Add Array.shift (#19811)

* Add Array.shift for JavaScript targets

* Add Array.shift for JavaScript targets

changelog.md

@@ -37,7 +37,7 @@ becomes an alias for `addr`.
 - Added `initDateTime` in `times` to create a datetime from a weekday, and ISO 8601 week number and week-based year.
 - Added `getIsoWeekAndYear` in `times` to get an ISO week number along with the corresponding ISO week-based year from a datetime.
 - Added `getIsoWeeksInYear` in `times` to return the number of weeks in an ISO week-based year.
-
+- Added [`Array.shift`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift) for JavaScript targets.
 - Added `std/oserrors` for OS error reporting. Added `std/envvars` for environment variables handling.
 - Removed deprecated `oids.oidToString`.
 - Remove define `nimExperimentalAsyncjsThen` for `std/asyncjs.then` and `std/jsfetch`.

lib/js/jscore.nim

@@ -123,3 +123,12 @@ since (1, 5):
       assert [1, 2, 3, 4, 5].copyWithin(0, 3) == @[4, 5, 3, 4, 5]
       assert [1, 2, 3, 4, 5].copyWithin(0, 3, 4) == @[4, 2, 3, 4, 5]
       assert [1, 2, 3, 4, 5].copyWithin(-2, -3, -1) == @[1, 2, 3, 3, 4]
+
+
+since (1, 7):
+  func shift*[T](self: seq[T]): T {.importjs: "#.$1()".} =
+    ## https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift
+    runnableExamples:
+      var arrai = @[1, 2, 3]
+      assert arrai.shift() == 1
+      assert arrai == @[2, 3]