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Merged
JerrettDavis merged 1 commit into from
May 31, 2026
Merged

test: harden memento generator coverage #467

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41 changes: 31 additions & 10 deletions src/PatternKit.Generators/MementoGenerator.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -348,17 +348,20 @@ private string GenerateMementoStruct(TypeInfo typeInfo, SourceProductionContext
}
sb.AppendLine();

// Constructor
sb.Append($" private {typeInfo.TypeName}Memento(");
sb.Append(string.Join(", ", typeInfo.Members.Select(m => $"{m.Type} {ToCamelCase(m.Name)}")));
sb.AppendLine(")");
sb.AppendLine(" {");
foreach (var member in typeInfo.Members)
if (typeInfo.Members.Count > 0)
{
sb.AppendLine($" {member.Name} = {ToCamelCase(member.Name)};");
// Constructor
sb.Append($" private {typeInfo.TypeName}Memento(");
sb.Append(string.Join(", ", typeInfo.Members.Select(m => $"{m.Type} {ToCamelCase(m.Name)}")));
sb.AppendLine(")");
sb.AppendLine(" {");
foreach (var member in typeInfo.Members)
{
sb.AppendLine($" {member.Name} = {ToCamelCase(member.Name)};");
}
sb.AppendLine(" }");
sb.AppendLine();
}
sb.AppendLine(" }");
sb.AppendLine();

// Capture method
GenerateCaptureMethod(sb, typeInfo);
Expand Down Expand Up @@ -449,7 +452,7 @@ private void GenerateRestoreNewMethod(StringBuilder sb, TypeInfo typeInfo, Sourc
else
{
// Fall back to object initializer
sb.AppendLine("()");
AppendRecordFallbackConstructor(sb, typeInfo);
sb.AppendLine(" {");
foreach (var member in typeInfo.Members)
{
Expand Down Expand Up @@ -487,6 +490,24 @@ private void GenerateRestoreNewMethod(StringBuilder sb, TypeInfo typeInfo, Sourc
sb.AppendLine(" }");
}

private static void AppendRecordFallbackConstructor(StringBuilder sb, TypeInfo typeInfo)
{
var fallbackCtor = typeInfo.TypeSymbol.Constructors
.Where(c => !c.IsStatic && c.DeclaredAccessibility == Accessibility.Public)
.OrderBy(c => c.Parameters.Length)
.FirstOrDefault();

if (fallbackCtor is null || fallbackCtor.Parameters.Length == 0)
{
sb.AppendLine("()");
return;
}

sb.Append("(");
sb.Append(string.Join(", ", fallbackCtor.Parameters.Select(_ => "default!")));
sb.AppendLine(")");
}
Comment on lines +493 to +509

private void GenerateInPlaceRestoreMethod(StringBuilder sb, TypeInfo typeInfo)
{
sb.AppendLine($" /// <summary>Restores the memento state to an existing originator instance (in-place).</summary>");
Expand Down
35 changes: 35 additions & 0 deletions test/PatternKit.Generators.Tests/DecoratorGeneratorTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -1206,4 +1206,39 @@ string Format(
var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}

[Scenario("Diagnostic PKDEC004 InaccessiblePropertyDeclaration")]
[Fact]
public void Diagnostic_PKDEC004_InaccessiblePropertyDeclaration()
{
const string source = """
using PatternKit.Generators.Decorator;

namespace TestNamespace;

[GenerateDecorator]
public abstract class SecretRepository
{
private protected abstract string Confidential { get; }
public abstract string Visible { get; }
}
""";

var comp = RoslynTestHelpers.CreateCompilation(source, nameof(Diagnostic_PKDEC004_InaccessiblePropertyDeclaration));
var gen = new DecoratorGenerator();
_ = RoslynTestHelpers.Run(comp, gen, out var result, out var updated);

ScenarioExpect.Contains(result.Results.SelectMany(r => r.Diagnostics), d => d.Id == "PKDEC004" && d.GetMessage().Contains("Confidential"));

var generatedSource = result.Results
.SelectMany(r => r.GeneratedSources)
.Single(gs => gs.HintName == "TestNamespace_SecretRepository.Decorator.g.cs")
.SourceText.ToString();

ScenarioExpect.Contains("Visible", generatedSource);
ScenarioExpect.DoesNotContain("Confidential", generatedSource);

var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}
}
188 changes: 188 additions & 0 deletions test/PatternKit.Generators.Tests/MementoGeneratorTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -399,4 +399,192 @@ public partial record class EditorState(string Text, int Cursor);
ScenarioExpect.Matches(@"private\s+const\s+int\s+MaxCapacity\s*=\s*50", caretakerSource);
ScenarioExpect.Matches(@"if\s*\(\s*_states\.Count\s*>\s*MaxCapacity\s*\)", caretakerSource);
}

[Scenario("ExplicitCaptureStrategies AreAcceptedWithoutReferenceWarnings")]
[Fact]
public void ExplicitCaptureStrategies_AreAcceptedWithoutReferenceWarnings()
{
const string source = """
using PatternKit.Generators;
using System.Collections.Generic;

namespace TestNamespace;

[Memento]
public partial class Document
{
[MementoStrategy(MementoCaptureStrategy.ByReference)]
public List<string> Tags { get; set; } = new();

[MementoStrategy(MementoCaptureStrategy.Clone)]
public CloneableBuffer Cloneable { get; set; } = new();

[MementoStrategy(MementoCaptureStrategy.DeepCopy)]
public CloneableBuffer Deep { get; set; } = new();

[MementoStrategy(MementoCaptureStrategy.Custom)]
public CloneableBuffer Custom { get; set; } = new();
}

public sealed class CloneableBuffer
{
}
""";

var comp = RoslynTestHelpers.CreateCompilation(source, nameof(ExplicitCaptureStrategies_AreAcceptedWithoutReferenceWarnings));
var gen = new MementoGenerator();
_ = RoslynTestHelpers.Run(comp, gen, out var result, out var updated);

ScenarioExpect.DoesNotContain(result.Results.SelectMany(r => r.Diagnostics), d => d.Id == "PKMEM003");

var mementoSource = result.Results
.SelectMany(r => r.GeneratedSources)
.Single(gs => gs.HintName == "Document.Memento.g.cs")
.SourceText.ToString();

ScenarioExpect.Contains("global::System.Collections.Generic.List<string> Tags", mementoSource);
ScenarioExpect.Contains("global::TestNamespace.CloneableBuffer Cloneable", mementoSource);
ScenarioExpect.Contains("global::TestNamespace.CloneableBuffer Deep", mementoSource);
ScenarioExpect.Contains("global::TestNamespace.CloneableBuffer Custom", mementoSource);

var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}

[Scenario("RecordWithoutPrimaryConstructor RestoresWithObjectInitializer")]
[Fact]
public void RecordWithoutPrimaryConstructor_RestoresWithObjectInitializer()
{
const string source = """
using PatternKit.Generators;

namespace TestNamespace;

[Memento]
public partial record class EditorState
{
public string Text { get; init; } = "";
public int Cursor { get; init; }
}
""";

var comp = RoslynTestHelpers.CreateCompilation(source, nameof(RecordWithoutPrimaryConstructor_RestoresWithObjectInitializer));
var gen = new MementoGenerator();
_ = RoslynTestHelpers.Run(comp, gen, out var result, out var updated);

ScenarioExpect.All(result.Results, r => ScenarioExpect.Empty(r.Diagnostics));

var mementoSource = result.Results
.SelectMany(r => r.GeneratedSources)
.Single(gs => gs.HintName == "EditorState.Memento.g.cs")
.SourceText.ToString();

ScenarioExpect.Contains("return new global::TestNamespace.EditorState()", mementoSource);
ScenarioExpect.Contains("Text = this.Text,", mementoSource);
ScenarioExpect.Contains("Cursor = this.Cursor,", mementoSource);

var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}

[Scenario("ClassWithOnlyReadonlyMembers RestoresWithDefaultConstructor")]
[Fact]
public void ClassWithOnlyReadonlyMembers_RestoresWithDefaultConstructor()
{
const string source = """
using PatternKit.Generators;

namespace TestNamespace;

[Memento]
public partial class ReadOnlyState
{
public readonly int Version;
}
""";

var comp = RoslynTestHelpers.CreateCompilation(source, nameof(ClassWithOnlyReadonlyMembers_RestoresWithDefaultConstructor));
var gen = new MementoGenerator();
_ = RoslynTestHelpers.Run(comp, gen, out var result, out var updated);

ScenarioExpect.All(result.Results, r => ScenarioExpect.Empty(r.Diagnostics));

var mementoSource = result.Results
.SelectMany(r => r.GeneratedSources)
.Single(gs => gs.HintName == "ReadOnlyState.Memento.g.cs")
.SourceText.ToString();

ScenarioExpect.Contains("public int Version { get; }", mementoSource);
ScenarioExpect.Contains("return new global::TestNamespace.ReadOnlyState();", mementoSource);
ScenarioExpect.DoesNotContain("originator.Version = this.Version;", mementoSource);

var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}

[Scenario("RecordWithNoCapturedMembers RestoresWithDefaultConstructor")]
[Fact]
public void RecordWithNoCapturedMembers_RestoresWithDefaultConstructor()
{
const string source = """
using PatternKit.Generators;

namespace TestNamespace;

[Memento]
public partial record class EmptyState;
""";

var comp = RoslynTestHelpers.CreateCompilation(source, nameof(RecordWithNoCapturedMembers_RestoresWithDefaultConstructor));
var gen = new MementoGenerator();
_ = RoslynTestHelpers.Run(comp, gen, out var result, out var updated);

ScenarioExpect.All(result.Results, r => ScenarioExpect.Empty(r.Diagnostics));

var mementoSource = result.Results
.SelectMany(r => r.GeneratedSources)
.Single(gs => gs.HintName == "EmptyState.Memento.g.cs")
.SourceText.ToString();

ScenarioExpect.DoesNotContain("private EmptyStateMemento()", mementoSource);
ScenarioExpect.Contains("return new global::TestNamespace.EmptyState();", mementoSource);

var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}

[Scenario("RecordWithIgnoredPrimaryConstructorMember FallsBackToObjectInitializer")]
[Fact]
public void RecordWithIgnoredPrimaryConstructorMember_FallsBackToObjectInitializer()
{
const string source = """
using PatternKit.Generators;

namespace TestNamespace;

[Memento]
public partial record class FilteredState([property: MementoIgnore] string Raw)
{
public string Name { get; init; } = Raw;
}
""";

var comp = RoslynTestHelpers.CreateCompilation(source, nameof(RecordWithIgnoredPrimaryConstructorMember_FallsBackToObjectInitializer));
var gen = new MementoGenerator();
_ = RoslynTestHelpers.Run(comp, gen, out var result, out var updated);

ScenarioExpect.All(result.Results, r => ScenarioExpect.Empty(r.Diagnostics));

var mementoSource = result.Results
.SelectMany(r => r.GeneratedSources)
.Single(gs => gs.HintName == "FilteredState.Memento.g.cs")
.SourceText.ToString();

ScenarioExpect.Contains("return new global::TestNamespace.FilteredState(default!)", mementoSource);
ScenarioExpect.Contains("Name = this.Name,", mementoSource);
ScenarioExpect.DoesNotContain("Raw = this.Raw", mementoSource);

var emit = updated.Emit(Stream.Null);
ScenarioExpect.True(emit.Success, string.Join("\n", emit.Diagnostics));
}
}
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