[.NET] More robust ndjson handling for Spec/UnitTests

Author: obligaron

dotnet/Gherkin.Specs/AstBuildingTests.cs

@@ -8,12 +8,11 @@ namespace Gherkin.Specs;
 public class AstBuildingTests : EventTestBase
 {
     [Theory, MemberData(nameof(TestFileProvider.GetValidTestFiles), MemberType = typeof(TestFileProvider))]
-    public void TestSuccessfulAstBuilding(string testFeatureFile)
+    public async Task TestSuccessfulAstBuilding(string testFeatureFile)
     {
         var testFile = GetFullPathToTestFeatureFile(testFeatureFile, "good", ".ast.ndjson");
-        var expectedAstContent = GetExpectedContent(testFile.ExpectedFileFullPath);
 
-        var expectedGherkinDocumentEvent = NDJsonParser.Deserialize<Envelope>(expectedAstContent);
+        var expectedGherkinDocumentEvent = await NDJsonParser.DeserializeAsync<Envelope>(testFile.ExpectedFileFullPath);
 
         var raisedEvents = ProcessGherkinEvents(testFile.FullPath, false, true, false);
 
@@ -22,12 +21,11 @@ public void TestSuccessfulAstBuilding(string testFeatureFile)
     }
 
     [Theory, MemberData(nameof(TestFileProvider.GetInvalidTestFiles), MemberType = typeof(TestFileProvider))]
-    public void TestFailedAstBuilding(string testFeatureFile)
+    public async Task TestFailedAstBuilding(string testFeatureFile)
     {
         var testFile = GetFullPathToTestFeatureFile(testFeatureFile, "bad", ".errors.ndjson");
-        var expectedAstContent = GetExpectedContent(testFile.ExpectedFileFullPath);
 
-        var expectedGherkinDocumentEvent = NDJsonParser.Deserialize<Envelope>(expectedAstContent);
+        var expectedGherkinDocumentEvent = await NDJsonParser.DeserializeAsync<Envelope>(testFile.ExpectedFileFullPath);
 
         var raisedEvents = ProcessGherkinEvents(testFile.FullPath, false, true, false);
 

dotnet/Gherkin.Specs/DependencyValidationTests.cs

@@ -71,9 +71,4 @@ protected List<Envelope> ProcessGherkinEvents(string fullPathToTestFeatureFile,
 
         return raisedEvents;
     }
-
-    protected string GetExpectedContent(string expectedAstFile)
-    {
-        return File.ReadAllText(expectedAstFile, Encoding.UTF8);
-    }
 }

dotnet/Gherkin.Specs/EventTestBase.cs

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFrameworks>net9.0;net8.0</TargetFrameworks>
@@ -19,7 +19,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Text.Json" Version="8.0.5" />
+    <PackageReference Include="System.Text.Json" Version="9.0.5" />
   </ItemGroup>
 
   <ItemGroup>

dotnet/Gherkin.Specs/Gherkin.Specs.csproj

@@ -1,26 +1,25 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
 
-
 namespace Gherkin.Specs.Helper;
 
 public class NDJsonParser
 {
-    public static List<T> Deserialize<T>(string ndjson)
+    static readonly JsonSerializerOptions s_SerializerOptions = new(JsonSerializerDefaults.Web)
     {
-        var lines = ndjson.Split(new char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
+        Converters =
+        {
+            new JsonStringEnumConverter(JsonNamingPolicy.CamelCase)
+        }
+    };
 
+    public static async Task<List<T>> DeserializeAsync<T>(string expectedFile)
+    {
         var result = new List<T>();
+        using var contentStream = File.OpenRead(expectedFile);
 
-        foreach (var line in lines)
+        await foreach (var deserializedObject in JsonSerializer.DeserializeAsyncEnumerable<T>(contentStream, true, s_SerializerOptions))
         {
-            var deserializedObject = JsonSerializer.Deserialize<T>(line, new JsonSerializerOptions(JsonSerializerDefaults.Web)
-            {
-                Converters =
-                {
-                    new JsonStringEnumConverter(JsonNamingPolicy.CamelCase)
-                }
-            });
             result.Add(deserializedObject);
         }
 

dotnet/Gherkin.Specs/Helper/NDJsonParser.cs

@@ -8,13 +8,11 @@ namespace Gherkin.Specs;
 public class PicklesTests : EventTestBase
 {
     [Theory, MemberData(nameof(TestFileProvider.GetValidTestFiles), MemberType = typeof(TestFileProvider))]
-    public void TestPickleCompilation(string testFeatureFile)
+    public async Task TestPickleCompilation(string testFeatureFile)
     {
         var testFile = GetFullPathToTestFeatureFile(testFeatureFile, "good", ".pickles.ndjson");
 
-        var expectedContent = GetExpectedContent(testFile.ExpectedFileFullPath);
-
-        var expectedEvents = NDJsonParser.Deserialize<Envelope>(expectedContent);
+        var expectedEvents = await NDJsonParser.DeserializeAsync<Envelope>(testFile.ExpectedFileFullPath);
 
         var raisedEvents = ProcessGherkinEvents(testFile.FullPath, false, false, true);
 

dotnet/Gherkin.Specs/PicklesTests.cs

@@ -8,13 +8,11 @@ namespace Gherkin.Specs;
 public class SourceTests : EventTestBase
 {
     [Theory, MemberData(nameof(TestFileProvider.GetValidTestFiles), MemberType = typeof(TestFileProvider))]
-    public void TestSourceMessage(string testFeatureFile)
+    public async Task TestSourceMessage(string testFeatureFile)
     {
         var testFile = GetFullPathToTestFeatureFile(testFeatureFile, "good", ".source.ndjson");
 
-        var expectedAstContent = GetExpectedContent(testFile.ExpectedFileFullPath);
-
-        var expectedGherkinDocumentEvent = NDJsonParser.Deserialize<Envelope>(expectedAstContent);
+        var expectedGherkinDocumentEvent = await NDJsonParser.DeserializeAsync<Envelope>(testFile.ExpectedFileFullPath);
 
         var raisedEvents = ProcessGherkinEvents(testFile.FullPath, true, false, false);
 

dotnet/Gherkin.Specs/SourceTests.cs

@@ -7,7 +7,7 @@ public static string GenerateTokens(string featureFilePath)
         var tokenFormatterBuilder = new TokenFormatterBuilder();
         var parser = new Parser<object>(tokenFormatterBuilder);
 
-        using (var stream = new FileStream(featureFilePath, FileMode.Open))
+        using (var stream = File.OpenRead(featureFilePath))
         {
             using (var reader = new StreamReader(stream))
             {