fix: collect of used variables for changed selector (#1217)

Author: vsn4ik

packages/purgecss/__tests__/css-variables.test.ts

@@ -27,4 +27,7 @@ describe("purge unused css variables", () => {
     expect(purgedCSS.includes("--color-first:")).toBe(true);
     expect(purgedCSS.includes("--wrong-order:")).toBe(true);
   });
+  it("keeps '--outline-color'", () => {
+    expect(purgedCSS.includes("--outline-color:")).toBe(true);
+  });
 });

packages/purgecss/__tests__/test_examples/css-variables/variables.css

@@ -7,6 +7,7 @@
   --used-color: rebeccapurple;
   --accent-color: orange;
   --wrong-order: yellow;
+  --outline-color: coral;
   --random: var(--not-existing);
 }
 
@@ -19,6 +20,10 @@
   border-color: var(--border-color);
 }
 
+.button, .unused-class {
+  outline-color: var(--outline-color);
+}
+
 .button:focus {
   background-color: var(--accent-color);
   color: var(--primary-color);

packages/purgecss/src/index.ts

@@ -525,7 +525,6 @@ class PurgeCSS {
       return;
     }
 
-    let keepSelector = true;
     const selectorsRemovedFromRule: string[] = [];
 
     // selector transformer, walk over the list of the parsed selectors twice.
@@ -540,7 +539,7 @@ class PurgeCSS {
           return;
         }
 
-        keepSelector = this.shouldKeepSelector(selector, selectors);
+        const keepSelector = this.shouldKeepSelector(selector, selectors);
 
         if (!keepSelector) {
           if (this.options.rejected) {
@@ -575,7 +574,7 @@ class PurgeCSS {
     }).processSync(node.selector);
 
     // declarations
-    if (keepSelector && typeof node.nodes !== "undefined") {
+    if (node.selector && typeof node.nodes !== "undefined") {
       for (const childNode of node.nodes) {
         if (childNode.type !== "decl") continue;
         this.collectDeclarationsData(childNode);