This is a .NET test runner for Test262: ECMAScript Test Suite. It includes parsing and downloading logic for the test suite in package Test262Harness and test suite generator functionality via CLI too, Test262Harness.Console
Following projects are utilizing the test suite generation and show how to create NUnit based test suite that is being generated by downloaded snapshot from test262 GitHub repository.
- Jint
- Generates NUnit test suite to ensure compliance, suite can be run in parallel for faster feedback loop
- esprima-dotnet
- Generates NUnit test suite for parsing tests, also has custom console logic to compare allow-list.txt for problematic files and progress getting the to parse properly
- acornima
- Generates NUnit test suite for parsing tests
First you need need to install the required package to your test project, it should look similar to this:
<ItemGroup>
<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
<PackageReference Include="NUnit" Version="4.0.1" />
<PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
<PackageReference Include="Test262Harness" Version="1.0.0" />
</ItemGroup>
Next you will need a configuration, similar to this (also check the configuration format section):
Test262Harness.settings.json example
{
"SuiteGitSha": "28b31c0bf1960878abb36ab8597a0cae224a684d",
"TargetPath": "./Generated",
"Namespace": "My.Tests.Test262",
"ExcludedFeatures": [
"Atomics",
"Temporal"
],
"ExcludedFlags": [
"async"
],
"ExcludedDirectories": [
"annexB",
"intl402"
],
"ExcludedFiles": [
"language/expressions/object/dstr-async-gen-meth-*",
"language/expressions/assignment/fn-name-lhs-cover.js"
]
}
You need to create minimal test file stub to initialize your testing target, example from Jint project.
using System;
using System.IO;
using Esprima;
using Jint.Native;
using Jint.Native.ArrayBuffer;
using Jint.Runtime;
using Jint.Runtime.Descriptors;
using Jint.Runtime.Interop;
using Test262Harness;
namespace Jint.Tests.Test262;
public static partial class State
{
/// <summary>
/// Pre-compiled scripts for faster execution.
/// </summary>
public static readonly Dictionary<string, Script> Sources = new(StringComparer.OrdinalIgnoreCase);
}
/// <summary>
/// Handles initializing testing state.
/// </summary>
public partial class TestHarness
{
private static partial Task InitializeCustomState()
{
foreach (var file in State.HarnessFiles)
{
var source = file.Program;
State.Sources[Path.GetFileName(file.FileName)] = new JavaScriptParser(source, new ParserOptions(file.FileName)).ParseScript();
}
return Task.CompletedTask;
}
}
public abstract partial class Test262Test
{
private Engine BuildTestExecutor(Test262File file)
{
var engine = new Engine(cfg =>
{
var relativePath = Path.GetDirectoryName(file.FileName);
cfg.EnableModules(new Test262ModuleLoader(State.Test262Stream.Options.FileSystem, relativePath));
});
if (file.Flags.Contains("raw"))
{
// nothing should be loaded
return engine;
}
engine.Execute(State.Sources["assert.js"]);
engine.Execute(State.Sources["sta.js"]);
// initialize engine with Test262 expected host defined functions here
// https://github.com/tc39/test262/blob/main/INTERPRETING.md#host-defined-functions
engine.SetValue("print", new ClrFunction(engine, "print", (_, args) => TypeConverter.ToString(args.At(0))));
// and more...
// the cinded files that that are expected
foreach (var include in file.Includes)
{
engine.Execute(State.Sources[include]);
}
return engine;
}
private static void ExecuteTest(Engine engine, Test262File file)
{
if (file.Type == ProgramType.Module)
{
engine.AddModule(file.FileName, builder => builder.AddSource(file.Program));
engine.ImportModule(file.FileName);
}
else
{
engine.Execute(new JavaScriptParser(file.Program, new ParserOptions(file.FileName)).ParseScript());
}
}
private partial bool ShouldThrow(Test262File testCase, bool strict)
{
return testCase.Negative;
}
}
And also the CLI tool for generating the test suite, run this in you test project directory.
dotnet tool add Test262Harness.Console
When everything is installed, you should be able to run:
dotnet tool restore
dotnet test262 generate
List of most important things you can tweak in configuration file:
Key | Default | Description |
---|---|---|
SuiteGitSha | none | The GitHub commit to use when downloading the test suite |
SuiteDirectory | none | Alternatively, you can point to local repository root |
TargetPath | none | Where to generate the file to |
Namespace | Test262Harness.TestSuite | Namespace for the generated source files |
ExcludedFeatures | [] | Any feature you want to ignore |
ExcludedFlags | [] | Any flag you want to ignore |
ExcludedDirectories | [] | Any sub-directory you would like to ignore, for example annexB |
ExcludedFiles | [] | List of specific files you would like to ignore |
Exclusion maps to setting [Ignore]
attribute in test suite.
- The recommended branch is main, any PR should target this branch
- The main branch is automatically built and published on MyGet. Add this feed to your NuGet sources to use it: https://www.myget.org/F/test262harness/api/v3/index.json
- The main branch is occasionally published on NuGet