UnexpectedStateError

@codebolt/mcp

---

Class: UnexpectedStateError

Defined in: packages/mcp/src/mcpServer.ts:124

Error class for unexpected state conditions.

Extends

• FastMCPError

Extended by

• UserError

Constructors

Constructor

new UnexpectedStateError(message: string, extras?: Extras): UnexpectedStateError;

Defined in: packages/mcp/src/mcpServer.ts:134

Creates a new UnexpectedStateError.

Parameters

Parameter	Type	Description
message	string	Error message
extras?	Extras	Additional context for the error

Returns

UnexpectedStateError

Overrides

FastMCPError.constructor

Properties

Property	Modifier	Type	Description	Inherited from	Defined in
extras?	public	Extras	Additional context for the error	-	packages/mcp/src/mcpServer.ts:126
message	public	string	-	FastMCPError.message	node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.es5.d.ts:1077
name	public	string	-	FastMCPError.name	node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.es5.d.ts:1076
stack?	public	string	-	FastMCPError.stack	node_modules/.pnpm/typescript@5.9.3/node_modules/typescript/lib/lib.es5.d.ts:1078
stackTraceLimit	static	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.	FastMCPError.stackTraceLimit	node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/globals.d.ts:68

Methods

captureStackTrace()

static captureStackTrace(targetObject: object, constructorOpt?: Function): void;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/globals.d.ts:52

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

Parameter	Type
targetObject	object
constructorOpt?	Function

Returns

void

Inherited from

FastMCPError.captureStackTrace

---

prepareStackTrace()

static prepareStackTrace(err: Error, stackTraces: CallSite[]): any;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/globals.d.ts:56

Parameters

Parameter	Type
err	Error
stackTraces	CallSite[]

Returns

any

See

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

Inherited from

FastMCPError.prepareStackTrace