Task<T>

Async operations with cancellation and error handling

Enhanced async/await with cancellation support, progress tracking, and structured error handling

What is Task<T>?

Task provides structured async operations with built-in cancellation, progress tracking, and error handling. Unlike Promises, Tasks can be cancelled and provide detailed error context.

// Task v2: All operations return TaskOutcome<T>
const syncResult = Task().Sync(() => "success")
// Returns: TaskSuccess<string> (extends TaskOutcome<string>)

const _asyncResult = Task().Async(async () => {
  await new Promise((resolve) => setTimeout(resolve, 100))
  return "async success"
})
// Returns: Promise<TaskSuccess<string>>

// Error handling
const errorResult = Task().Sync(() => {
  throw new Error("Something failed")
})
// Returns: TaskFailure<string>

// Transform successful results
const _transformed = Task().Sync(() => 42)
const doubled = _transformed.map((value) => value * 2)

// Chain operations with error handling
const _chained = Task().Sync(() => 5)
const _chainResult = _chained.flatMap((value) => Right(value * 2))

Key Features

Named Tasks

Debug async operations easily with named task contexts

Cancellation

Cancel ongoing operations gracefully when they're no longer needed

Progress Tracking

Monitor long-running operations with progress callbacks

Error Context

Rich error information including task name and stack traces

Common Patterns

Sync and Async Tasks

// Synchronous task
const sync = Task().Sync(
  () => 42,
  (err) => new Error("Failed"),
)

// Asynchronous task
const async = Task().Async(
  async () => await fetchData(),
  async (err) => new Error("Fetch error"),
)

Error Handling with Context

try {
  await Task({ name: "DataProcessor" }).Async(() => {
    throw new Error("Processing failed")
  })
} catch (error) {
  console.log(error.taskInfo.name) // "DataProcessor"
}

Converting Promises

const getUser = Task.fromPromise(fetchAPI, { name: "UserFetch" })

When to Use Task

✓

Long-running async operations that might be cancelled

File uploads, downloads, expensive computations

✓

Operations that need progress tracking

Batch processing, migrations, data imports

✓

When you need better error context than Promises provide

Complex workflows, debugging production issues