Support Node Sass's sass.types.Color(argb) constructor (#398)

Closes #397

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 1.9.0
+
+### Node API
+
+* Add support for `new sass.types.Color(argb)` for creating colors from ARGB hex
+  numbers. This was overlooked when initially adding support for Node Sass's
+  JavaScript API.
+
 ## 1.8.0
 
 ### Command-Line Interface

lib/src/node/value/color.dart

@@ -21,11 +21,32 @@ Object newNodeSassColor(SassColor value) =>
 
 /// The JS constructor for the `sass.types.Color` class.
 final Function colorConstructor = createClass(
-    (_NodeSassColor thisArg, num red, num green, num blue,
-        [num alpha, SassColor dartValue]) {
-  thisArg.dartValue = dartValue ??
-      new SassColor.rgb(
-          _clamp(red), _clamp(green), _clamp(blue), alpha?.clamp(0, 1) ?? 1);
+    (_NodeSassColor thisArg, num redOrArgb,
+        [num green, num blue, num alpha, SassColor dartValue]) {
+  if (dartValue != null) {
+    thisArg.dartValue = dartValue;
+    return;
+  }
+
+  // This has two signatures:
+  //
+  // * `new sass.types.Color(red, green, blue, [alpha])`
+  // * `new sass.types.Color(argb)`
+  //
+  // The latter takes an integer that's interpreted as the hex value 0xAARRGGBB.
+  num red;
+  if (green == null) {
+    var argb = redOrArgb as int;
+    alpha = (argb >> 24) / 0xff;
+    red = (argb >> 16) % 0x100;
+    green = (argb >> 8) % 0x100;
+    blue = argb % 0x100;
+  } else {
+    red = redOrArgb;
+  }
+
+  thisArg.dartValue = new SassColor.rgb(
+      _clamp(red), _clamp(green), _clamp(blue), alpha?.clamp(0, 1) ?? 1);
 }, {
   'getR': (_NodeSassColor thisArg) => thisArg.dartValue.red,
   'getG': (_NodeSassColor thisArg) => thisArg.dartValue.green,

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass
-version: 1.8.0
+version: 1.9.0
 description: A Sass implementation in Dart.
 author: Dart Team <[email protected]>
 homepage: https://github.com/sass/dart-sass

test/node_api/value/color_test.dart

@@ -96,18 +96,29 @@ void main() {
   });
 
   group("from a constructor", () {
-    test("is a color with the given channels", () {
-      var color = callConstructor(sass.types.Color, [11, 12, 13, 0.42]);
-      expect(color, isJSInstanceOf(sass.types.Color));
-      expect(color.getR(), equals(11));
-      expect(color.getG(), equals(12));
-      expect(color.getB(), equals(13));
-      expect(color.getA(), equals(0.42));
+    group("with individual channels", () {
+      test("is a color with the given channels", () {
+        var color = callConstructor(sass.types.Color, [11, 12, 13, 0.42]);
+        expect(color, isJSInstanceOf(sass.types.Color));
+        expect(color.getR(), equals(11));
+        expect(color.getG(), equals(12));
+        expect(color.getB(), equals(13));
+        expect(color.getA(), equals(0.42));
+      });
+
+      test("the alpha channel defaults to 1", () {
+        var color = callConstructor(sass.types.Color, [11, 12, 13]);
+        expect(color.getA(), equals(1.0));
+      });
     });
 
-    test("the alpha channel defaults to 1", () {
-      var color = callConstructor(sass.types.Color, [11, 12, 13]);
-      expect(color.getA(), equals(1.0));
+    test("with an ARGB hex value, is a color with the given channels", () {
+      var color = callConstructor(sass.types.Color, [0x12345678]);
+      expect(color, isJSInstanceOf(sass.types.Color));
+      expect(color.getR(), equals(0x34));
+      expect(color.getG(), equals(0x56));
+      expect(color.getB(), equals(0x78));
+      expect(color.getA(), equals(0x12 / 0xff));
     });
   });
 }