Added new rule MiKo_3122 that reports tests having more than 2 parameters

MiKo.Analyzer.Shared/Extensions/SyntaxTokenExtensions.cs

@@ -181,6 +181,7 @@ internal static SyntaxToken WithLeadingEmptyLines(this SyntaxToken value, int li
             var indicesToRemove = new Stack<int>();
 
             var count = trivia.Count;
+
             for (var index = 0; index < count; index++)
             {
                 var t = trivia[index];

MiKo.Analyzer.Shared/MiKo.Analyzer.Shared.projitems

@@ -284,6 +284,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3119_TestMethodsDoNotReturnCompletedTaskAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3120_UseValueInsteadOfItIsConditionMatcherAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3121_ObjectUnderTestIsNoInterfaceAnalyzer.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3201_InvertIfWhenFollowedByFewCodeLinesAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3202_InvertNegativeIfWhenReturningOnAllPathsAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Rules\Maintainability\MiKo_3203_InvertNegativeIfInsideBlockWhenFollowedBySingleCodeLinesAnalyzer.cs" />

MiKo.Analyzer.Shared/Resources.resx

@@ -4382,6 +4382,15 @@ Otherwise, when attempting to jump into the code, developers just end up at the
   <data name="MiKo_3121_Title" xml:space="preserve">
     <value>Tests should test concrete implementations and no interfaces</value>
   </data>
+  <data name="MiKo_3122_Description" xml:space="preserve">
+    <value>Test methods using more than 2 parameters most likely are combined tests. Such test are hard to read. Hence, to ease reading, these tests should be split into separate ones.</value>
+  </data>
+  <data name="MiKo_3122_MessageFormat" xml:space="preserve">
+    <value>Split into multiple tests so that you do not need more than 2 parameters</value>
+  </data>
+  <data name="MiKo_3122_Title" xml:space="preserve">
+    <value>Test methods should not use more than 2 parameters</value>
+  </data>
   <data name="MiKo_3201_CodeFixTitle" xml:space="preserve">
     <value>Invert if to simplify</value>
   </data>

MiKo.Analyzer.Shared/Rules/Maintainability/MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzer.cs

@@ -0,0 +1,32 @@
+using System.Collections.Generic;
+
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace MiKoSolutions.Analyzers.Rules.Maintainability
+{
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public sealed class MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzer : MaintainabilityAnalyzer
+    {
+        public const string Id = "MiKo_3122";
+
+        public MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzer() : base(Id)
+        {
+        }
+
+        protected override bool IsUnitTestAnalyzer => true;
+
+        protected override bool ShallAnalyze(IMethodSymbol symbol) => symbol.IsTestMethod();
+
+        protected override IEnumerable<Diagnostic> Analyze(IMethodSymbol symbol, Compilation compilation)
+        {
+            if (symbol.Parameters.Length > 2)
+            {
+                var syntax = symbol.GetSyntax<MethodDeclarationSyntax>();
+
+                yield return Issue(syntax.ParameterList);
+            }
+        }
+    }
+}

MiKo.Analyzer.Shared/Rules/Maintainability/MiKo_3221_CodeFixProvider.cs

@@ -30,10 +30,12 @@ protected override SyntaxNode GetUpdatedSyntax(Document document, SyntaxNode syn
                         {
                             case IdentifierNameSyntax identifier:
                                 nodes.Add(identifier);
+
                                 break;
 
                             case BaseExpressionSyntax _:
                                 nodes.Add(expression.Parent);
+
                                 break;
                         }
                     }

MiKo.Analyzer.Tests/Rules/Maintainability/MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzerTests.cs

@@ -0,0 +1,149 @@
+using Microsoft.CodeAnalysis.Diagnostics;
+
+using NUnit.Framework;
+
+using TestHelper;
+
+//// ncrunch: rdi off
+namespace MiKoSolutions.Analyzers.Rules.Maintainability
+{
+    [TestFixture]
+    public sealed class MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzerTests : CodeFixVerifier
+    {
+        [Test]
+        public void No_issue_is_reported_for_non_test_method_with_3_parameters() => No_issue_is_reported_for(@"
+using System;
+
+namespace Bla
+{
+    public class TestMe
+    {
+        public void DoSomething(int a, int b, int c) { }
+    }
+}
+");
+
+        [Test]
+        public void No_issue_is_reported_for_test_method_with_0_parameters() => No_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [Test]
+        public void SomeTest() { }
+    }
+}
+");
+
+        [Test]
+        public void No_issue_is_reported_for_test_method_with_1_parameter() => No_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [Test]
+        public void SomeTest([Values(42)] int a) { }
+    }
+}
+");
+
+        [Test]
+        public void No_issue_is_reported_for_test_method_with_2_parameters() => No_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [Test]
+        public void SomeTest([Values(1)] int a, [Values(2)] int b) { }
+    }
+}
+");
+
+        [Test]
+        public void An_issue_is_reported_for_test_method_with_3_parameters() => An_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [Test]
+        public void SomeTest([Values(1)] int a, [Values(2)] int b, [Values(3)] int c) { }
+    }
+}
+");
+
+        [Test]
+        public void No_issue_is_reported_for_test_case_method_with_1_parameter() => No_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [TestCase(42)]
+        public void SomeTest(int a) { }
+    }
+}
+");
+
+        [Test]
+        public void No_issue_is_reported_for_test_case_method_with_2_parameters() => No_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [TestCase(1, 2)]
+        public void SomeTest(int a, int b) { }
+    }
+}
+");
+
+        [Test]
+        public void An_issue_is_reported_for_test_case_method_with_3_parameters() => An_issue_is_reported_for(@"
+using System;
+
+using NUnit.Framework;
+
+namespace Bla
+{
+    [TestFixture]
+    public class TestMe
+    {
+        [TestCase(1, 2, 3)]
+        public void SomeTest(int a, int b, int c) { }
+    }
+}
+");
+
+        protected override string GetDiagnosticId() => MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzer.Id;
+
+        protected override DiagnosticAnalyzer GetObjectUnderTest() => new MiKo_3122_TestMethodsDoNotHaveMultipleParametersAnalyzer();
+    }
+}

README.md

@@ -15,7 +15,7 @@ Screenshots on how to use such analyzers can be found [here](https://learn.micro
 [![Build history](https://buildstats.info/appveyor/chart/RalfKoban/miko-analyzers)](https://ci.appveyor.com/project/RalfKoban/miko-analyzers/history)
 
 ## Available Rules
-The following tables lists all the 459 rules that are currently provided by the analyzer.
+The following tables lists all the 460 rules that are currently provided by the analyzer.
 
 ### Metrics
 |ID|Title|Enabled by default|CodeFix available|
@@ -395,6 +395,7 @@ The following tables lists all the 459 rules that are currently provided by the
 |MiKo_3119|Test methods should not simply return completed task|✓|✓|
 |MiKo_3120|Moq mocks should use values instead of 'It.Is<>(...)' condition matcher to verify exact values|✓|✓|
 |MiKo_3121|Tests should test concrete implementations and no interfaces|✓|\-|
+|MiKo_3122|Test methods should not use more than 2 parameters|✓|\-|
 |MiKo_3201|If statements can be inverted in short methods|✓|✓|
 |MiKo_3202|Use positive conditions when returning in all paths|✓|✓|
 |MiKo_3203|If-continue statements can be inverted when followed by single line|✓|✓|