Improve diagnostics, add unit tests

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/AnalyzerReleases.Shipped.md

@@ -32,3 +32,4 @@ MVVMTK0022 | CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator
 MVVMTK0023 | CommunityToolkit.Mvvm.SourceGenerators.ICommandGenerator | Error | See https://aka.ms/mvvmtoolkit/error
 MVVMTK0024 | CommunityToolkit.Mvvm.SourceGenerators.ICommandGenerator | Error | See https://aka.ms/mvvmtoolkit/error
 MVVMTK0025 | CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator | Error | See https://aka.ms/mvvmtoolkit/error
+MVVMTK0026 | CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator | Error | See https://aka.ms/mvvmtoolkit/error

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.Execute.cs

@@ -152,7 +152,7 @@ internal static class Execute
                 }
             }
 
-            // Log the diagnostics if needed
+            // Log the diagnostic for missing ObservableValidator, if needed
             if (hasAnyValidationAttributes &&
                 !fieldSymbol.ContainingType.InheritsFromFullyQualifiedName("global::CommunityToolkit.Mvvm.ComponentModel.ObservableValidator"))
             {
@@ -164,6 +164,16 @@ internal static class Execute
                     forwardedAttributes.Count);
             }
 
+            // Log the diagnostic for missing validation attributes, if any
+            if (alsoValidateProperty && !hasAnyValidationAttributes)
+            {
+                builder.Add(
+                    MissingValidationAttributesForAlsoValidatePropertyError,
+                    fieldSymbol,
+                    fieldSymbol.ContainingType,
+                    fieldSymbol.Name);
+            }
+
             diagnostics = builder.ToImmutable();
 
             return new(

CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/DiagnosticDescriptors.cs

@@ -409,6 +409,22 @@ internal static class DiagnosticDescriptors
         category: typeof(ObservablePropertyGenerator).FullName,
         defaultSeverity: DiagnosticSeverity.Error,
         isEnabledByDefault: true,
-        description: "Cannot apply [AlsoValidateProperty] to field that are declared in a type that doesn't inherit from ObservableValidator.",
+        description: "Cannot apply [AlsoValidateProperty] to fields that are declared in a type that doesn't inherit from ObservableValidator.",
+        helpLinkUri: "https://aka.ms/mvvmtoolkit");
+
+    /// <summary>
+    /// Gets a <see cref="DiagnosticDescriptor"/> indicating when the target field uses [AlsoValidateProperty] but has no validation attributes.
+    /// <para>
+    /// Format: <c>"The field {0}.{1} cannot be annotated with [AlsoValidateProperty], as it doesn't have any validation attributes to use during validation"</c>.
+    /// </para>
+    /// </summary>
+    public static readonly DiagnosticDescriptor MissingValidationAttributesForAlsoValidatePropertyError = new DiagnosticDescriptor(
+        id: "MVVMTK0026",
+        title: "Missing validation attributes",
+        messageFormat: "The field {0}.{1} cannot be annotated with [AlsoValidateProperty], as it doesn't have any validation attributes to use during validation",
+        category: typeof(ObservablePropertyGenerator).FullName,
+        defaultSeverity: DiagnosticSeverity.Error,
+        isEnabledByDefault: true,
+        description: "Cannot apply [AlsoValidateProperty] to fields that don't have any validation attributes to use during validation.",
         helpLinkUri: "https://aka.ms/mvvmtoolkit");
 }

tests/CommunityToolkit.Mvvm.SourceGenerators.UnitTests/Test_SourceGeneratorsDiagnostics.cs

@@ -192,7 +192,7 @@ public partial class SampleViewModel
     }
 
     [TestMethod]
-    public void MissingObservableValidatorInheritanceError()
+    public void MissingObservableValidatorInheritanceForValidationAttributeError()
     {
         string source = @"
             using System.ComponentModel.DataAnnotations;
@@ -1188,6 +1188,48 @@ public partial class MyViewModel : ObservableObject
         VerifyGeneratedDiagnostics<ObservablePropertyGenerator>(source, "MVVMTK0024");
     }
 
+    [TestMethod]
+    public void MissingObservableValidatorInheritanceForAlsoValidatePropertyError()
+    {
+        string source = @"
+            using System.ComponentModel.DataAnnotations;
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp
+            {
+                [INotifyPropertyChanged]
+                public partial class SampleViewModel
+                {
+                    [ObservableProperty]
+                    [Required]
+                    [AlsoValidateProperty]
+                    private string name;
+                }
+            }";
+
+        VerifyGeneratedDiagnostics<ObservablePropertyGenerator>(source, "MVVMTK0006", "MVVMTK0025");
+    }
+
+    [TestMethod]
+    public void MissingValidationAttributesForAlsoValidatePropertyError()
+    {
+        string source = @"
+            using System.ComponentModel.DataAnnotations;
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp
+            {
+                public partial class SampleViewModel : ObservableValidator
+                {
+                    [ObservableProperty]
+                    [AlsoValidateProperty]
+                    private string name;
+                }
+            }";
+
+        VerifyGeneratedDiagnostics<ObservablePropertyGenerator>(source, "MVVMTK0026");
+    }
+
     /// <summary>
     /// Verifies the output of a source generator.
     /// </summary>
@@ -1232,7 +1274,7 @@ from assembly in AppDomain.CurrentDomain.GetAssemblies()
 
         HashSet<string> resultingIds = diagnostics.Select(diagnostic => diagnostic.Id).ToHashSet();
 
-        Assert.IsTrue(resultingIds.SetEquals(diagnosticsIds));
+        CollectionAssert.AreEquivalent(diagnosticsIds, resultingIds.ToArray());
 
         GC.KeepAlive(observableObjectType);
         GC.KeepAlive(validationAttributeType);