From 6e1a44ae59eaa6d513014bbafdaa26d14ac8107c Mon Sep 17 00:00:00 2001
From: XhmikosR <xhmikosr@gmail.com>
Date: Mon, 25 May 2026 07:47:18 +0300
Subject: [PATCH 1/4] index: make references a const

After 4942da3 this is safe.
---
 src/index.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 9ab10c3..f8abd52 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -21,7 +21,6 @@ export interface Options {
 }
 
 function detective(src: string, options: Options = { url: false }): string[] {
-  let references: string[] = [];
   let root: Root;
 
   try {
@@ -30,6 +29,8 @@ function detective(src: string, options: Options = { url: false }): string[] {
     throw new MalformedCssError();
   }
 
+  const references: string[] = [];
+
   root.walkAtRules((rule) => {
     let file = null;
 

From bdbd381a3245797cc08d43173d16f63af277a0ae Mon Sep 17 00:00:00 2001
From: XhmikosR <xhmikosr@gmail.com>
Date: Mon, 25 May 2026 07:52:57 +0300
Subject: [PATCH 2/4] index: use optional chaining

---
 src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index f8abd52..2b39df8 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -99,7 +99,7 @@ function getUrlContent(urlNode: Func): string {
   const first = urlNode.nodes[0];
 
   // Quoted: url('foo.css') or url("foo.css")
-  if (first && first.type === 'quoted') {
+  if (first?.type === 'quoted') {
     return first.contents;
   }
 

From 6c5c4f5619ddc909127cbaa3f4b3d5beaee27e78 Mon Sep 17 00:00:00 2001
From: XhmikosR <xhmikosr@gmail.com>
Date: Mon, 25 May 2026 07:59:30 +0300
Subject: [PATCH 3/4] index: avoid object literal as default for options

Fixes unicorn/no-object-as-default-parameter. url is optional and only
checked for truthiness, so the empty default is equivalent.
---
 src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 2b39df8..e55f442 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -20,7 +20,7 @@ export interface Options {
   url?: boolean;
 }
 
-function detective(src: string, options: Options = { url: false }): string[] {
+function detective(src: string, options: Options = {}): string[] {
   let root: Root;
 
   try {

From 5af9b0d92b1f67cabe23e01f872d032fd0f6481c Mon Sep 17 00:00:00 2001
From: XhmikosR <xhmikosr@gmail.com>
Date: Mon, 25 May 2026 08:06:22 +0300
Subject: [PATCH 4/4] index: simplify url filtering

Return undefined for absent values instead of false, and cast
filter(Boolean) to string[] instead of using a type predicate.
---
 src/index.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index e55f442..0256422 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -75,7 +75,7 @@ function detective(src: string, options: Options = {}): string[] {
     const files = nodes
       .filter((node) => isUrlNode(node))
       .map((node) => getValueOrUrl(node))
-      .filter((file): file is string => Boolean(file));
+      .filter(Boolean) as string[];
 
     for (const file of files) {
       debug('found %s of %s', 'url() in declaration', file);
@@ -87,12 +87,12 @@ function detective(src: string, options: Options = {}): string[] {
   return references;
 }
 
-function getValueOrUrl(node: ChildNode): string | false {
+function getValueOrUrl(node: ChildNode): string | undefined {
   const ret = isUrlNode(node) ? getUrlContent(node) : getValue(node);
 
   // is-url-superb uses new URL() which doesn't accept protocol-relative URLs;
   // prepend http: so they get correctly identified and filtered out
-  return !isUrl(ret.startsWith('//') ? `http:${ret}` : ret) && ret;
+  return isUrl(ret.startsWith('//') ? `http:${ret}` : ret) ? undefined : ret;
 }
 
 function getUrlContent(urlNode: Func): string {