v1.0.0

Cocoar.JsEval v1.0.0

JavaScript/TypeScript execution library for .NET, built on Jint.

Highlights

• JavaScript execution via Jint 4.8 (ES2025 support)
• TypeScript 6.0 transpilation with embedded compiler
• Four execution methods — from full-featured (ExecuteAsync) to high-performance (Evaluate with pre-parsed scripts, < 1 µs per call)
• Built-in globals — console, setTimeout/setInterval, fetch(), structuredClone, atob/btoa, performance.now(), TextEncoder/TextDecoder
• Automatic .NET Task → JS Promise interop
• 8 extensible modules — HTTP, Database, SMTP, Template, AngleSharp, Logging, Common, VirtualFileSystem
• Expression Tree helpers — FilterBuilder<T>, enum-as-string comparison, closure-pattern Contains/IN, nested property paths, collection navigation (Any)
• .d.ts generation from C# types for Monaco Editor IntelliSense
• IJsEngine interface for testability and mocking
• Fluent DI registration — services.AddJsEval(b => b.EnableFetch().AddModule<T>())

Quick Start

dotnet add package Cocoar.JsEval.Engine

services.AddJsEval();

var engine = sp.GetRequiredService<IJsEngine>();
await engine.ExecuteAsync("export const x = 2 + 3;");

Expression Helpers

dotnet add package Cocoar.JsEval.Expressions

var filter = new FilterBuilder<TodoView>()
    .Where("IsArchived", false)
    .WhereIf(customerIds.Count > 0, b => b.Contains("Customer.Id", customerIds))
    .WhereAny<ResponsibleView, Guid>("Responsibles", "Id", userId)
    .WhereEnumAsString("Status", "Active")
    .Build();

var results = await session.Query<TodoView>().Where(filter).ToListAsync();

Packages

Package	Description
Cocoar.JsEval	Core interfaces and helpers
Cocoar.JsEval.Engine	JsEngine + fetch() + DI
Cocoar.JsEval.TypeScript	TypeScript 6.0 transpiler
Cocoar.JsEval.TsDefinition	.d.ts generation for IntelliSense
Cocoar.JsEval.Expressions	Expression Tree helpers (FilterBuilder, enum comparison, Contains/IN)
Cocoar.JsEval.Module.Common	Guid, Sleep, Random
Cocoar.JsEval.Module.Http	Fluent HTTP client
Cocoar.JsEval.Module.Database	SQL Server + PostgreSQL
Cocoar.JsEval.Module.Smtp	Email via MailKit
Cocoar.JsEval.Module.Template	Scriban templates
Cocoar.JsEval.Module.AngleSharp	HTML parsing
Cocoar.JsEval.Module.Logging	Microsoft.Extensions.Logging
Cocoar.JsEval.Module.VirtualFileSystem	Zio VFS