pSettle() returns an object for an object.

src/utils.js

@@ -4,7 +4,6 @@ import has from 'lodash.has'
 import humanFormat from 'human-format'
 import isArray from 'lodash.isarray'
 import isString from 'lodash.isstring'
-import mapToArray from 'lodash.map'
 import multiKeyHashInt from 'multikey-hash'
 import xml2js from 'xml2js'
 import {promisify} from 'bluebird'
@@ -107,31 +106,45 @@ export function pFinally (cb) {
   )
 }
 
-// Given an array which contains promises return a promise that is
-// fulfilled when all the items in the array are either fulfilled or
-// rejected.
+// Given a collection (array or object) which contains promises,
+// return a promise that is fulfilled when all the items in the
+// collection are either fulfilled or rejected.
+//
+// This promise will be fulfilled with a collection (of the same type,
+// array or object) containing promise inspections.
 export function pSettle (promises) {
-  return Promise.all(mapToArray(
-    promises,
-    promise => Promise.resolve(promise).then(
-      value => ({
-        isFulfilled: () => true,
-        isRejected: () => false,
-        value: () => value,
-        reason: () => {
-          throw new Error('no reason, the promise has been fulfilled')
+  let mainPromise = Promise.resolve()
+
+  const results = 'length' in promises
+    ? new Array(promises.length)
+    : {}
+
+  forEach(promises, (promise, key) => {
+    mainPromise = mainPromise.then(() => promise).then(
+      value => {
+        results[key] = {
+          isFulfilled: () => true,
+          isRejected: () => false,
+          value: () => value,
+          reason: () => {
+            throw new Error('no reason, the promise has been fulfilled')
+          }
         }
-      }),
-      reason => ({
-        isFulfilled: () => false,
-        isRejected: () => true,
-        value: () => {
-          throw new Error('no value, the promise has been rejected')
-        },
-        reason: () => reason
-      })
+      },
+      reason => {
+        results[key] = {
+          isFulfilled: () => false,
+          isRejected: () => true,
+          value: () => {
+            throw new Error('no value, the promise has been rejected')
+          },
+          reason: () => reason
+        }
+      }
     )
-  ))
+  })
+
+  return mainPromise.then(() => results)
 }
 
 // -------------------------------------------------------------------

src/utils.spec.js

@@ -122,38 +122,6 @@ describe('generateToken()', () => {
 
 // -------------------------------------------------------------------
 
-describe('pSettle()', () => {
-  it('makes an array of PromiseInspection', async () => {
-    const [
-      status1,
-      status2,
-      status3
-    ] = await pSettle([
-      Promise.resolve(42),
-      Math.PI,
-      Promise.reject('fatality')
-    ])
-
-    expect(status1.isRejected()).to.equal(false)
-    expect(status2.isRejected()).to.equal(false)
-    expect(status3.isRejected()).to.equal(true)
-
-    expect(status1.isFulfilled()).to.equal(true)
-    expect(status2.isFulfilled()).to.equal(true)
-    expect(status3.isFulfilled()).to.equal(false)
-
-    expect(status1.value()).to.equal(42)
-    expect(status2.value()).to.equal(Math.PI)
-    expect(::status3.value).to.throw()
-
-    expect(::status1.reason).to.throw()
-    expect(::status2.reason).to.throw()
-    expect(status3.reason()).to.equal('fatality')
-  })
-})
-
-// -------------------------------------------------------------------
-
 describe('parseSize()', function () {
   it('parses a human size', function () {
     expect(parseSize('1G')).to.equal(1e9)
@@ -207,25 +175,59 @@ describe('pFinally()', () => {
 // -------------------------------------------------------------------
 
 describe('pSettle()', () => {
-  it('makes an array of PromiseInspection', async () => {
+  it('works with arrays', async () => {
     const [
       status1,
-      status2
+      status2,
+      status3
     ] = await pSettle([
       Promise.resolve(42),
+      Math.PI,
       Promise.reject('fatality')
     ])
 
     expect(status1.isRejected()).to.equal(false)
-    expect(status2.isRejected()).to.equal(true)
+    expect(status2.isRejected()).to.equal(false)
+    expect(status3.isRejected()).to.equal(true)
 
     expect(status1.isFulfilled()).to.equal(true)
-    expect(status2.isFulfilled()).to.equal(false)
+    expect(status2.isFulfilled()).to.equal(true)
+    expect(status3.isFulfilled()).to.equal(false)
 
     expect(status1.value()).to.equal(42)
-    expect(::status2.value).to.throw()
+    expect(status2.value()).to.equal(Math.PI)
+    expect(::status3.value).to.throw()
 
     expect(::status1.reason).to.throw()
-    expect(status2.reason()).to.equal('fatality')
+    expect(::status2.reason).to.throw()
+    expect(status3.reason()).to.equal('fatality')
+  })
+
+  it('works with objects', async () => {
+    const {
+      a: status1,
+      b: status2,
+      c: status3
+    } = await pSettle({
+      a: Promise.resolve(42),
+      b: Math.PI,
+      c: Promise.reject('fatality')
+    })
+
+    expect(status1.isRejected()).to.equal(false)
+    expect(status2.isRejected()).to.equal(false)
+    expect(status3.isRejected()).to.equal(true)
+
+    expect(status1.isFulfilled()).to.equal(true)
+    expect(status2.isFulfilled()).to.equal(true)
+    expect(status3.isFulfilled()).to.equal(false)
+
+    expect(status1.value()).to.equal(42)
+    expect(status2.value()).to.equal(Math.PI)
+    expect(::status3.value).to.throw()
+
+    expect(::status1.reason).to.throw()
+    expect(::status2.reason).to.throw()
+    expect(status3.reason()).to.equal('fatality')
   })
 })