Merge pull request #364 from manfred-brands/field_not_initialized

NonNullableFieldIsUninitializedSuppressor didn't work when there was a constructor
nunit · Feb 21, 2021 · d173b7c · d173b7c
2 parents 1e0017d + 4a61646
commit d173b7c
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Showing 2 changed files with 72 additions and 3 deletions.
diff --git a/...t.analyzers.tests/DiagnosticSuppressors/NonNullableFieldIsUninitializedSuppressorTests.cs b/...t.analyzers.tests/DiagnosticSuppressors/NonNullableFieldIsUninitializedSuppressorTests.cs
@@ -76,5 +76,38 @@ await DiagnosticsSuppressorAnalyzer.EnsureSuppressed(suppressor,
                 NonNullableFieldIsUninitializedSuppressor.NullableFieldInitializedInSetUp, testCode)
                 .ConfigureAwait(false);
         }
+
+        [TestCase("SetUp", "")]
+        [TestCase("OneTimeSetUp", "this.")]
+        public async Task FieldNotAssignedInConstructor(string attribute, string prefix)
+        {
+            var testCode = TestUtility.WrapMethodInClassNamespaceAndAddUsings(@$"
+                #nullable enable
+
+                private string testName;
+                private string nunitField;
+
+                public TestClass(string name)
+                {{
+                    {prefix}testName = name;
+                }}
+
+                [{attribute}]
+                public void Initialize()
+                {{
+                    {prefix}nunitField = string.Empty;
+                }}
+
+                [Test]
+                public void Test()
+                {{
+                    Assert.That({prefix}nunitField, Is.Not.Null);
+                }}
+            ");
+
+            await DiagnosticsSuppressorAnalyzer.EnsureSuppressed(suppressor,
+                NonNullableFieldIsUninitializedSuppressor.NullableFieldInitializedInSetUp, testCode)
+                .ConfigureAwait(false);
+        }
     }
 }
diff --git a/src/nunit.analyzers/DiagnosticSuppressors/NonNullableFieldIsUninitializedSuppressor.cs b/src/nunit.analyzers/DiagnosticSuppressors/NonNullableFieldIsUninitializedSuppressor.cs
@@ -1,8 +1,9 @@
 #if !NETSTANDARD1_6
 
-using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
+using System.Reflection;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
@@ -33,9 +34,44 @@ public override void ReportSuppressions(SuppressionAnalysisContext context)
                     continue;
                 }
 
-                string fieldName = node.ToString();
-
                 var classDeclaration = node.Ancestors().OfType<ClassDeclarationSyntax>().First();
+                var fieldDeclarations = classDeclaration.Members.OfType<FieldDeclarationSyntax>().ToArray();
+
+                string fieldName;
+
+                if (node is VariableDeclaratorSyntax variableDeclarator)
+                {
+                    fieldName = variableDeclarator.Identifier.Text;
+                }
+                else if (node is ConstructorDeclarationSyntax)
+                {
+                    // Unfortunately the actual field name is not directly accessible.
+                    // It seems to be in Argument[1], but that field is an internal property.
+                    // Resort to reflection.
+                    IReadOnlyList<object?>? arguments = (IReadOnlyList<object?>?)diagnostic.GetType()
+                        .GetProperty("Arguments", BindingFlags.NonPublic | BindingFlags.Instance)?
+                        .GetValue(diagnostic);
+                    if (arguments != null && arguments.Count == 2 && arguments[1] is string possibleFieldName)
+                    {
+                        fieldName = possibleFieldName;
+                    }
+                    else
+                    {
+                        // Don't know how to extract field name.
+                        continue;
+                    }
+                }
+                else
+                {
+                    continue;
+                }
+
+                // Verify that the name found is actually a field name.
+                if (!fieldDeclarations.SelectMany(x => x.Declaration.Variables).Any(x => x.Identifier.Text == fieldName))
+                {
+                    continue;
+                }
+
                 var methods = classDeclaration.Members.OfType<MethodDeclarationSyntax>().ToArray();
 
                 foreach (var method in methods)