From f5e3a5a6699ebdd82ee6b03714ac9b0b72d585e9 Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@google.com>
Date: Wed, 16 Sep 2020 14:41:23 -0700
Subject: [PATCH] Add support for nested maps to has-key (#1075)

---
 CHANGELOG.md               |  6 ++++++
 lib/src/functions/map.dart | 14 +++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c5c8578d..5448bf0a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,12 @@
 
   [map-get]: https://sass-lang.com/documentation/modules/map#get
 
+* Add support for nested maps in `map.has-key`.
+  For example, `map.has-key((a: (b: (c: d))), a, b, c)` would return true.
+  See [the documentation][map-has-key] for more details.
+
+  [map-has-key]: https://sass-lang.com/documentation/modules/map#has-key
+
 * Add a `map.deep-merge()` function. This works like `map.merge()`, except that
   nested map values are *also* recursively merged. For example:
 
diff --git a/lib/src/functions/map.dart b/lib/src/functions/map.dart
index 1a6bd00d..a93882bc 100644
--- a/lib/src/functions/map.dart
+++ b/lib/src/functions/map.dart
@@ -81,10 +81,18 @@ final _values = _function(
     (arguments) => SassList(
         arguments[0].assertMap("map").contents.values, ListSeparator.comma));
 
-final _hasKey = _function("has-key", r"$map, $key", (arguments) {
+final _hasKey = _function("has-key", r"$map, $key, $keys...", (arguments) {
   var map = arguments[0].assertMap("map");
-  var key = arguments[1];
-  return SassBoolean(map.contents.containsKey(key));
+  var keys = [arguments[1], ...arguments[2].asList];
+  for (var key in keys.take(keys.length - 1)) {
+    var value = map.contents[key];
+    if (value is SassMap) {
+      map = value;
+    } else {
+      return sassFalse;
+    }
+  }
+  return SassBoolean(map.contents.containsKey(keys.last));
 });
 
 /// Merges [map1] and [map2], with values in [map2] taking precedence.