extendable param files add a warning when referencing to a non-existe…

…nt .bicepparam file (#15338)

src/Bicep.Core.IntegrationTests/ParametersTests.cs

@@ -3,11 +3,13 @@
 using System.Diagnostics.CodeAnalysis;
 using Bicep.Core.Configuration;
 using Bicep.Core.Diagnostics;
+using Bicep.Core.FileSystem;
 using Bicep.Core.IntegrationTests.Extensibility;
 using Bicep.Core.Syntax;
 using Bicep.Core.TypeSystem.Types;
 using Bicep.Core.UnitTests;
 using Bicep.Core.UnitTests.Assertions;
+using Bicep.Core.UnitTests.FileSystem;
 using Bicep.Core.UnitTests.Utils;
 using FluentAssertions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -401,6 +403,84 @@ param arrayParam array
 """);
         }
 
+        [TestMethod]
+        public void Valid_extends_should_not_fail()
+        {
+            var result = CompilationHelper.CompileParams(
+              ("bicepconfig.json", @"
+                {
+                    ""experimentalFeaturesEnabled"": {
+                        ""extendableParamFiles"": true
+                    }
+                }
+              "),("parameters.bicepparam", @"
+                using 'main.bicep'
+                extends 'shared.bicepparam'
+              "),
+              ("shared.bicepparam", @"
+                using none
+              "),
+              ("main.bicep", @"
+              "));
+
+            result.ExcludingLinterDiagnostics().Should().NotHaveAnyDiagnostics();
+        }
+
+        [TestMethod]
+        public void Invalid_extends_reference_does_not_exist_should_fail()
+        {
+            var result = CompilationHelper.CompileParams(
+              ("bicepconfig.json", @"
+                {
+                    ""experimentalFeaturesEnabled"": {
+                        ""extendableParamFiles"": true
+                    }
+                }
+              "),
+              ("parameters.bicepparam", @"
+                using 'main.bicep'
+                extends 'does-not-exists.bicepparam'
+                param foo = ''
+              "),
+              ("main.bicep", @"
+                param foo string
+              "));
+
+            var path = InMemoryFileResolver.GetFileUri("/path/to/does-not-exists.bicepparam").LocalPath;
+
+            result.ExcludingLinterDiagnostics().Should().HaveDiagnostics(new[] {
+                ("BCP091", DiagnosticLevel.Error, $"An error occurred reading file. Could not find file '{path}'."),
+            });
+        }
+
+        [TestMethod]
+        public void Invalid_extends_reference_file_type_should_fail()
+        {
+            var result = CompilationHelper.CompileParams(
+              ("bicepconfig.json", @"
+                {
+                    ""experimentalFeaturesEnabled"": {
+                        ""extendableParamFiles"": true
+                    }
+                }
+              "),
+              ("parameters.json", @"
+                { ""foo"": ""bar"" }
+              "),
+              ("parameters.bicepparam", @"
+                using 'main.bicep'
+                extends 'parameters.json'
+                param foo = ''
+              "),
+              ("main.bicep", @"
+                param foo string
+              "));
+
+            result.ExcludingLinterDiagnostics().Should().HaveDiagnostics(new[] {
+                ("BCP404", DiagnosticLevel.Error, "The \"extends\" declaration is missing a bicepparam file path reference"),
+            });
+        }
+
         [TestMethod]
         public void Invalid_extends_and_more_than_one_extends_should_fail()
         {

src/Bicep.Core/Emit/EmitLimitationCalculator.cs

@@ -2,10 +2,12 @@
 // Licensed under the MIT License.
 
 using System.Collections.Immutable;
+using System.Diagnostics;
 using Bicep.Core.DataFlow;
 using Bicep.Core.Diagnostics;
 using Bicep.Core.Extensions;
 using Bicep.Core.Intermediate;
+using Bicep.Core.Navigation;
 using Bicep.Core.Parsing;
 using Bicep.Core.Semantics;
 using Bicep.Core.Semantics.Metadata;
@@ -505,11 +507,20 @@ private static ImmutableDictionary<ParameterAssignmentSymbol, ParameterAssignmen
 
             foreach (var extendsDeclaration in extendsDeclarations)
             {
-                if (model.TryGetReferencedModel(extendsDeclaration).IsSuccess(out var extendedModel) &&
-                    extendedModel is SemanticModel extendedSemanticModel)
+                var result = extendsDeclaration.TryGetReferencedModel(model.SourceFileGrouping, model.ModelLookup, b => b.ExtendsPathHasNotBeenSpecified());
+
+                if (result.IsSuccess(out var extendedModel, out var failure))
                 {
+                    if (extendedModel is not SemanticModel extendedSemanticModel)
+                    {
+                        throw new UnreachableException("We have already verified this is a .bicepparam file");
+                    }
                     generated.AddRange(extendedSemanticModel.EmitLimitationInfo.ParameterAssignments);
                 }
+                else
+                {
+                    diagnostics.Write(failure);
+                }
             }
 
             var evaluator = new ParameterAssignmentEvaluator(model);

src/Bicep.Core/Navigation/IArtifactReferenceSyntaxExtensions.cs

@@ -38,6 +38,7 @@ public static ResultWithDiagnostic<ISemanticModel> TryGetReferencedModel(
         var isValidReference = (reference, sourceFile) switch
         {
             (ExtendsDeclarationSyntax, BicepParamFile) => true,
+            (ExtendsDeclarationSyntax, _) => false,
             (_, BicepFile or ArmTemplateFile or TemplateSpecFile) => true,
             _ => false,
         };