lspeasy / client/src / NotificationWaiter

Class: NotificationWaiter<TParams>

Defined in: packages/client/src/notifications/wait.ts:63

Tracks a single wait-for-notification operation and its timeout lifecycle.

Remarks

Created internally by LSPClient.waitForNotification. Use LSPClient.waitForNotification rather than instantiating this class directly.

Use When

You need to await a specific server-to-client notification after triggering a server-side operation — for example, waiting for textDocument/publishDiagnostics after saving a document.

Avoid When

You need to listen for ongoing notifications (not a one-shot wait) — use LSPClient.onNotification for persistent subscriptions instead.

Never

NEVER create a NotificationWaiter without setting a timeout — an indefinite wait will leak the waiter permanently if the notification never arrives (e.g. the server suppresses it for certain file types).

NEVER use NotificationWaiter to wait for notifications that arrive before the waiter is registered. The waiter only sees notifications emitted after start() is called; earlier notifications are silently missed.

Example

// Wait for diagnostics after saving
const diags = await client.waitForNotification(
  'textDocument/publishDiagnostics',
  {
    timeout: 5000,
    filter: (params) => params.uri === 'file:///src/main.ts',
  }
);
console.log(diags.diagnostics);

Type Parameters

Type Parameter	Description
TParams	The notification params type.

Constructors

Constructor

new NotificationWaiter<TParams>(
   method, 
   options, 
   resolve, 
   reject, 
   onCleanup
): NotificationWaiter<TParams>;

Defined in: packages/client/src/notifications/wait.ts:68

Parameters

Parameter	Type
method	string
options	NotificationWaitOptions<TParams>
resolve	(params) => void
reject	(error) => void
onCleanup	() => void

Returns

NotificationWaiter<TParams>

Methods

cleanup()

cleanup(): void;

Defined in: packages/client/src/notifications/wait.ts:131

Clears timeout state and detaches waiter resources.

Returns

void

---

matches()

matches(method, params): boolean;

Defined in: packages/client/src/notifications/wait.ts:100

Returns whether an incoming notification satisfies this waiter.

Parameters

Parameter	Type	Description
method	string	The notification method string of the incoming message.
params	TParams	The notification params to test against the optional filter predicate.

Returns

boolean

true when the method matches and the filter (if any) passes.

---

reject()

reject(error): void;

Defined in: packages/client/src/notifications/wait.ts:123

Rejects the waiter and performs cleanup.

Parameters

Parameter	Type
error	Error

Returns

void

---

resolve()

resolve(params): void;

Defined in: packages/client/src/notifications/wait.ts:115

Resolves the waiter and performs cleanup.

Parameters

Parameter	Type
params	TParams

Returns

void

---

start()

start(): void;

Defined in: packages/client/src/notifications/wait.ts:82

Starts timeout tracking for the wait operation.

Returns

void