Add parenthesis inside string interpolations (Fixes #115)

src/EntityFrameworkCore.Projectables.Generator/ExpressionSyntaxRewriter.cs

@@ -62,6 +62,23 @@ public ExpressionSyntaxRewriter(INamedTypeSymbol targetTypeSymbol, NullCondition
             return base.VisitInvocationExpression(node);
         }
 
+        public override SyntaxNode? VisitInterpolation(InterpolationSyntax node)
+        {
+            // Visit the expression first
+            var targetExpression = (ExpressionSyntax)Visit(node.Expression);
+
+            // Check if the expression already has parentheses
+            if (targetExpression is ParenthesizedExpressionSyntax)
+            {
+                return node.WithExpression(targetExpression);
+            }
+
+            // Create a new expression wrapped in parentheses
+            var newExpression = SyntaxFactory.ParenthesizedExpression(targetExpression);
+
+            return node.WithExpression(newExpression);
+        }
+
         public override SyntaxNode? VisitConditionalAccessExpression(ConditionalAccessExpressionSyntax node)
         {
             var targetExpression = (ExpressionSyntax)Visit(node.Expression);

tests/EntityFrameworkCore.Projectables.Generator.Tests/ProjectionExpressionGeneratorTests.GenericClassesWithContraints_AreRewritten.verified.txt

@@ -14,7 +14,7 @@ namespace EntityFrameworkCore.Projectables.Generated
     {
         static global::System.Linq.Expressions.Expression<global::System.Func<global::Foo.Entity<T, TEnum>, string>> Expression()
         {
-            return (global::Foo.Entity<T, TEnum> @this) => $"{@this.FirstName} {@this.LastName} {@this.SomeSubobject.SomeProp}";
+            return (global::Foo.Entity<T, TEnum> @this) => $"{(@this.FirstName)} {(@this.LastName)} {(@this.SomeSubobject.SomeProp)}";
         }
     }
 }

tests/EntityFrameworkCore.Projectables.Generator.Tests/ProjectionExpressionGeneratorTests.GenericClassesWithTypeContraints_AreRewritten.verified.txt

@@ -13,7 +13,7 @@ namespace EntityFrameworkCore.Projectables.Generated
     {
         static global::System.Linq.Expressions.Expression<global::System.Func<global::Foo.Entity<T>, string>> Expression()
         {
-            return (global::Foo.Entity<T> @this) => $"{@this.FirstName} {@this.LastName} {@this.SomeSubobject}";
+            return (global::Foo.Entity<T> @this) => $"{(@this.FirstName)} {(@this.LastName)} {(@this.SomeSubobject)}";
         }
     }
 }

tests/EntityFrameworkCore.Projectables.Generator.Tests/ProjectionExpressionGeneratorTests.StringInterpolationWithParenthesis_NoParenthesisAdded.verified.txt

@@ -0,0 +1,18 @@
+// <auto-generated/>
+#nullable disable
+using System;
+using System.Linq;
+using EntityFrameworkCore.Projectables;
+using Foo;
+
+namespace EntityFrameworkCore.Projectables.Generated
+{
+    [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
+    static class Foo_C_Status
+    {
+        static global::System.Linq.Expressions.Expression<global::System.Func<global::Foo.C, string>> Expression()
+        {
+            return (global::Foo.C @this) => @this.ValidationDate != null ? $"Validation date : ({(global::Foo.MyExtensions.ToDateString(@this.ValidationDate.Value))})" : "";
+        }
+    }
+}

tests/EntityFrameworkCore.Projectables.Generator.Tests/ProjectionExpressionGeneratorTests.StringInterpolationWithStaticCall_IsBeingRewritten.verified.txt

@@ -0,0 +1,18 @@
+// <auto-generated/>
+#nullable disable
+using System;
+using System.Linq;
+using EntityFrameworkCore.Projectables;
+using Foo;
+
+namespace EntityFrameworkCore.Projectables.Generated
+{
+    [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
+    static class Foo_C_Status
+    {
+        static global::System.Linq.Expressions.Expression<global::System.Func<global::Foo.C, string>> Expression()
+        {
+            return (global::Foo.C @this) => @this.ValidationDate != null ? $"Validation date : ({(global::Foo.MyExtensions.ToDateString(@this.ValidationDate.Value))})" : "";
+        }
+    }
+}

tests/EntityFrameworkCore.Projectables.Generator.Tests/ProjectionExpressionGeneratorTests.cs

@@ -778,6 +778,66 @@ static class C {
 
             return Verifier.Verify(result.GeneratedTrees[0].ToString());
         }
+
+        [Fact]
+        public Task StringInterpolationWithStaticCall_IsBeingRewritten()
+        {
+            var compilation = CreateCompilation(@"
+using System;
+using System.Linq;
+using EntityFrameworkCore.Projectables;
+
+namespace Foo {
+    static class MyExtensions {
+        public static string ToDateString(this DateTime date) => date.ToString(""dd/MM/yyyy"");
+    }
+
+    class C {
+        public DateTime? ValidationDate { get; set; }
+
+        [Projectable]
+        public string Status => ValidationDate != null ? $""Validation date : ({ValidationDate.Value.ToDateString()})"" : """";
+    }
+}
+");
+
+            var result = RunGenerator(compilation);
+
+            Assert.Empty(result.Diagnostics);
+            Assert.Single(result.GeneratedTrees);
+
+            return Verifier.Verify(result.GeneratedTrees[0].ToString());
+        }
+
+        [Fact]
+        public Task StringInterpolationWithParenthesis_NoParenthesisAdded()
+        {
+            var compilation = CreateCompilation(@"
+using System;
+using System.Linq;
+using EntityFrameworkCore.Projectables;
+
+namespace Foo {
+    static class MyExtensions {
+        public static string ToDateString(this DateTime date) => date.ToString(""dd/MM/yyyy"");
+    }
+
+    class C {
+        public DateTime? ValidationDate { get; set; }
+
+        [Projectable]
+        public string Status => ValidationDate != null ? $""Validation date : ({(ValidationDate.Value.ToDateString())})"" : """";
+    }
+}
+");
+
+            var result = RunGenerator(compilation);
+
+            Assert.Empty(result.Diagnostics);
+            Assert.Single(result.GeneratedTrees);
+
+            return Verifier.Verify(result.GeneratedTrees[0].ToString());
+        }
 
         [Fact]
         public Task NullableSimpleElementBinding_WithRewriteSupport_IsBeingRewritten()