WIP: Nameof function

src/Bicep.Core.IntegrationTests/Scenarios/NameofFunctionTests.cs

@@ -0,0 +1,179 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using Bicep.Core.UnitTests.Assertions;
+using Bicep.Core.UnitTests.Utils;
+using FluentAssertions.Execution;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Newtonsoft.Json.Linq;
+
+namespace Bicep.Core.IntegrationTests.Scenarios
+{
+    [TestClass]
+    public class NameofFunctionTests
+    {
+        [TestMethod]
+        public void NameofFunction_OnObjectProperty_ReturnsPropertyName()
+        {
+            var result = CompilationHelper.Compile("""
+var obj = {
+  prop: 'value'
+}
+output name string = nameof(obj.prop)
+""");
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", "prop");
+            }
+        }
+
+        [TestMethod]
+        public void NameofFunction_OnVariable_ReturnsVariableName()
+        {
+            var result = CompilationHelper.Compile("""
+var obj = {
+  prop: 'value'
+}
+output name string = nameof(obj)
+""");
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", "obj");
+            }
+        }
+
+        [TestMethod]
+        public void NameofFunction_OnParameter_ReturnsParameterName()
+        {
+            var result = CompilationHelper.Compile("""
+                                                   param test string
+                                                   output name string = nameof(test)
+                                                   """);
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", "test");
+            }
+        }
+
+        [TestMethod]
+        public void NameofFunction_OnResource_ReturnsResourceSymbolicName()
+        {
+            var result = CompilationHelper.Compile("""
+resource myStorage 'Microsoft.Storage/storageAccounts@2019-06-01' = {
+  name: 'storage123'
+}
+
+output name string = nameof(myStorage)
+""");
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", "myStorage");
+            }
+        }
+
+        [TestMethod]
+        public void NameofFunction_OnChildResource_ReturnsResourceSymbolicName()
+        {
+            var result = CompilationHelper.Compile("""
+resource sqlServer 'Microsoft.Sql/servers@2021-11-01' = {
+  name: 'sql-server-name'
+
+  resource primaryDb 'databases' = {
+    name: 'primary'
+  }
+}
+
+output name string = nameof(sqlServer::primaryDb)
+""");
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", "primaryDb");
+            }
+        }
+
+        [TestMethod]
+        public void NameofFunction_OnLoopedResource_ReturnsResourceSymbolicName()
+        {
+            var result = CompilationHelper.Compile("""
+
+var dbs = [
+  'primary'
+  'secondary'
+  'tertiary'
+]
+
+resource sqlServer 'Microsoft.Sql/servers@2021-11-01' = {
+  name: 'sql-server-name'
+
+  @batchSize(1)
+  resource databases 'databases' = [for db in dbs: {
+    name: db
+  }]
+}
+
+output name string = nameof(sqlServer::databases)
+""");
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", "databases");
+            }
+        }
+
+        [DataTestMethod]
+        [DataRow("name", "name")]
+        [DataRow("type", "type")]
+        [DataRow("location", "location")]
+        [DataRow("properties", "properties")]
+        [DataRow("properties.sku", "sku")]
+        public void NameofFunction_OnResourceProperty_ReturnsResourcePropertyName(string resourceProperty, string expectedValue)
+        {
+            var result = CompilationHelper.Compile($$"""
+ resource myStorage 'Microsoft.Storage/storageAccounts@2019-06-01' = {
+   name: 'storage123'
+ }
+
+ output name string = nameof(myStorage.{{resourceProperty}})
+
+ """);
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.outputs['name'].value", expectedValue);
+            }
+        }
+
+        [TestMethod]
+        public void UsingNameofFunction_ShouldNotGenerateDependsOnEntries()
+        {
+            var result = CompilationHelper.Compile("""
+resource myStorage 'Microsoft.Storage/storageAccounts@2019-06-01' = {
+  name: 'storage123'
+}
+
+resource sqlServer 'Microsoft.Sql/servers@2021-11-01' = {
+  name: nameof(myStorage)
+}
+""");
+
+            using (new AssertionScope())
+            {
+                result.Should().NotHaveAnyCompilationBlockingDiagnostics();
+                result.Template.Should().HaveValueAtPath("$.resources[?(@.type == 'Microsoft.Sql/servers')].name", "myStorage", "Nameof function should emit static string during compilation");
+                result.Template.Should().NotHaveValueAtPath("$.resources[?(@.type == 'Microsoft.Sql/servers')].dependsOn", "Depends on should not be generated for nameof function usage");
+            }
+        }
+    }
+}

src/Bicep.Core/Emit/ForSyntaxValidatorVisitor.cs

@@ -61,6 +61,7 @@ private enum PropertyLoopCapability
         private bool insideTopLevelDependsOn = false;
 
         private bool insideProperties = false;
+        private bool insideNameOfFunction = false;
 
         private ForSyntaxValidatorVisitor(SemanticModel semanticModel, IDiagnosticWriter diagnosticWriter)
         {
@@ -251,6 +252,13 @@ public override void VisitResourceAccessSyntax(ResourceAccessSyntax syntax)
             base.VisitResourceAccessSyntax(syntax);
         }
 
+        public override void VisitFunctionCallSyntax(FunctionCallSyntax syntax)
+        {
+            insideNameOfFunction = syntax.Name.IdentifierName == LanguageConstants.NameofFunctionName;
+            base.VisitFunctionCallSyntax(syntax);
+            insideNameOfFunction = false;
+        }
+
         protected override void VisitInternal(SyntaxBase node)
         {
             var previousIsPropertyLoopPotentiallyAllowed = this.isPropertyLoopPotentiallyAllowed;
@@ -285,7 +293,7 @@ private void ValidateDirectAccessToResourceOrModuleCollection(SyntaxBase variabl
             {
                 // we are inside a dependsOn property and the referenced symbol is a resource/module collection
                 var parent = this.semanticModel.Binder.GetParent(variableOrResourceAccessSyntax);
-                if (!this.insideTopLevelDependsOn && parent is not ArrayAccessSyntax)
+                if (!insideNameOfFunction && !this.insideTopLevelDependsOn && parent is not ArrayAccessSyntax)
                 {
                     // the parent is not array access, which means that someone is doing a direct reference to the collection
                     // NOTE(kylealbert): Direct access to resource collections:
@@ -295,11 +303,12 @@ private void ValidateDirectAccessToResourceOrModuleCollection(SyntaxBase variabl
                     //  1. Allowed in a variable declaration value
                     //  1. Allowed in an output value
                     var isValidResourceCollectionDirectAccessLocation =
-                        this.semanticModel.Features.SymbolicNameCodegenEnabled
-                        && this.loopLevel == 0
-                        && (this.insideProperties
-                            || this.currentOutputDeclarationSyntax != null
-                            || (this.currentVariableDeclarationSyntax != null && this.variableAccessForInlineCheck == null));
+                        (this.semanticModel.Features.SymbolicNameCodegenEnabled
+                         && this.loopLevel == 0
+                         && (this.insideProperties
+                             || this.currentOutputDeclarationSyntax != null
+                             || (this.currentVariableDeclarationSyntax != null && this.variableAccessForInlineCheck == null))
+                        );
 
                     if (!isValidResourceCollectionDirectAccessLocation)
                     {

src/Bicep.Core/Emit/ResourceDependencyVisitor.cs

@@ -16,6 +16,7 @@ public class ResourceDependencyVisitor : AstVisitor
         private Options? options;
         private readonly IDictionary<DeclaredSymbol, HashSet<ResourceDependency>> resourceDependencies;
         private DeclaredSymbol? currentDeclaration;
+        private bool insideNameofFunction;
 
 
         public struct Options
@@ -154,7 +155,7 @@ private IEnumerable<ResourceDependency> GetResourceDependencies(DeclaredSymbol d
 
         public override void VisitVariableAccessSyntax(VariableAccessSyntax syntax)
         {
-            if (currentDeclaration is null)
+            if (currentDeclaration is null || insideNameofFunction)
             {
                 return;
             }
@@ -193,7 +194,7 @@ public override void VisitVariableAccessSyntax(VariableAccessSyntax syntax)
 
         public override void VisitResourceAccessSyntax(ResourceAccessSyntax syntax)
         {
-            if (currentDeclaration is null)
+            if (currentDeclaration is null || insideNameofFunction)
             {
                 return;
             }
@@ -282,6 +283,13 @@ public override void VisitObjectPropertySyntax(ObjectPropertySyntax propertySynt
             base.VisitObjectPropertySyntax(propertySyntax);
         }
 
+        public override void VisitFunctionCallSyntax(FunctionCallSyntax syntax)
+        {
+            insideNameofFunction = syntax.Name.IdentifierName == LanguageConstants.NameofFunctionName;
+            base.VisitFunctionCallSyntax(syntax);
+            insideNameofFunction = false;
+        }
+
         private bool IsTopLevelPropertyOfCurrentDeclaration(ObjectPropertySyntax propertySyntax)
         {
             SyntaxBase? declaringSyntax = this.currentDeclaration switch

src/Bicep.Core/LanguageConstants.cs

@@ -196,6 +196,8 @@ public static class LanguageConstants
         public const string StringHoleClose = "}";
 
         public const string AnyFunction = "any";
+        public const string NameofFunctionName = "nameof";
+
         public static readonly TypeSymbol Any = new AnyType();
         public static readonly TypeSymbol Never = new UnionType("never", []);
 

src/Bicep.Core/Semantics/Namespaces/SystemNamespaceType.cs

@@ -1053,6 +1053,39 @@ TypeSymbol type when TypeCollapser.TryCollapse(type) is TypeSymbol collapsed =>
                         return new(LanguageConstants.Object);
                     }, LanguageConstants.Object)
                     .Build();
+
+                yield return new FunctionOverloadBuilder(LanguageConstants.NameofFunctionName)
+                    .WithGenericDescription("Returns the name of the specified parameter, variable, or resource.")
+                    .WithRequiredParameter("symbol", LanguageConstants.Any, "The parameter, variable, or resource to retrieve the name of.")
+                    .WithReturnResultBuilder((model, diagnostics, call, argumentTypes) =>
+                    {
+                        var x = call.Arguments[0].Expression switch
+                        {
+                            VariableAccessSyntax variableAccess => variableAccess.Name.IdentifierName,
+                            PropertyAccessSyntax propertyAccess => propertyAccess.PropertyName.IdentifierName,
+                            ResourceAccessSyntax resourceAccess => resourceAccess.ResourceName.IdentifierName,
+                            ModuleDeclarationSyntax moduleDeclaration => moduleDeclaration.Name.IdentifierName,
+                            _ => null,
+                        };
+                        if (x is null)
+                        {
+                            return new(ErrorType.Create(DiagnosticBuilder.ForPosition(call.Arguments[0]).CompileTimeConstantRequired()));
+                        }
+                        return new(new StringLiteralType(x, TypeSymbolValidationFlags.Default));
+                    }, LanguageConstants.String)
+                    .WithEvaluator(expression =>
+                    {
+                        var x = expression.Parameters[0].SourceSyntax switch
+                        {
+                            VariableAccessSyntax variableAccess => variableAccess.Name.IdentifierName,
+                            PropertyAccessSyntax propertyAccess => propertyAccess.PropertyName.IdentifierName,
+                            ResourceAccessSyntax resourceAccess => resourceAccess.ResourceName.IdentifierName,
+                            ModuleDeclarationSyntax moduleDeclaration => moduleDeclaration.Name.IdentifierName,
+                            _ => string.Empty,
+                        };
+                        return new StringLiteralExpression(expression.Parameters[0].SourceSyntax, x);
+                    })
+                    .Build();
             }
 
             static IEnumerable<FunctionOverload> GetParamsFilePermittedOverloads()

src/Bicep.Core/Syntax/AstVisitor.cs

@@ -293,6 +293,7 @@ public override void VisitParenthesizedExpressionSyntax(ParenthesizedExpressionS
 
         public override void VisitFunctionCallSyntax(FunctionCallSyntax syntax)
         {
+
             this.Visit(syntax.Name);
             this.VisitNodes(syntax.Children);
         }

src/Bicep.Core/TypeSystem/DeployTimeConstantDirectViolationVisitor.cs

@@ -74,7 +74,6 @@ public override void VisitResourceAccessSyntax(ResourceAccessSyntax syntax)
         public override void VisitFunctionCallSyntax(FunctionCallSyntax syntax)
         {
             this.FlagIfFunctionRequiresInlining(syntax);
-
             base.VisitFunctionCallSyntax(syntax);
         }
 

src/Bicep.Core/TypeSystem/DeployTimeConstantViolationVisitor.cs

@@ -33,8 +33,14 @@ public DeployTimeConstantViolationVisitor(
 
         protected ResourceTypeResolver ResourceTypeResolver { get; }
 
+        private bool insideNameofFunction;
+
         protected void FlagDeployTimeConstantViolation(SyntaxBase errorSyntax, DeclaredSymbol? accessedSymbol = null, ObjectType? accessedObjectType = null, IEnumerable<string>? variableDependencyChain = null, string? violatingPropertyName = null)
         {
+            if (insideNameofFunction)
+            {
+                return;
+            }
             var accessedSymbolName = accessedSymbol?.Name;
             var accessiblePropertyNames = GetAccessiblePropertyNames(accessedSymbol, accessedObjectType);
 
@@ -95,5 +101,12 @@ ForSyntax forSyntax when ErrorSyntaxInForBodyOfVariable(forSyntax, errorSyntax)
 
             return accessiblePropertyNames;
         }
+
+        public override void VisitFunctionCallSyntax(FunctionCallSyntax syntax)
+        {
+            insideNameofFunction = syntax.Name.IdentifierName == LanguageConstants.NameofFunctionName;
+            base.VisitFunctionCallSyntax(syntax);
+            insideNameofFunction = false;
+        }
     }
 }