pretty-print values

index.js

@@ -246,7 +246,7 @@ function print_atrule(node, indent_level, css) {
 	let buffer = indent(indent_level) + '@' + node.name
 
 	// @font-face has no prelude
-	if (node.prelude) {
+	if (node.prelude !== null) {
 		buffer += ' ' + substr(node.prelude, css)
 	}
 
@@ -267,7 +267,63 @@ function print_atrule(node, indent_level, css) {
  * @returns {string} A formatted Declaration
  */
 function print_declaration(node, indent_level, css) {
-	return indent(indent_level) + node.property + ': ' + substr(node.value, css) + ';'
+	return indent(indent_level) + node.property.toLowerCase() + ': ' + print_value(node.value, indent_level, css).trim() + ';'
+}
+
+/**
+ * @param {import('css-tree').List} children
+ * @param {number} indent_level
+ * @param {string} css
+ */
+function print_list(children, indent_level, css) {
+	let buffer = ''
+
+	for (let node of children) {
+		if (node !== children.first && node.type !== 'Operator') {
+			buffer += ' '
+		}
+
+		if (node.type === 'Identifier') {
+			// TODO: new CSS keywork NaN should not be lowercased
+			buffer += node.name.toLowerCase()
+		} else if (node.type === 'Function') {
+			buffer += print_function(node, 0, css)
+		} else if (node.type === 'Dimension') {
+			buffer += node.value + node.unit.toLowerCase()
+		} else if (node.type === 'Value') {
+			// Values can be inside var() as fallback
+			// var(--prop, VALUE)
+			buffer += print_value(node, 0, css)
+		} else {
+			buffer += print_unknown(node, 0, css)
+		}
+	}
+	return buffer
+}
+
+/**
+ * @param {import('css-tree').Value | import('css-tree').Raw} node
+ * @param {number} indent_level
+ * @param {string} css
+ */
+function print_value(node, indent_level, css) {
+	if (node.type === 'Raw') {
+		return print_unknown(node, 0, css)
+	}
+
+	return print_list(node.children, 0, css)
+}
+
+/**
+ * @param {import('css-tree').FunctionNode} node
+ * @param {number} indent_level
+ * @param {string} css
+ */
+function print_function(node, indent_level, css) {
+	let buffer = node.name.toLowerCase() + '('
+	buffer += print_list(node.children, 0, css)
+	buffer += ')'
+	return buffer
 }
 
 /**
@@ -316,8 +372,8 @@ export function format(css) {
 	let ast = parse(css, {
 		positions: true,
 		parseAtrulePrelude: false,
-		parseCustomProperty: false,
-		parseValue: false,
+		parseCustomProperty: true,
+		parseValue: true,
 	})
 	return print(ast, 0, css)
 }

test.js

@@ -117,7 +117,7 @@ test('Declarations end with a semicolon (;)', () => {
 	`)
 	let expected = `@font-face {
 	src: url('test');
-	font-family: Test;
+	font-family: test;
 }
 
 css {
@@ -277,7 +277,7 @@ test { a: 1}
 no-layer-2 {
 	color: red;
 	font-size: 1rem;
-	COLOR: green;
+	color: green;
 }
 
 @layer components, deep;
@@ -443,7 +443,7 @@ a.b
 color: green }
 	`)
 	let expected = `a {
-	background: linear-gradient( red, 10% blue, 20% green,100% yellow);
+	background: linear-gradient(red, 10% blue, 20% green, 100% yellow);
 }
 
 a.b .c .d .e .f {
@@ -499,32 +499,54 @@ test('formats selectors with Nth', () => {
 	}
 })
 
-test.skip('formats simple value lists', () => {
+test('formats simple value lists', () => {
 	let actual = format(`
 		a {
 			transition-property: all,opacity;
 			transition: all 100ms ease,opacity 10ms 20ms linear;
+			transition: all   100ms   ease;
+			ANIMATION: COLOR 123MS EASE-OUT;
 			color: rgb(0,0,0);
+			color: HSL(0%,10%,50%);
+			content: 'Test';
+			background-image: url("EXAMPLE.COM");
 		}
 	`)
 	let expected = `a {
 	transition-property: all, opacity;
 	transition: all 100ms ease, opacity 10ms 20ms linear;
+	transition: all 100ms ease;
+	animation: color 123ms ease-out;
 	color: rgb(0, 0, 0);
+	color: hsl(0%, 10%, 50%);
+	content: 'Test';
+	background-image: url("EXAMPLE.COM");
 }`
 	assert.equal(actual, expected)
 })
 
-test.skip('formats nested value lists', () => {
+test('formats nested value lists', () => {
 	let actual = format(`
 		a {
 			background: red,linear-gradient(to bottom,red 10%,green 50%,blue 100%);
-			color: var(--test1,var(--test2,green));
 		}
 	`)
 	let expected = `a {
 	background: red, linear-gradient(to bottom, red 10%, green 50%, blue 100%);
+}`
+	assert.equal(actual, expected)
+})
+
+test('formats nested var()', () => {
+	let actual = format(`
+		a {
+			color: var(--test1,var(--test2,green));
+			color: var(--test3,rgb(0,0,0));
+		}
+	`)
+	let expected = `a {
 	color: var(--test1, var(--test2, green));
+	color: var(--test3, rgb(0, 0, 0));
 }`
 	assert.equal(actual, expected)
 })