Fixes and improved test coverage

util/wrapper/wrapper.go

@@ -2,6 +2,7 @@ package wrapper
 
 import (
 	"context"
+	"reflect"
 	"strings"
 	"time"
 
@@ -229,7 +230,7 @@ func AuthHandler(fn func() auth.Auth) server.HandlerWrapper {
 }
 
 type cacheWrapper struct {
-	cache func() *client.Cache
+	cacheFn func() *client.Cache
 	client.Client
 }
 
@@ -243,7 +244,7 @@ func (c *cacheWrapper) Call(ctx context.Context, req client.Request, rsp interfa
 	}
 
 	// if the client doesn't have a cacbe setup don't continue
-	cache := c.cache()
+	cache := c.cacheFn()
 	if cache == nil {
 		return c.Client.Call(ctx, req, rsp, opts...)
 	}
@@ -253,9 +254,15 @@ func (c *cacheWrapper) Call(ctx context.Context, req client.Request, rsp interfa
 		return c.Client.Call(ctx, req, rsp, opts...)
 	}
 
-	// check to see if there is a response
+	// if the response is nil don't call the cache since we can't assign the response
+	if rsp == nil {
+		return c.Client.Call(ctx, req, rsp, opts...)
+	}
+
+	// check to see if there is a response cached, if there is assign it
 	if r, ok := cache.Get(ctx, &req); ok {
-		rsp = r
+		val := reflect.ValueOf(rsp).Elem()
+		val.Set(reflect.ValueOf(r).Elem())
 		return nil
 	}
 

util/wrapper/wrapper_test.go

@@ -2,6 +2,7 @@ package wrapper
 
 import (
 	"context"
+	"reflect"
 	"testing"
 	"time"
 
@@ -56,25 +57,33 @@ func TestWrapper(t *testing.T) {
 type testClient struct {
 	callCount int
 	callRsp   interface{}
-	cache     *client.Cache
 	client.Client
 }
 
 func (c *testClient) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
 	c.callCount++
-	rsp = c.callRsp
+
+	if c.callRsp != nil {
+		val := reflect.ValueOf(rsp).Elem()
+		val.Set(reflect.ValueOf(c.callRsp).Elem())
+	}
+
 	return nil
 }
 
-func (c *testClient) Options() client.Options {
-	return client.Options{Cache: c.cache}
+type testRsp struct {
+	value string
 }
+
 func TestCacheWrapper(t *testing.T) {
 	req := client.NewRequest("go.micro.service.foo", "Foo.Bar", nil)
 
 	t.Run("NilCache", func(t *testing.T) {
 		cli := new(testClient)
-		w := CacheClient(cli)
+
+		w := CacheClient(func() *client.Cache {
+			return nil
+		}, cli)
 
 		// perfroming two requests should increment the call count by two indicating the cache wasn't
 		// used even though the WithCache option was passed.
@@ -88,7 +97,11 @@ func TestCacheWrapper(t *testing.T) {
 
 	t.Run("OptionNotSet", func(t *testing.T) {
 		cli := new(testClient)
-		w := CacheClient(cli)
+		cache := client.NewCache()
+
+		w := CacheClient(func() *client.Cache {
+			return cache
+		}, cli)
 
 		// perfroming two requests should increment the call count by two since we didn't pass the WithCache
 		// option to Call.
@@ -101,13 +114,21 @@ func TestCacheWrapper(t *testing.T) {
 	})
 
 	t.Run("OptionSet", func(t *testing.T) {
-		cli := &testClient{callRsp: "foobar", cache: client.NewCache()}
-		w := CacheClient(cli)
+		val := "foo"
+		cli := &testClient{callRsp: &testRsp{value: val}}
+		cache := client.NewCache()
+
+		w := CacheClient(func() *client.Cache {
+			return cache
+		}, cli)
 
 		// perfroming two requests should increment the call count by once since the second request should
-		// have used the cache
-		err1 := w.Call(context.TODO(), req, nil, client.WithCache(time.Minute))
-		err2 := w.Call(context.TODO(), req, nil, client.WithCache(time.Minute))
+		// have used the cache. The correct value should be set on both responses and no errors should
+		// be returned.
+		rsp1 := &testRsp{}
+		rsp2 := &testRsp{}
+		err1 := w.Call(context.TODO(), req, rsp1, client.WithCache(time.Minute))
+		err2 := w.Call(context.TODO(), req, rsp2, client.WithCache(time.Minute))
 
 		if err1 != nil {
 			t.Errorf("Expected nil error, got %v", err1)
@@ -115,6 +136,14 @@ func TestCacheWrapper(t *testing.T) {
 		if err2 != nil {
 			t.Errorf("Expected nil error, got %v", err2)
 		}
+
+		if rsp1.value != val {
+			t.Errorf("Expected %v to be assigned to the value, got %v", val, rsp1.value)
+		}
+		if rsp2.value != val {
+			t.Errorf("Expected %v to be assigned to the value, got %v", val, rsp2.value)
+		}
+
 		if cli.callCount != 1 {
 			t.Errorf("Expected the client to be called 1 time, was actually called %v time(s)", cli.callCount)
 		}