Renamed refectStatus + added its usage in mapGenerator + corrected

sleepCancellable test

Author: nicolas-van

src/mapGenerator.mjs

@@ -4,6 +4,7 @@ import asyncWrap from './asyncWrap.mjs'
 import asyncIterableWrap from './asyncIterableWrap.mjs'
 import getQueue from './getQueue.mjs'
 import Queue from './Queue.mjs'
+import reflectStatus from './reflectStatus.mjs'
 
 /**
  * Produces a an async iterator that will return each value or `iterable` after having processed them through
@@ -74,11 +75,7 @@ async function * mapGenerator (iterable, iteratee, queueOrConcurrency = 1, order
   const waitList = new Map()
   const addToWaitList = (identifier, fct) => {
     const p = (async () => {
-      try {
-        return [identifier, 'resolved', await fct()]
-      } catch (e) {
-        return [identifier, 'rejected', e]
-      }
+      return [identifier, await reflectStatus(fct)]
     })()
     assert(!waitList.has('identifier'), 'waitList already contains identifier')
     waitList.set(identifier, p)
@@ -110,12 +107,11 @@ async function * mapGenerator (iterable, iteratee, queueOrConcurrency = 1, order
         const removed = scheduledList.delete(index)
         assert(removed, 'Couldn\'t find index in scheduledList for removal')
 
-        const [state, result] = await iteratee(value, index, iterable)
-          .then((r) => ['resolved', r], (e) => ['rejected', e])
+        const snapshot = await reflectStatus(() => iteratee(value, index, iterable))
 
         scheduledCount -= 1
-        insertInResults(index, value, state, result)
-        if (state === 'rejected') {
+        insertInResults(index, value, snapshot)
+        if (snapshot.status === 'rejected') {
           shouldStop = true
           cancelAllScheduled(ordered ? index : 0)
         }
@@ -142,10 +138,10 @@ async function * mapGenerator (iterable, iteratee, queueOrConcurrency = 1, order
   const fetch = () => {
     fetching = true
     addToWaitList('next', async () => {
-      const [state, result] = await it.next().then((r) => ['resolved', r], (e) => ['rejected', e])
+      const snapshot = await reflectStatus(() => it.next())
       fetching = false
-      if (state === 'resolved') {
-        const { value, done } = result
+      if (snapshot.status === 'fulfilled') {
+        const { value, done } = snapshot.value
         if (!done) {
           lastIndexFetched += 1
           assert(fetchedValue === null, 'fetchedValue should be null')
@@ -159,19 +155,19 @@ async function * mapGenerator (iterable, iteratee, queueOrConcurrency = 1, order
         exhausted = true
         lastIndexFetched += 1
         const index = lastIndexFetched
-        insertInResults(index, undefined, state, result)
+        insertInResults(index, undefined, snapshot)
         cancelAllScheduled(ordered ? index : 0)
       }
     })
   }
 
-  const insertInResults = (index, value, state, result) => {
+  const insertInResults = (index, value, snapshot) => {
     if (ordered) {
       assert(index - lastIndexHandled - 1 >= 0, 'invalid index to insert')
       assert(results[index - lastIndexHandled - 1] === undefined, 'already inserted result')
-      results[index - lastIndexHandled - 1] = { index, value, state, result }
+      results[index - lastIndexHandled - 1] = { index, value, snapshot }
     } else {
-      results.push({ index, value, state, result })
+      results.push({ index, value, snapshot })
     }
   }
 
@@ -181,10 +177,10 @@ async function * mapGenerator (iterable, iteratee, queueOrConcurrency = 1, order
     while (results.length >= 1 && results[0] !== undefined) {
       const result = results.shift()
       lastIndexHandled += 1
-      if (result.state === 'rejected') {
-        throw result.result
+      if (result.snapshot.status === 'rejected') {
+        throw result.snapshot.reason
       } else {
-        yield result.result
+        yield result.snapshot.value
       }
     }
     if (exhausted && lastIndexFetched === lastIndexHandled) {

src/modern-async.mjs

@@ -43,4 +43,4 @@ export { default as timeout } from './timeout.mjs'
 export { default as TimeoutError } from './TimeoutError.mjs'
 export { default as timeoutPrecise } from './timeoutPrecise.mjs'
 export { default as toArray } from './toArray.mjs'
-export { default as snapshot } from './snapshot.mjs'
+export { default as reflectStatus } from './reflectStatus.mjs'

src/snapshot.mjs renamed to src/reflectStatus.mjs

@@ -22,11 +22,11 @@
  * @returns {Promise<any>} A promise that will always be resolved with an object containing
  * a snapshot of the original promise state.
  * @example
- * import { snapshot, map, sleep } from 'modern-async'
+ * import { reflectStatus, map, sleep } from 'modern-async'
  *
  * const array = [1, 2, 3]
  *
- * const result = await map(array, (v) => snapshot(async () => {
+ * const result = await map(array, (v) => reflectStatus(async () => {
  *   await sleep(10) // waits 10ms
  *   if (v % 2 === 0) { // throws error on some values
  *     throw Error("error")
@@ -42,7 +42,7 @@
  * //   { status: 'fulfilled', value: 3 }
  * // ]
  */
-async function snapshot (fct) {
+async function reflectStatus (fct) {
   try {
     const res = await fct()
     return {
@@ -57,4 +57,4 @@ async function snapshot (fct) {
   }
 }
 
-export default snapshot
+export default reflectStatus

src/snapshot.test.mjs renamed to src/reflectStatus.test.mjs

@@ -1,10 +1,10 @@
 
 import { expect, test } from '@jest/globals'
-import snapshot from './snapshot.mjs'
+import reflectStatus from './reflectStatus.mjs'
 import delay from './delay.mjs'
 
-test('snapshot base test', async () => {
-  const res1 = await snapshot(async () => {
+test('reflectStatus base test', async () => {
+  const res1 = await reflectStatus(async () => {
     await delay()
     return 3
   })
@@ -15,8 +15,8 @@ test('snapshot base test', async () => {
   expect(res1.reason).toBeUndefined()
 })
 
-test('snapshot falure', async () => {
-  const res1 = await snapshot(async () => {
+test('reflectStatus falure', async () => {
+  const res1 = await reflectStatus(async () => {
     await delay()
     throw new Error('error')
   })

src/sleepCancellable.test.mjs

@@ -12,31 +12,12 @@ test('sleepCancellable base', async () => {
 })
 
 test('sleepCancellable cancel', async () => {
-  const start = new Date().getTime()
   const [p, cancel] = sleepCancellable(100)
   expect(cancel()).toBe(true)
   try {
     await p
     expect(true).toBe(false)
   } catch (e) {
-    const end = new Date().getTime()
-    expect(end - start).toBeLessThan(50)
-    expect(e).toBeInstanceOf(CancelledError)
-  }
-})
-
-test('sleepCancellable async cancel', async () => {
-  const start = new Date().getTime()
-  const [p, cancel] = sleepCancellable(100)
-  setTimeout(() => {
-    expect(cancel()).toBe(true)
-  }, 10)
-  try {
-    await p
-    expect(true).toBe(false)
-  } catch (e) {
-    const end = new Date().getTime()
-    expect(end - start).toBeLessThan(50)
     expect(e).toBeInstanceOf(CancelledError)
   }
 })