From 72ee5e09a6319ece35323ba145977e6d17047663 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Sun, 15 Dec 2019 01:43:18 +0300
Subject: [PATCH 1/9] Add type signature for Promise.allSettled()

---
 lib/core.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/core.js b/lib/core.js
index 2b576f7996e..feee746a147 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -688,12 +688,16 @@ declare class Promise<+R> {
     static resolve<T>(object: Promise<T> | T): Promise<T>;
     static reject<T>(error: any): Promise<T>;
     static all<T: Iterable<mixed>>(promises: T): Promise<$TupleMap<T, typeof $await>>;
+    static allSettled<T: Iterable<mixed>>(promises: T): Promise<$TupleMap<T, typeof $settlement>>;
     static race<T, Elem: Promise<T> | T>(promises: Iterable<Elem>): Promise<T>;
 }
 
 // we use this signature when typing await expressions
 declare function $await<T>(p: Promise<T> | T): T;
 
+declare function $settlement<T>(p: Promise<T> | T): SettlementResult<T>;
+declare type SettlementResult<T> = { status: 'fulfilled', value: T } | { status: 'rejected', reason: any };
+
 /* Binary data */
 
 declare class ArrayBuffer {

From cb3c239fc6afc556248baa420254ee078eaa0939 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Sat, 7 Mar 2020 03:53:24 +0300
Subject: [PATCH 2/9] Make object types in SettlementResult exact

---
 lib/core.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/core.js b/lib/core.js
index feee746a147..e8725f56e77 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -696,7 +696,7 @@ declare class Promise<+R> {
 declare function $await<T>(p: Promise<T> | T): T;
 
 declare function $settlement<T>(p: Promise<T> | T): SettlementResult<T>;
-declare type SettlementResult<T> = { status: 'fulfilled', value: T } | { status: 'rejected', reason: any };
+declare type SettlementResult<T> = {| status: 'fulfilled', value: T |} | {| status: 'rejected', reason: any |};
 
 /* Binary data */
 

From 56350b3195c3d0d43ef3e36909a5e2da45ae447e Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Sat, 7 Mar 2020 04:08:40 +0300
Subject: [PATCH 3/9] Replace 'any' in SettlementResult by 'mixed'

---
 lib/core.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/core.js b/lib/core.js
index e8725f56e77..a72689c87de 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -696,7 +696,7 @@ declare class Promise<+R> {
 declare function $await<T>(p: Promise<T> | T): T;
 
 declare function $settlement<T>(p: Promise<T> | T): SettlementResult<T>;
-declare type SettlementResult<T> = {| status: 'fulfilled', value: T |} | {| status: 'rejected', reason: any |};
+declare type SettlementResult<T> = {| status: 'fulfilled', value: T |} | {| status: 'rejected', reason: mixed |};
 
 /* Binary data */
 

From dfc97b690a692ac938bac30fe346929999d72106 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Sat, 7 Mar 2020 04:25:35 +0300
Subject: [PATCH 4/9] Make SettlementResult covariant

---
 lib/core.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/core.js b/lib/core.js
index a72689c87de..a6270a7c71a 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -696,7 +696,7 @@ declare class Promise<+R> {
 declare function $await<T>(p: Promise<T> | T): T;
 
 declare function $settlement<T>(p: Promise<T> | T): SettlementResult<T>;
-declare type SettlementResult<T> = {| status: 'fulfilled', value: T |} | {| status: 'rejected', reason: mixed |};
+declare type SettlementResult<+T> = {| status: 'fulfilled', +value: T |} | {| status: 'rejected', reason: mixed |};
 
 /* Binary data */
 

From 91e74a0c5419e81eb9f6fd01f738850e5cb43b39 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Tue, 10 Mar 2020 04:23:43 +0300
Subject: [PATCH 5/9] Add test suite for good cases

---
 tests/core_tests/allSettled.js | 55 ++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 tests/core_tests/allSettled.js

diff --git a/tests/core_tests/allSettled.js b/tests/core_tests/allSettled.js
new file mode 100644
index 00000000000..1d64573a3dd
--- /dev/null
+++ b/tests/core_tests/allSettled.js
@@ -0,0 +1,55 @@
+// @flow
+
+function* generator(): Iterable<Promise<number>> {
+    while (true) {
+        yield Promise.resolve(1);
+    }
+}
+
+let tests = [
+    // good cases
+    function() {
+        let p1 : Promise<[]> = Promise.allSettled([]);
+        let p2 : Promise<[
+            SettlementResult<number>,
+            SettlementResult<string>,
+            SettlementResult<boolean>,
+        ]> = Promise.allSettled([1, '', false]);
+        let p3 : Promise<[
+            SettlementResult<number>,
+            SettlementResult<string>,
+            SettlementResult<boolean>,
+        ]> = Promise.allSettled([
+            Promise.resolve(1),
+            Promise.resolve(''),
+            Promise.resolve(false),
+        ]);
+        let p4 : Promise<[
+            SettlementResult<number>,
+            SettlementResult<number>,
+        ]> = Promise.allSettled([
+            1,
+            Promise.resolve(1),
+        ]);
+        let p5 : Promise<$ReadOnlyArray<SettlementResult<number>>> = Promise.allSettled(generator());
+
+        p5.then((results): Array<number> => {
+            return results.map(result => {
+                if (result.status === 'fulfilled') {
+                    return result.value;
+                } else {
+                    return -1;
+                }
+            });
+        });
+        p5.then((results): Array<number> => {
+            return results.map(result => {
+                if (result.status === 'rejected') {
+                    return -1;
+                } else {
+                    return result.value
+                }
+            });
+        });
+    },
+];
\ No newline at end of file

From d929c014ae182419f3e27b33f56e1b19d3f376c8 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Tue, 10 Mar 2020 06:07:10 +0300
Subject: [PATCH 6/9] Add test suite for cases with wrong args

---
 tests/core_tests/allSettled.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tests/core_tests/allSettled.js b/tests/core_tests/allSettled.js
index 1d64573a3dd..6f95af782e3 100644
--- a/tests/core_tests/allSettled.js
+++ b/tests/core_tests/allSettled.js
@@ -52,4 +52,10 @@ let tests = [
             });
         });
     },
+    // wrong arguments
+    function() {
+        let p1 = Promise.allSettled();
+        let p2 = Promise.allSettled(1);
+        let p3 = Promise.allSettled(Promise.resolve(1));
+    },
 ];
\ No newline at end of file

From 0c4a12e7f8c8a1399d3f0de2707697bc29030bb2 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Tue, 10 Mar 2020 06:10:47 +0300
Subject: [PATCH 7/9] Add test suite for cases with wrong result types

---
 tests/core_tests/allSettled.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/core_tests/allSettled.js b/tests/core_tests/allSettled.js
index 6f95af782e3..4542b67e13a 100644
--- a/tests/core_tests/allSettled.js
+++ b/tests/core_tests/allSettled.js
@@ -58,4 +58,14 @@ let tests = [
         let p2 = Promise.allSettled(1);
         let p3 = Promise.allSettled(Promise.resolve(1));
     },
+    // wrong result type
+    function() {
+        let p1 : Promise<void> = Promise.allSettled([]);
+        let p2 : Promise<[number, string, boolean]> = Promise.allSettled([1, '', false]);
+        let p3 : Promise<[number, string, boolean]> = Promise.allSettled([
+            Promise.resolve(1),
+            Promise.resolve(''),
+            Promise.resolve(false),
+        ]);
+    },
 ];
\ No newline at end of file

From aa3d4304aa8138f3a4567eba48fdd768112cdd29 Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Tue, 10 Mar 2020 06:22:31 +0300
Subject: [PATCH 8/9] Add test suite for cases with wrong result handling

---
 tests/core_tests/allSettled.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tests/core_tests/allSettled.js b/tests/core_tests/allSettled.js
index 4542b67e13a..413bc7bc531 100644
--- a/tests/core_tests/allSettled.js
+++ b/tests/core_tests/allSettled.js
@@ -68,4 +68,16 @@ let tests = [
             Promise.resolve(false),
         ]);
     },
+    // wrong result handling
+    function() {
+        let p1 = Promise.allSettled(generator());
+
+        p1.then((results): Array<number> => {
+            return results.map(result => result);
+        });
+
+        p1.then((results): Array<number> => {
+            return results.map(result => result.value);
+        });
+    },
 ];
\ No newline at end of file

From f792f2115dbd17f986469f320454e3d5231b9b5a Mon Sep 17 00:00:00 2001
From: shau-kote <>
Date: Tue, 10 Mar 2020 06:37:34 +0300
Subject: [PATCH 9/9] Add trailing newline

---
 tests/core_tests/allSettled.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/core_tests/allSettled.js b/tests/core_tests/allSettled.js
index 413bc7bc531..fa3f8b6b3da 100644
--- a/tests/core_tests/allSettled.js
+++ b/tests/core_tests/allSettled.js
@@ -80,4 +80,4 @@ let tests = [
             return results.map(result => result.value);
         });
     },
-];
\ No newline at end of file
+];