remove empty value declaration from style tree

package-lock.json

@@ -1180,9 +1180,9 @@
       "dev": true
     },
     "estree-walker": {
-      "version": "0.8.1",
-      "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-0.8.1.tgz",
-      "integrity": "sha512-H6cJORkqvrNziu0KX2hqOMAlA2CiuAxHeGJXSIoKA/KLv229Dw806J3II6mKTm5xiDX1At1EXCfsOQPB+tMB+g==",
+      "version": "0.9.0",
+      "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-0.9.0.tgz",
+      "integrity": "sha512-12U47o7XHUX329+x3FzNVjCx3SHEzMF0nkDv7r/HnBzX/xNTKxajBk6gyygaxrAFtLj39219oMfbtxv4KpaOiA==",
       "dev": true
     },
     "esutils": {

package.json

@@ -69,7 +69,7 @@
     "eslint": "^6.3.0",
     "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-svelte3": "^2.7.3",
-    "estree-walker": "^0.8.1",
+    "estree-walker": "^0.9.0",
     "is-reference": "^1.1.4",
     "jsdom": "^15.1.1",
     "kleur": "^3.0.3",

src/compiler/parse/read/style.ts

@@ -31,7 +31,7 @@ export default function read_style(parser: Parser, start: number, attributes: No
 
 	// tidy up AST
 	walk(ast, {
-		enter: (node: any) => { // `any` because this isn't an ESTree node
+		enter(node: any) { // `any` because this isn't an ESTree node
 			// replace `ref:a` nodes
 			if (node.type === 'Selector') {
 				for (let i = 0; i < node.children.length; i += 1) {
@@ -47,6 +47,10 @@ export default function read_style(parser: Parser, start: number, attributes: No
 				}
 			}
 
+			if (node.type === 'Declaration' && node.value.children.length === 0) {
+				this.remove();
+			}
+
 			if (node.loc) {
 				node.start = node.loc.start.offset;
 				node.end = node.loc.end.offset;

test/css/samples/empty-value/expected.css

@@ -0,0 +1 @@
+.bar.svelte-xyz{color:blue}

test/css/samples/empty-value/input.svelte

@@ -0,0 +1,11 @@
+<div class='foo bar'></div>
+
+<style>
+	.foo {
+		color:;
+	}
+	.bar {
+		font:;
+		color: blue;
+	}
+</style>