fix: version and test

BREAKING CHANGE: storage migrations

src/lib/localStorage.spec.ts

@@ -11,7 +11,7 @@ global.window = {}
 
 describe('localStorage', function() {
   const migrations: Migrations<any> = {
-    2: (data: any) => data
+    2: (data: any) => ({ ...data, data: 'new version' })
   }
 
   beforeEach(function() {
@@ -43,6 +43,17 @@ describe('localStorage', function() {
       migrateStorage(key, migrations)
       data = JSON.parse(localStorage.getItem(key) as string)
       expect(data.storage.version).to.equal(2)
+      expect(data.data).to.equal('new version')
+    })
+
+    it('should set corrent version', function() {
+      const key = 'key'
+      const localStorage = getLocalStorage()
+
+      localStorage.setItem(key, JSON.stringify('{ storage: { version: null }}'))
+      migrateStorage(key, migrations)
+      let data = JSON.parse(localStorage.getItem(key) as string)
+      expect(data.storage.version).to.equal(2)
     })
 
     it('should not migrate if there is no migrations left', function() {
@@ -54,6 +65,7 @@ describe('localStorage', function() {
       migrateStorage(key, migrations)
       data = JSON.parse(localStorage.getItem(key) as string)
       expect(data.storage.version).to.equal(2)
+
       migrateStorage(key, migrations)
       expect(data.storage.version).to.equal(2)
     })

src/lib/localStorage.ts

@@ -31,18 +31,21 @@ export function migrateStorage<T>(key: string, migrations: Migrations<T>) {
   if (dataString) {
     const data = JSON.parse(dataString as string)
 
-    if (data.storage) {
-      version = parseInt(data.storage.version || 0, 10)
+    if (data.storage && data.storage.version) {
+      version = parseInt(data.storage.version, 10)
     }
+    let nextVersion = version + 1
 
-    version++
-    while (migrations[version]) {
-      const newData = migrations[version](data)
+    while (migrations[nextVersion]) {
+      const newData = migrations[nextVersion](data)
       localStorage.setItem(
         key,
-        JSON.stringify({ ...(newData as Object), storage: { version } })
+        JSON.stringify({
+          ...(newData as Object),
+          storage: { version: nextVersion }
+        })
       )
-      version++
+      nextVersion++
     }
   }
 }