• value: either the initial value, the value the Promise resolved to, or the value the Promise was rejected with. use .state if you need to be able to tell the difference.
• state: one of "pending", "fulfilled" or "rejected"

And the following methods:

• case({fulfilled, rejected, pending}): maps over the result using the provided handlers, or returns undefined if a handler isn’t available for the current promise state.
• then((value: TValue) => TResult1 | PromiseLike<TResult1>, [(rejectReason: any) => any]): chains additional handlers to the provided promise.

Note that the status strings are available as constants: mobxUtils.PENDING, mobxUtils.REJECTED, mobxUtil.FULFILLED

• IThenable<T> The promise which will be observed
• oldPromise IThenable<T> ? The promise which will be observed

Examples

const fetchResult = fromPromise(fetch("http://someurl"))
// combine with when..
when(
  () => fetchResult.state !== "pending",
  () => {
  }
)
// or a mobx-react component..
const myComponent = observer(({ fetchResult }) => {
  switch(fetchResult.state) {
     case "pending": return <div>Loading...</div>
     case "rejected": return <div>Ooops... {fetchResult.value}</div>
     case "fulfilled": return <div>Gotcha: {fetchResult.value}</div>
  }
// or using the case method instead of switch:
  fetchResult.case({
    pending:   () => <div>Loading...</div>,
    rejected:  error => <div>Ooops.. {error}</div>,
    fulfilled: value => <div>Gotcha: {value}</div>,
  }))
// chain additional handler(s) to the resolve/reject:
fetchResult.then(
  (result) =>  doSomeTransformation(result),
  (rejectReason) => console.error('fetchResult was rejected, reason: ' + rejectReason)
).then(
  (transformedResult) => console.log('transformed fetchResult: ' + transformedResult)
)

Returns IPromiseBasedObservable<T>