feat: Added ConfigFile to simplify AnalyzerConfigFile creation.

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ConfigFile.cs

@@ -0,0 +1,100 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Microsoft.CodeAnalysis.Testing
+{
+    public class ConfigFile : Dictionary<string, Dictionary<string, string>>
+    {
+        public string FileName { get; }
+
+        public Dictionary<string, string> Preamble { get; } = new Dictionary<string, string>();
+
+        public ConfigFile(string fileName)
+        {
+            FileName = fileName ?? throw new ArgumentNullException(nameof(fileName));
+        }
+
+        public new string this[string globalKey]
+        {
+            get
+            {
+                return Preamble[globalKey];
+            }
+
+            set
+            {
+                Preamble[globalKey] = value;
+            }
+        }
+
+        public string this[string sectionKey, string key]
+        {
+            get
+            {
+                if (!TryGetValue(sectionKey, out var values))
+                {
+                    values = new Dictionary<string, string>();
+                    base[sectionKey] = values;
+                }
+
+                return values[key];
+            }
+
+            set
+            {
+                if (!TryGetValue(sectionKey, out var values))
+                {
+                    values = new Dictionary<string, string>();
+                    base[sectionKey] = values;
+                }
+
+                values[key] = value;
+            }
+        }
+
+        public void Add(string globalKey, string value)
+        {
+            Preamble.Add(globalKey, value);
+        }
+
+        public void Add(string sectionKey, string key, string value)
+        {
+            if (!TryGetValue(sectionKey, out var values))
+            {
+                values = new Dictionary<string, string>();
+                base[sectionKey] = values;
+            }
+
+            values.Add(key, value);
+        }
+
+        private static string ToString(Dictionary<string, string> dictionary)
+        {
+            return string.Join(
+                Environment.NewLine,
+                dictionary.Select(pair => $@"{pair.Key} = {pair.Value}"));
+        }
+
+        private static string ToString(Dictionary<string, Dictionary<string, string>> dictionary)
+        {
+            return string.Join(
+                Environment.NewLine,
+                dictionary.Select(pair => $@"[{pair.Key}]
+{ToString(pair.Value)}"));
+        }
+
+        public override string ToString()
+        {
+            return @$"
+{ToString(Preamble)}
+
+{ToString(this)}
+";
+        }
+    }
+}

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ConfigFileCollection.cs

@@ -0,0 +1,17 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Text;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.Testing
+{
+    public class ConfigFileCollection : SourceFileCollection
+    {
+        public void Add(ConfigFile file)
+        {
+            Add((file.FileName, SourceText.From(file.ToString(), Encoding.UTF8)));
+        }
+    }
+}

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/EditorConfigFile.cs

@@ -0,0 +1,14 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CodeAnalysis.Testing
+{
+    public class EditorConfigFile : ConfigFile
+    {
+        public EditorConfigFile()
+            : base("/.editorconfig")
+        {
+        }
+    }
+}

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/GlobalConfigFile.cs

@@ -0,0 +1,14 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CodeAnalysis.Testing
+{
+    public class GlobalConfigFile : ConfigFile
+    {
+        public GlobalConfigFile()
+            : base("/.globalconfig")
+        {
+        }
+    }
+}

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/ProjectState.cs

@@ -69,7 +69,7 @@ internal ProjectState(ProjectState sourceState)
 
         public SourceFileCollection AdditionalFiles { get; } = new SourceFileCollection();
 
-        public SourceFileCollection AnalyzerConfigFiles { get; } = new SourceFileCollection();
+        public ConfigFileCollection AnalyzerConfigFiles { get; } = new ConfigFileCollection();
 
         public List<Func<IEnumerable<(string filename, SourceText content)>>> AdditionalFilesFactories { get; } = new List<Func<IEnumerable<(string filename, SourceText content)>>>();
 

src/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing/PublicAPI.Unshipped.txt

@@ -49,6 +49,19 @@ Microsoft.CodeAnalysis.Testing.CompilerDiagnostics.Errors = 1 -> Microsoft.CodeA
 Microsoft.CodeAnalysis.Testing.CompilerDiagnostics.None = 0 -> Microsoft.CodeAnalysis.Testing.CompilerDiagnostics
 Microsoft.CodeAnalysis.Testing.CompilerDiagnostics.Suggestions = 3 -> Microsoft.CodeAnalysis.Testing.CompilerDiagnostics
 Microsoft.CodeAnalysis.Testing.CompilerDiagnostics.Warnings = 2 -> Microsoft.CodeAnalysis.Testing.CompilerDiagnostics
+Microsoft.CodeAnalysis.Testing.ConfigFile
+Microsoft.CodeAnalysis.Testing.ConfigFile.Add(string globalKey, string value) -> void
+Microsoft.CodeAnalysis.Testing.ConfigFile.Add(string sectionKey, string key, string value) -> void
+Microsoft.CodeAnalysis.Testing.ConfigFile.ConfigFile(string fileName) -> void
+Microsoft.CodeAnalysis.Testing.ConfigFile.FileName.get -> string
+Microsoft.CodeAnalysis.Testing.ConfigFile.Preamble.get -> System.Collections.Generic.Dictionary<string, string>
+Microsoft.CodeAnalysis.Testing.ConfigFile.this[string globalKey].get -> string
+Microsoft.CodeAnalysis.Testing.ConfigFile.this[string globalKey].set -> void
+Microsoft.CodeAnalysis.Testing.ConfigFile.this[string sectionKey, string key].get -> string
+Microsoft.CodeAnalysis.Testing.ConfigFile.this[string sectionKey, string key].set -> void
+Microsoft.CodeAnalysis.Testing.ConfigFileCollection
+Microsoft.CodeAnalysis.Testing.ConfigFileCollection.Add(Microsoft.CodeAnalysis.Testing.ConfigFile file) -> void
+Microsoft.CodeAnalysis.Testing.ConfigFileCollection.ConfigFileCollection() -> void
 Microsoft.CodeAnalysis.Testing.DefaultVerifier
 Microsoft.CodeAnalysis.Testing.DefaultVerifier.Context.get -> System.Collections.Immutable.ImmutableStack<string>
 Microsoft.CodeAnalysis.Testing.DefaultVerifier.DefaultVerifier() -> void
@@ -97,8 +110,12 @@ Microsoft.CodeAnalysis.Testing.DiagnosticResult.WithSpan(Microsoft.CodeAnalysis.
 Microsoft.CodeAnalysis.Testing.DiagnosticResult.WithSpan(Microsoft.CodeAnalysis.FileLinePositionSpan span, Microsoft.CodeAnalysis.Testing.DiagnosticLocationOptions options) -> Microsoft.CodeAnalysis.Testing.DiagnosticResult
 Microsoft.CodeAnalysis.Testing.DiagnosticResult.WithSpan(int startLine, int startColumn, int endLine, int endColumn) -> Microsoft.CodeAnalysis.Testing.DiagnosticResult
 Microsoft.CodeAnalysis.Testing.DiagnosticResult.WithSpan(string path, int startLine, int startColumn, int endLine, int endColumn) -> Microsoft.CodeAnalysis.Testing.DiagnosticResult
+Microsoft.CodeAnalysis.Testing.EditorConfigFile
+Microsoft.CodeAnalysis.Testing.EditorConfigFile.EditorConfigFile() -> void
 Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer
 Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer.EmptyDiagnosticAnalyzer() -> void
+Microsoft.CodeAnalysis.Testing.GlobalConfigFile
+Microsoft.CodeAnalysis.Testing.GlobalConfigFile.GlobalConfigFile() -> void
 Microsoft.CodeAnalysis.Testing.IVerifier
 Microsoft.CodeAnalysis.Testing.IVerifier.Empty<T>(string collectionName, System.Collections.Generic.IEnumerable<T> collection) -> void
 Microsoft.CodeAnalysis.Testing.IVerifier.Equal<T>(T expected, T actual, string message = null) -> void
@@ -153,7 +170,7 @@ Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalFiles.get -> Microsoft.Cod
 Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalFilesFactories.get -> System.Collections.Generic.List<System.Func<System.Collections.Generic.IEnumerable<(string filename, Microsoft.CodeAnalysis.Text.SourceText content)>>>
 Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalProjectReferences.get -> System.Collections.Generic.List<string>
 Microsoft.CodeAnalysis.Testing.ProjectState.AdditionalReferences.get -> Microsoft.CodeAnalysis.Testing.MetadataReferenceCollection
-Microsoft.CodeAnalysis.Testing.ProjectState.AnalyzerConfigFiles.get -> Microsoft.CodeAnalysis.Testing.SourceFileCollection
+Microsoft.CodeAnalysis.Testing.ProjectState.AnalyzerConfigFiles.get -> Microsoft.CodeAnalysis.Testing.ConfigFileCollection
 Microsoft.CodeAnalysis.Testing.ProjectState.AssemblyName.get -> string
 Microsoft.CodeAnalysis.Testing.ProjectState.DocumentationMode.get -> Microsoft.CodeAnalysis.DocumentationMode?
 Microsoft.CodeAnalysis.Testing.ProjectState.DocumentationMode.set -> void
@@ -240,6 +257,7 @@ abstract Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.DefaultFileExt.g
 abstract Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.GetDiagnosticAnalyzers() -> System.Collections.Generic.IEnumerable<Microsoft.CodeAnalysis.Diagnostics.DiagnosticAnalyzer>
 abstract Microsoft.CodeAnalysis.Testing.AnalyzerTest<TVerifier>.Language.get -> string
 abstract Microsoft.CodeAnalysis.Testing.CodeActionTest<TVerifier>.SyntaxKindType.get -> System.Type
+override Microsoft.CodeAnalysis.Testing.ConfigFile.ToString() -> string
 override Microsoft.CodeAnalysis.Testing.DiagnosticResult.ToString() -> string
 override Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer.Initialize(Microsoft.CodeAnalysis.Diagnostics.AnalysisContext context) -> void
 override Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer.SupportedDiagnostics.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.DiagnosticDescriptor>

tests/Microsoft.CodeAnalysis.Testing/Microsoft.CodeAnalysis.Analyzer.Testing.UnitTests/AnalyzerConfigFilesTests.cs

@@ -5,6 +5,7 @@
 #if !NETCOREAPP1_1 && !NET46
 
 using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Text;
 using System.Threading.Tasks;
@@ -97,13 +98,6 @@ public async Task TestDiagnosticInAnalyzerConfigFileWithCombinedSyntaxDuplicate(
         [Fact]
         public async Task TestDiagnosticInAnalyzerConfigFileBraceNotTreatedAsMarkup()
         {
-            var editorConfig = @"
-root = true
-
-[*]
-key = {|Literal:value|}
-";
-
             await new CSharpTest
             {
                 TestState =
@@ -112,13 +106,61 @@ public async Task TestDiagnosticInAnalyzerConfigFileBraceNotTreatedAsMarkup()
                     ExpectedDiagnostics = { new DiagnosticResult(HighlightBracesIfAnalyzerConfigMissingAnalyzer.Descriptor).WithLocation(1, 23) },
                     AnalyzerConfigFiles =
                     {
-                        ("/.editorconfig", SourceText.From(editorConfig, Encoding.UTF8)),
+                        new EditorConfigFile
+                        {
+                            ["root"] = "true",
+                            ["*", "key"] = "{|Literal:value|}",
+                        },
                     },
                     MarkupHandling = MarkupMode.None,
                 },
             }.RunAsync();
         }
 
+        [Fact]
+        public void AnalyzerConfigFileViaDictionarySyntaxEquivalentToManualCreation()
+        {
+            var expected = @"
+root = true
+
+[*]
+key = {|Literal:value|}
+";
+
+            var actual = new EditorConfigFile
+            {
+                ["root"] = "true",
+                ["*", "key"] = "{|Literal:value|}",
+            }.ToString();
+
+            Assert.Equal(expected, actual);
+        }
+
+        [Fact]
+        public void AnalyzerConfigFileViaAddSyntaxEquivalentToManualCreation()
+        {
+            var expected = @"
+root = true
+
+[*]
+key = {|Literal:value|}
+";
+
+            var actual = new EditorConfigFile
+            {
+                { "root", "true" },
+                {
+                    "*", new Dictionary<string, string>
+                    {
+                        ["key"] = "{|Literal:value|}",
+                    }
+                },
+                { "*", "key", "{|Literal:value|}" },
+            }.ToString();
+
+            Assert.Equal(expected, actual);
+        }
+
         [DiagnosticAnalyzer(LanguageNames.CSharp)]
         internal class HighlightBracesIfAnalyzerConfigMissingAnalyzer : DiagnosticAnalyzer
         {