fix: deep clone query when creating routes

fix #1690

Author: yyx990803

Diff for: src/util/query.js

@@ -29,8 +29,7 @@ export function resolveQuery (
     parsedQuery = {}
   }
   for (const key in extraQuery) {
-    const val = extraQuery[key]
-    parsedQuery[key] = Array.isArray(val) ? val.slice() : val
+    parsedQuery[key] = extraQuery[key]
   }
   return parsedQuery
 }

Diff for: src/util/route.js

@@ -12,12 +12,18 @@ export function createRoute (
   router?: VueRouter
 ): Route {
   const stringifyQuery = router && router.options.stringifyQuery
+
+  let query: any = location.query || {}
+  try {
+    query = clone(query)
+  } catch (e) {}
+
   const route: Route = {
     name: location.name || (record && record.name),
     meta: (record && record.meta) || {},
     path: location.path || '/',
     hash: location.hash || '',
-    query: location.query || {},
+    query,
     params: location.params || {},
     fullPath: getFullPath(location, stringifyQuery),
     matched: record ? formatMatch(record) : []
@@ -28,6 +34,20 @@ export function createRoute (
   return Object.freeze(route)
 }
 
+function clone (value) {
+  if (Array.isArray(value)) {
+    return value.map(clone)
+  } else if (value && typeof value === 'object') {
+    const res = {}
+    for (const key in value) {
+      res[key] = clone(value[key])
+    }
+    return res
+  } else {
+    return value
+  }
+}
+
 // the starting route that represents the initial state
 export const START = createRoute(null, {
   path: '/'

Diff for: test/unit/specs/query.spec.js

@@ -9,15 +9,6 @@ describe('Query utils', () => {
         baz: 'qux'
       }))
     })
-
-    it('should make a copy when param value is an array', () => {
-      const arr = ['bar']
-      const query = resolveQuery('', { foo: arr })
-      arr.push('baz')
-      expect(JSON.stringify(query)).toBe(JSON.stringify({
-        foo: ['bar']
-      }))
-    })
   })
 
   describe('stringifyQuery', () => {