title: Core. Invalid Task State Error

A2A Node SDK - v0.1.0 / Modules / Core / InvalidTaskStateError

Class: InvalidTaskStateError

Core.InvalidTaskStateError

Error thrown when attempting to transition a task to an invalid state

This error occurs when trying to change a task’s state in a way that violates the task state machine rules (e.g., trying to mark a failed task as completed).

Example

throw new InvalidTaskStateError(
  'Cannot transition from FAILED to COMPLETED'
);

Hierarchy

• A2AError

  ↳ InvalidTaskStateError

Table of contents

Constructors

• constructor

Properties

• code
• data
• message
• name
• stack
• stackTraceLimit

Methods

• captureStackTrace
• prepareStackTrace
• toJSON

Constructors

constructor

• new InvalidTaskStateError(message): InvalidTaskStateError

Creates a new invalid task state error

Parameters

Returns

InvalidTaskStateError

Overrides

A2AError.constructor

Properties

code

• Readonly code: number

Numeric error code (typically negative, see ERROR_CODES)

Inherited from

A2AError.code

data

• Optional Readonly data: Record<string, unknown>

Optional additional context data for the error

Inherited from

A2AError.data

message

• message: string

Inherited from

A2AError.message

name

• name: string

Inherited from

A2AError.name

stack

• Optional stack: string

Inherited from

A2AError.stack

stackTraceLimit

▪ Static stackTraceLimit: number

The Error.stackTraceLimit property specifies the number of stack frames collected by a stack trace (whether generated by new Error().stack or Error.captureStackTrace(obj)).

The default value is 10 but may be set to any valid JavaScript number. Changes will affect any stack trace captured after the value has been changed.

If set to a non-number value, or set to a negative number, stack traces will not capture any frames.

Inherited from

A2AError.stackTraceLimit

Methods

captureStackTrace

▸ captureStackTrace(targetObject, constructorOpt?): void

Creates a .stack property on targetObject, which when accessed returns a string representing the location in the code at which Error.captureStackTrace() was called.

const myObject = {};
Error.captureStackTrace(myObject);
myObject.stack;  // Similar to `new Error().stack`

The first line of the trace will be prefixed with ${myObject.name}: ${myObject.message}.

The optional constructorOpt argument accepts a function. If given, all frames above constructorOpt, including constructorOpt, will be omitted from the generated stack trace.

The constructorOpt argument is useful for hiding implementation details of error generation from the user. For instance:

function a() {
  b();
}
 
function b() {
  c();
}
 
function c() {
  // Create an error without stack trace to avoid calculating the stack trace twice.
  const { stackTraceLimit } = Error;
  Error.stackTraceLimit = 0;
  const error = new Error();
  Error.stackTraceLimit = stackTraceLimit;
 
  // Capture the stack trace above function b
  Error.captureStackTrace(error, b); // Neither function c, nor b is included in the stack trace
  throw error;
}
 
a();

Parameters

Returns

void

Inherited from

A2AError.captureStackTrace

prepareStackTrace

▸ prepareStackTrace(err, stackTraces): any

Parameters

Returns

any

See

https://v8.dev/docs/stack-trace-api#customizing-stack-traces

Inherited from

A2AError.prepareStackTrace

toJSON

▸ toJSON(): Object

Converts the error to a JSON-serializable object

Returns

Object

JSON representation of the error

Inherited from

A2AError.toJSON