🧪 [테스트 개선: cn 유틸리티 함수]

apps/desktop/src/features/workspace/RoleSwitcher.tsx

@@ -43,7 +43,7 @@ export function RoleSwitcher({ roles, activeRole, onRoleChange }: RoleSwitcherPr
   return (
     <div className="flex flex-col gap-4 py-2 sm:flex-row sm:items-center">
       <div className="flex whitespace-nowrap text-sm font-semibold text-slate-200">
-        <Users className="mr-2 size-4 text-cyan-300" />
+        <Users className="mr-2 size-4 text-cyan-300" aria-hidden="true" />
         {t("roleSwitcherTitle")}
       </div>
       <Tabs

apps/desktop/src/features/workspace/SectionRoadmap.tsx

@@ -165,14 +165,14 @@ export function SectionRoadmap({ song, activeRole, onSongUpdate }: SectionRoadma
 
                         {role.setupNote && (
                           <div className="flex items-start gap-2 rounded-md border border-amber-300/20 bg-amber-300/[0.08] p-2 text-xs font-medium text-amber-100">
-                            <Lightbulb className="mt-0.5 size-3.5 shrink-0" />
+                            <Lightbulb className="mt-0.5 size-3.5 shrink-0" aria-hidden="true" />
                             <span className="leading-snug">{role.setupNote}</span>
                           </div>
                         )}
 
                         {role.simplification && (
                           <div className="flex items-start gap-2 rounded-md border border-indigo-300/20 bg-indigo-300/[0.08] p-2 text-xs font-medium text-indigo-100">
-                            <Wand2 className="mt-0.5 size-3.5 shrink-0" />
+                            <Wand2 className="mt-0.5 size-3.5 shrink-0" aria-hidden="true" />
                             <span className="leading-snug">{role.simplification}</span>
                           </div>
                         )}
@@ -181,7 +181,7 @@ export function SectionRoadmap({ song, activeRole, onSongUpdate }: SectionRoadma
                           <div className="mt-2 space-y-1.5">
                             {role.overlapWarnings.map((warning, wIdx) => (
                               <div key={wIdx} className="flex items-start gap-2 rounded-md border border-rose-300/20 bg-rose-300/[0.08] p-2 text-xs font-medium text-rose-100">
-                                <AlertCircle className="mt-0.5 size-3.5 shrink-0" />
+                                <AlertCircle className="mt-0.5 size-3.5 shrink-0" aria-hidden="true" />
                                 <span className="leading-snug">{warning}</span>
                               </div>
                             ))}

apps/desktop/src/features/workspace/Workspace.tsx

@@ -222,7 +222,7 @@ export function Workspace({ song, sourceBootstrap = null, onSongUpdate }: Worksp
               onClick={handleExportCueSheet}
                 className="min-h-10 border-cyan-300/30 bg-cyan-300/10 font-semibold text-cyan-50 shadow-[0_10px_30px_rgba(34,211,238,0.16)] hover:bg-cyan-300/20 hover:text-white"
             >
-                <Download className="mr-2 size-4 text-cyan-200" />
+                <Download className="mr-2 size-4 text-cyan-200" aria-hidden="true" />
               Export Cue Sheet (CSV)
             </Button>
             <Button
@@ -231,7 +231,7 @@ export function Workspace({ song, sourceBootstrap = null, onSongUpdate }: Worksp
               onClick={handleExportChart}
                 className="min-h-10 border-white/10 bg-white/5 font-semibold text-slate-100 shadow-sm hover:bg-white/10 hover:text-white"
             >
-                <Download className="mr-2 size-4 text-slate-300" />
+                <Download className="mr-2 size-4 text-slate-300" aria-hidden="true" />
               Export Chart (JSON)
             </Button>
             <Button
@@ -240,7 +240,7 @@ export function Workspace({ song, sourceBootstrap = null, onSongUpdate }: Worksp
               onClick={handleExportHandoff}
               className="min-h-10 border-teal-300/25 bg-teal-300/10 font-semibold text-teal-50 shadow-sm hover:bg-teal-300/20 hover:text-white"
             >
-              <Download className="mr-2 size-4 text-teal-200" />
+              <Download className="mr-2 size-4 text-teal-200" aria-hidden="true" />
               Export Handoff (JSON)
             </Button>
           </div>

apps/desktop/src/lib/utils.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it } from "vitest";
+import { cn } from "./utils";
+
+describe("cn", () => {
+  it("merges basic classes", () => {
+    expect(cn("a", "b")).toBe("a b");
+  });
+
+  it("handles conditional classes", () => {
+    const isTrue = true;
+    const isFalse = false;
+    expect(cn("a", isTrue && "b", isFalse && "c")).toBe("a b");
+  });
+
+  it("resolves tailwind conflicts", () => {
+    expect(cn("bg-red-500", "bg-blue-500")).toBe("bg-blue-500");
+    expect(cn("px-2 py-1", "p-4")).toBe("p-4");
+  });
+
+  it("handles arrays and objects", () => {
+    expect(cn(["a", "b"], { c: true, d: false })).toBe("a b c");
+  });
+
+  it("handles falsy inputs", () => {
+    expect(cn("a", null, undefined, "", 0, false)).toBe("a");
+  });
+});