Deep copy initial value in store

v2/internal/deepcopy/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Joel
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

v2/internal/deepcopy/deepcopy.go

@@ -0,0 +1,125 @@
+// deepcopy makes deep copies of things. A standard copy will copy the
+// pointers: deep copy copies the values pointed to.  Unexported field
+// values are not copied.
+//
+// Copyright (c)2014-2016, Joel Scoble (github.com/mohae), all rights reserved.
+// License: MIT, for more details check the included LICENSE file.
+package deepcopy
+
+import (
+	"reflect"
+	"time"
+)
+
+// Interface for delegating copy process to type
+type Interface interface {
+	DeepCopy() interface{}
+}
+
+// Iface is an alias to Copy; this exists for backwards compatibility reasons.
+func Iface(iface interface{}) interface{} {
+	return Copy(iface)
+}
+
+// Copy creates a deep copy of whatever is passed to it and returns the copy
+// in an interface{}.  The returned value will need to be asserted to the
+// correct type.
+func Copy(src interface{}) interface{} {
+	if src == nil {
+		return nil
+	}
+
+	// Make the interface a reflect.Value
+	original := reflect.ValueOf(src)
+
+	// Make a copy of the same type as the original.
+	cpy := reflect.New(original.Type()).Elem()
+
+	// Recursively copy the original.
+	copyRecursive(original, cpy)
+
+	// Return the copy as an interface.
+	return cpy.Interface()
+}
+
+// copyRecursive does the actual copying of the interface. It currently has
+// limited support for what it can handle. Add as needed.
+func copyRecursive(original, cpy reflect.Value) {
+	// check for implement deepcopy.Interface
+	if original.CanInterface() {
+		if copier, ok := original.Interface().(Interface); ok {
+			cpy.Set(reflect.ValueOf(copier.DeepCopy()))
+			return
+		}
+	}
+
+	// handle according to original's Kind
+	switch original.Kind() {
+	case reflect.Ptr:
+		// Get the actual value being pointed to.
+		originalValue := original.Elem()
+
+		// if  it isn't valid, return.
+		if !originalValue.IsValid() {
+			return
+		}
+		cpy.Set(reflect.New(originalValue.Type()))
+		copyRecursive(originalValue, cpy.Elem())
+
+	case reflect.Interface:
+		// If this is a nil, don't do anything
+		if original.IsNil() {
+			return
+		}
+		// Get the value for the interface, not the pointer.
+		originalValue := original.Elem()
+
+		// Get the value by calling Elem().
+		copyValue := reflect.New(originalValue.Type()).Elem()
+		copyRecursive(originalValue, copyValue)
+		cpy.Set(copyValue)
+
+	case reflect.Struct:
+		t, ok := original.Interface().(time.Time)
+		if ok {
+			cpy.Set(reflect.ValueOf(t))
+			return
+		}
+		// Go through each field of the struct and copy it.
+		for i := 0; i < original.NumField(); i++ {
+			// The Type's StructField for a given field is checked to see if StructField.PkgPath
+			// is set to determine if the field is exported or not because CanSet() returns false
+			// for settable fields.  I'm not sure why.  -mohae
+			if original.Type().Field(i).PkgPath != "" {
+				continue
+			}
+			copyRecursive(original.Field(i), cpy.Field(i))
+		}
+
+	case reflect.Slice:
+		if original.IsNil() {
+			return
+		}
+		// Make a new slice and copy each element.
+		cpy.Set(reflect.MakeSlice(original.Type(), original.Len(), original.Cap()))
+		for i := 0; i < original.Len(); i++ {
+			copyRecursive(original.Index(i), cpy.Index(i))
+		}
+
+	case reflect.Map:
+		if original.IsNil() {
+			return
+		}
+		cpy.Set(reflect.MakeMap(original.Type()))
+		for _, key := range original.MapKeys() {
+			originalValue := original.MapIndex(key)
+			copyValue := reflect.New(originalValue.Type()).Elem()
+			copyRecursive(originalValue, copyValue)
+			copyKey := Copy(key.Interface())
+			cpy.SetMapIndex(reflect.ValueOf(copyKey), copyValue)
+		}
+
+	default:
+		cpy.Set(original)
+	}
+}

v2/internal/runtime/store.go

@@ -6,9 +6,12 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	golog "log"
 	"os"
 	"reflect"
 	"sync"
+
+	"github.com/wailsapp/wails/v2/internal/deepcopy"
 )
 
 // Options defines the optional data that may be used
@@ -64,12 +67,17 @@ func fatal(err error) {
 // New creates a new store
 func (p *StoreProvider) New(name string, defaultValue interface{}) *Store {
 
-	dataType := reflect.TypeOf(defaultValue)
+	if defaultValue == nil {
+		golog.Fatal("Cannot initialise a store with nil")
+	}
+
+	dataCopy := deepcopy.Copy(defaultValue)
+	dataType := reflect.TypeOf(dataCopy)
 
 	result := Store{
 		name:     name,
 		runtime:  p.runtime,
-		data:     reflect.ValueOf(defaultValue),
+		data:     reflect.ValueOf(dataCopy),
 		dataType: dataType,
 	}
 

v2/internal/runtime/store_test.go

@@ -14,34 +14,6 @@ import (
 	is2 "github.com/matryer/is"
 )
 
-func TestStoreProvider_NewWithNilDefault(t *testing.T) {
-	is := is2.New(t)
-
-	defaultLogger := logger.NewDefaultLogger()
-	testLogger := internallogger.New(defaultLogger)
-	//testLogger.SetLogLevel(logger.TRACE)
-	serviceBus := servicebus.New(testLogger)
-	err := serviceBus.Start()
-	is.NoErr(err)
-	defer serviceBus.Stop()
-
-	testRuntime := New(serviceBus)
-	storeProvider := newStore(testRuntime)
-
-	testStore := storeProvider.New("test", nil)
-	is.True(testStore.Get() == nil)
-
-	// You should be able to write a new value into a
-	// store initialised with nil
-	err = testStore.Set(100)
-	is.NoErr(err)
-
-	// You shouldn't be able to write different types to the
-	// store
-	err = testStore.Set(false)
-	is.True(err != nil)
-}
-
 func TestStoreProvider_NewWithScalarDefault(t *testing.T) {
 	is := is2.New(t)
 
@@ -86,8 +58,9 @@ func TestStoreProvider_NewWithStructDefault(t *testing.T) {
 
 	testStore := storeProvider.New("test", testValue)
 
-	err = testStore.Set(testValue)
-	is.NoErr(err)
+	testStore.Update(func(current *TestValue) *TestValue {
+		return testValue
+	})
 	testStore.resync()
 	value := testStore.Get()
 	is.Equal(value, testValue)
@@ -96,8 +69,9 @@ func TestStoreProvider_NewWithStructDefault(t *testing.T) {
 	testValue = &TestValue{
 		Name: "there",
 	}
-	err = testStore.Set(testValue)
-	is.NoErr(err)
+	testStore.Update(func(current *TestValue) *TestValue {
+		return testValue
+	})
 	testStore.resync()
 	value = testStore.Get()
 	is.Equal(value, testValue)
@@ -154,8 +128,9 @@ func TestStoreProvider_RapidReadWrite(t *testing.T) {
 						wg.Done()
 						return
 					default:
-						err := store.Set(rand.Int())
-						is.NoErr(err)
+						store.Update(func(current int) int {
+							return rand.Int()
+						})
 					}
 				}
 			}(testStore, ctx, writerCount)