Promise await_list

3 files changed, 22 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 44e1cc9..ea87997 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,4 +10,4 @@
   functions.
 - The `javascript/promise` module was created with the `Promise(value)` type and
   `rescue`, `resolve`, `tap`, `map_try`, `map`, `then_try`, `await{2,6}`,
-  `await_array`, and `then` functions.
+  `await_list`, `await_array`, and `then` functions.
diff --git a/src/gleam/javascript/promise.gleam b/src/gleam/javascript/promise.gleam
index b0841e0..bdd3211 100644
--- a/src/gleam/javascript/promise.gleam
+++ b/src/gleam/javascript/promise.gleam
@@ -90,3 +90,12 @@ pub external fn await6(
 
 pub external fn await_array(Array(Promise(a))) -> Promise(Array(a)) =
   "../../ffi.js" "all_promises"
+
+pub fn await_list(xs: List(Promise(a))) -> Promise(List(a)) {
+  xs
+  |> do_await_list
+  |> map(array.to_list)
+}
+
+pub external fn do_await_list(List(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 4fadbfe..dc70977 100644
--- a/test/gleam/javascript/promise_test.gleam
+++ b/test/gleam/javascript/promise_test.gleam
@@ -140,3 +140,15 @@ pub fn await_array_test() {
   ]))
   |> promise.tap(fn(x) { assert [1, 3, 4, 6, 10, 13] = array.to_list(x) })
 }
+
+pub fn await_list_test() {
+  promise.await_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] = x })
+}