fix: 🐛 treat isActive to case-insensitive

✅ Closes: vuejs#3656

src/components/link.js

@@ -72,10 +72,11 @@ export default {
       ? createRoute(null, normalizeLocation(route.redirectedFrom), null, router)
       : route
 
+    const ignoreCase = current.matched[0].regex.ignoreCase
     classes[exactActiveClass] = isSameRoute(current, compareTarget, this.exactPath)
     classes[activeClass] = this.exact || this.exactPath
       ? classes[exactActiveClass]
-      : isIncludedRoute(current, compareTarget)
+      : isIncludedRoute(current, compareTarget, ignoreCase)
 
     const ariaCurrentValue = classes[exactActiveClass] ? this.ariaCurrentValue : null
 

src/util/route.js

@@ -116,11 +116,15 @@ function isObjectEqual (a = {}, b = {}): boolean {
   })
 }
 
-export function isIncludedRoute (current: Route, target: Route): boolean {
-  return (
-    current.path.replace(trailingSlashRE, '/').indexOf(
-      target.path.replace(trailingSlashRE, '/')
-    ) === 0 &&
+export function isIncludedRoute (current: Route, target: Route, ignoreCase: boolean = false): boolean {
+  let currentPath = current.path.replace(trailingSlashRE, '/')
+  let targetPath = target.path.replace(trailingSlashRE, '/')
+  if (ignoreCase) {
+    currentPath = currentPath.toLowerCase()
+    targetPath = targetPath.toLowerCase()
+  }
+  const index = currentPath.indexOf(targetPath)
+  return (index === 0 &&
     (!target.hash || current.hash === target.hash) &&
     queryIncludes(current.query, target.query)
   )

test/unit/specs/route.spec.js

@@ -149,5 +149,13 @@ describe('Route utils', () => {
       expect(isIncludedRoute(d, e)).toBe(true)
       expect(isIncludedRoute(d, f)).toBe(false)
     })
+
+    it('ignore case', () => {
+      const a = { path: '/about' }
+      const b = { path: '/ABOUT' }
+      expect(isIncludedRoute(a, b)).toBe(false)
+      expect(isIncludedRoute(a, b, false)).toBe(false)
+      expect(isIncludedRoute(a, b, true)).toBe(true)
+    })
   })
 })