Make plugin ignore case while sorting declarations

lib/__tests__/test.js

@@ -11,14 +11,7 @@ test(`Should throw an error if config has error`, () => {
 		order: 'Justice Rains From Above',
 	};
 
-	const pluginRun = postcss([plugin(opts)])
-		.process('', { from: undefined })
-		.then(() => {
-			expect('Plugin should throw an error').toBeFalst();
-		})
-		.catch((err) => {
-			throw err;
-		});
-
-	expect(pluginRun).rejects.toBeTruthy();
+	return expect(postcss([plugin(opts)]).process('', { from: undefined })).rejects.toThrow(
+		'postcss-sorting: order: Should be an array'
+	);
 });

lib/properties-order/__tests__/fixtures/properties-alphabetical-case-insensitive.css

@@ -0,0 +1,6 @@
+a {
+	Border: red;
+	align-content: center;
+	font-family: sans-serif;
+	Display: block;
+}

lib/properties-order/__tests__/fixtures/properties-alphabetical-case-insensitive.expected.css

@@ -0,0 +1,6 @@
+a {
+	align-content: center;
+	Border: red;
+	Display: block;
+	font-family: sans-serif;
+}

lib/properties-order/__tests__/fixtures/properties-have-same-name-4.css

@@ -0,0 +1,27 @@
+div {
+	position: fixed;
+	top: 0;
+	Top: $header-height;
+	A: 0;
+	b: 1;
+	C: 2;
+	d: 3;
+	E: 4;
+	f: 5;
+	G: 6;
+	h: 7;
+}
+
+div {
+	position: fixed;
+	Top: $header-height;
+	top: 0;
+	a: 0;
+	B: 1;
+	c: 2;
+	D: 3;
+	e: 4;
+	F: 5;
+	g: 6;
+	H: 7;
+}

lib/properties-order/__tests__/fixtures/properties-have-same-name-4.expected.css

@@ -0,0 +1,27 @@
+div {
+	position: fixed;
+	top: 0;
+	Top: $header-height;
+	A: 0;
+	b: 1;
+	C: 2;
+	d: 3;
+	E: 4;
+	f: 5;
+	G: 6;
+	h: 7;
+}
+
+div {
+	position: fixed;
+	Top: $header-height;
+	top: 0;
+	a: 0;
+	B: 1;
+	c: 2;
+	D: 3;
+	e: 4;
+	F: 5;
+	g: 6;
+	H: 7;
+}

lib/properties-order/__tests__/fixtures/properties-have-same-name-5.css

@@ -0,0 +1,29 @@
+.header {
+	Padding-bottom: 20px;
+	-webkit-box-pack: justify;
+	-ms-flex-pack: justify;
+	Justify-content: space-between;
+	display: -webkit-box;
+	Display: -ms-flexbox;
+	display: flex;
+	-webkit-box-align: center;
+	-ms-flex-align: center;
+	Align-items: center;
+	-ms-flex-wrap: wrap;
+	flex-wrap: wrap;
+}
+
+.header {
+	-webkit-box-pack: justify;
+	-ms-Flex-pack: justify;
+	justify-content: space-between;
+	Display: -webkit-box;
+	display: -ms-flexbox;
+	Display: flex;
+	-webkit-box-align: center;
+	-ms-Flex-align: center;
+	align-items: center;
+	-ms-flex-wrap: wrap;
+	flex-wrap: wrap;
+	padding-bottom: 20px;
+}

lib/properties-order/__tests__/fixtures/properties-have-same-name-5.expected.css

@@ -0,0 +1,29 @@
+.header {
+	Align-items: center;
+	-webkit-box-align: center;
+	-webkit-box-pack: justify;
+	display: -webkit-box;
+	Display: -ms-flexbox;
+	display: flex;
+	-ms-flex-align: center;
+	-ms-flex-pack: justify;
+	-ms-flex-wrap: wrap;
+	flex-wrap: wrap;
+	Justify-content: space-between;
+	Padding-bottom: 20px;
+}
+
+.header {
+	align-items: center;
+	-webkit-box-align: center;
+	-webkit-box-pack: justify;
+	Display: -webkit-box;
+	display: -ms-flexbox;
+	Display: flex;
+	-ms-Flex-align: center;
+	-ms-Flex-pack: justify;
+	-ms-flex-wrap: wrap;
+	flex-wrap: wrap;
+	justify-content: space-between;
+	padding-bottom: 20px;
+}

lib/properties-order/__tests__/properties-order.js

@@ -91,6 +91,24 @@ test('Should preserve order if properties have same name', () =>
 		__dirname
 	));
 
+test('Should preserve order if properties have same name (case insensitive)', () =>
+	runTest(
+		'properties-have-same-name-4',
+		{
+			'properties-order': ['position', 'z-index'],
+		},
+		__dirname
+	));
+
+test('Should preserve order if properties have same name (case insensitive)', () =>
+	runTest(
+		'properties-have-same-name-5',
+		{
+			'properties-order': 'alphabetical',
+		},
+		__dirname
+	));
+
 test(`Should not remove first comment in the rule if it's not on separate line (properties-order)`, () =>
 	runTest(
 		'first-comment-in-the-rule',
@@ -145,6 +163,16 @@ test('Should sort properties alphabetically', () =>
 		__dirname
 	));
 
+test('Should sort properties alphabetically regardless of case', () => {
+	runTest(
+		'properties-alphabetical-case-insensitive',
+		{
+			'properties-order': 'alphabetical',
+		},
+		__dirname
+	);
+});
+
 test('Should sort shorthand properties before their longhand versions', () =>
 	runTest(
 		'properties-alphabetical-shorthand',

lib/properties-order/sortNodeProperties.js

@@ -25,7 +25,7 @@ module.exports = function sortNodeProperties(node, { order, unspecifiedPropertie
 			isStandardSyntaxProperty(childNode.prop) &&
 			!isCustomProperty(childNode.prop)
 		) {
-			let unprefixedPropName = vendor.unprefixed(childNode.prop);
+			let unprefixedPropName = vendor.unprefixed(childNode.prop).toLowerCase();
 
 			// Hack to allow -moz-osx-font-smoothing to be understood
 			// just like -webkit-font-smoothing