## fromPromise

```ts
function fromPromise<GValue>(
  promise: Promise<GValue>,
): IObservable<IFromPromiseObservableNotifications<GValue>>
```

Creates an Observable from a Promise.

The Observable emits values in the form of Notifications:

- `next`: the returned value of the promise
- `complete`: when the promise is fulfilled
- `error`: when the promise is rejected

⚠️ `fromPromise` should be used only if you already have a Promise, else you should prefer to
use [fromPromiseFactory](../from-promise-factory/from-promise-factory.md) which provides an AbortSignal to properly
cancel any pending tasks.

### Diagram

[![](https://mermaid.ink/img/eyJjb2RlIjoic2VxdWVuY2VEaWFncmFtXG5cbnBhcnRpY2lwYW50IGZyb21Qcm9taXNlIGFzIGZyb21Qcm9taXNlKHByb21pc2UpXG5wYXJ0aWNpcGFudCBPVVRcblxuYWx0IGZ1bGZpbGxlZCB3aXRoIDx2YWx1ZT5cbiAgICBmcm9tUHJvbWlzZS0-Pk9VVDogbmV4dDogdmFsdWVcbiAgICBmcm9tUHJvbWlzZS0-Pk9VVDogY29tcGxldGVcbmVsc2UgcmVqZWN0ZWQgd2l0aCA8ZXJyb3I-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)](https://mermaid-js.github.io/mermaid-live-editor/edit/#eyJjb2RlIjoic2VxdWVuY2VEaWFncmFtXG5cbnBhcnRpY2lwYW50IGZyb21Qcm9taXNlIGFzIGZyb21Qcm9taXNlKHByb21pc2UpXG5wYXJ0aWNpcGFudCBPVVRcblxuYWx0IGZ1bGZpbGxlZCB3aXRoIDx2YWx1ZT5cbiAgICBmcm9tUHJvbWlzZS0-Pk9VVDogbmV4dDogdmFsdWVcbiAgICBmcm9tUHJvbWlzZS0-Pk9VVDogY29tcGxldGVcbmVsc2UgcmVqZWN0ZWQgd2l0aCA8ZXJyb3I-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)
### Examples

#### Simple fulfilled Promise

```ts
const subscribe = fromPromise(Promise.resolve('Hello World !'));

subscribe((notification) => {
  console.log(notification.name, ':', notification.value);
})
```

Output:

```text
next: Hello World !
complete
```

#### Simple rejected Promise

```ts
const subscribe = fromPromise(Promise.reject(new Error('Rejected')));

subscribe((notification) => {
  console.log(notification.name, ':', notification.value);
})
```

Output:

```text
error: Error('Rejected')
```