are sure that your class is being inherited and that the tests declared on this class should only be run in the context of subclasses. Nonetheless, we recommend marking the class as abstract.

docs/navigate/devops-testing/toc.yml

@@ -143,6 +143,8 @@ items:
                     href: ../../core/testing/mstest-analyzers/mstest0024.md
                   - name: MSTEST0026
                     href: ../../core/testing/mstest-analyzers/mstest0026.md
+                  - name: MSTEST0030
+                    href: ../../core/testing/mstest-analyzers/mstest0030.md
       - name: Microsoft Testing Platform
         items:
           - name: Overview