Promise await_array

4 files changed, 24 insertions, 3 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21931e8..44e1cc9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,5 +9,5 @@
   `to_list`, `from_list`, `map`, `fold`, `fold_right`, `get`, and `length`
   functions.
 - The `javascript/promise` module was created with the `Promise(value)` type and
-  `rescue`, `resolve`, `tap`, `map_try`, `map`, `then_try`, `await{2,6}` and
-  `then` functions.
+  `rescue`, `resolve`, `tap`, `map_try`, `map`, `then_try`, `await{2,6}`,
+  `await_array`, and `then` functions.
diff --git a/src/ffi.js b/src/ffi.js
index 07649e9..ded63ae 100644
--- a/src/ffi.js
+++ b/src/ffi.js
@@ -120,5 +120,9 @@ export function set_reference(ref, value) {
 }
 
 export function all_promises(...promises) {
-  return Promise.all(promises);
+  if (promises.length === 1) {
+    return Promise.all(promises[0]);
+  } else {
+    return Promise.all(promises);
+  }
 }
diff --git a/src/gleam/javascript/promise.gleam b/src/gleam/javascript/promise.gleam
index 5e374dd..b0841e0 100644
--- a/src/gleam/javascript/promise.gleam
+++ b/src/gleam/javascript/promise.gleam
@@ -1,4 +1,5 @@
 import gleam/dynamic.{Dynamic}
+import gleam/javascript/array.{Array}
 
 // TODO: docs
 // TODO: labels
@@ -86,3 +87,6 @@ pub external fn await6(
   Promise(f),
 ) -> Promise(#(a, b, c, d, e, f)) =
   "../../ffi.js" "all_promises"
+
+pub external fn await_array(Array(Promise(a))) -> Promise(Array(a)) =
+  "../../ffi.js" "all_promises"
diff --git a/test/gleam/javascript/promise_test.gleam b/test/gleam/javascript/promise_test.gleam
index 942abcc..4fadbfe 100644
--- a/test/gleam/javascript/promise_test.gleam
+++ b/test/gleam/javascript/promise_test.gleam
@@ -1,4 +1,5 @@
 import gleam/javascript/promise.{Promise}
+import gleam/javascript/array
 import gleam/javascript.{ObjectType}
 
 pub fn map_does_not_collapse_nested_promise_test() -> Promise(Promise(Int)) {
@@ -127,3 +128,15 @@ pub fn await6_test() {
   )
   |> promise.tap(fn(x) { assert #(1, 3, 4, 6, 10, 13) = x })
 }
+
+pub fn await_array_test() {
+  promise.await_array(array.from_list([
+    promise.resolve(1),
+    promise.resolve(3),
+    promise.resolve(4),
+    promise.resolve(6),
+    promise.resolve(10),
+    promise.resolve(13),
+  ]))
+  |> promise.tap(fn(x) { assert [1, 3, 4, 6, 10, 13] = array.to_list(x) })
+}