Merge pull request #11 from kenshin579/feat/#10-empty

[#10] not to store empty response in the cache

cache.go

@@ -34,6 +34,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -84,7 +85,7 @@ type (
 		Header http.Header `json:"header"`
 
 		// Expiration is the cached response Expiration date.
-		Expiration time.Time `json:"Expiration"`
+		Expiration time.Time `json:"expiration"`
 
 		// LastAccess is the last date a cached response was accessed.
 		// Used by LRU and MRU algorithms.
@@ -129,7 +130,7 @@ func CacheWithConfig(config CacheConfig) echo.MiddlewareFunc {
 		panic("Store configuration must be provided")
 	}
 	if config.Expiration < 1 {
-		panic("Cache Expiration must be provided")
+		panic("Cache expiration must be provided")
 	}
 
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
@@ -157,12 +158,11 @@ func CacheWithConfig(config CacheConfig) echo.MiddlewareFunc {
 					config.Store.Release(key)
 				} else {
 					if cachedResponse, ok := config.Store.Get(key); ok {
-						response := bytesToResponse(cachedResponse)
+						response := toCacheResponse(cachedResponse)
 						now := time.Now()
 						if response.Expiration.After(now) {
 							response.LastAccess = now
 							response.Frequency++
-
 							config.Store.Set(key, response.bytes(), response.Expiration)
 
 							for k, v := range response.Header {
@@ -198,7 +198,9 @@ func CacheWithConfig(config CacheConfig) echo.MiddlewareFunc {
 						LastAccess: now,
 						Frequency:  1,
 					}
-					config.Store.Set(key, response.bytes(), response.Expiration)
+					if !isAllFieldsEmpty(value) {
+						config.Store.Set(key, response.bytes(), response.Expiration)
+					}
 				}
 				return nil
 			}
@@ -257,8 +259,8 @@ func (r CacheResponse) bytes() []byte {
 	return data
 }
 
-// bytesToResponse converts bytes array into CacheResponse data structure.
-func bytesToResponse(b []byte) CacheResponse {
+// toCacheResponse converts bytes array into CacheResponse data structure.
+func toCacheResponse(b []byte) CacheResponse {
 	var r CacheResponse
 	dec := json.NewDecoder(bytes.NewReader(b))
 	dec.Decode(&r)
@@ -287,3 +289,22 @@ func generateKey(method, URL string) uint64 {
 
 	return hash.Sum64()
 }
+
+func isAllFieldsEmpty(inter any) bool {
+	val := reflect.ValueOf(inter)
+	if val.IsZero() {
+		return true
+	}
+
+	if val.Kind() != reflect.Struct {
+		return false
+	}
+
+	for i := 0; i < val.NumField(); i++ {
+		field := val.Field(i)
+		if !field.IsZero() {
+			return false
+		}
+	}
+	return true
+}

cache_test.go

@@ -155,7 +155,7 @@ func TestCache_panicBehavior(t *testing.T) {
 	})
 }
 
-func Test_bytesToResponse(t *testing.T) {
+func Test_toCacheResponse(t *testing.T) {
 	r := CacheResponse{
 		Value:      []byte("value 1"),
 		Expiration: time.Time{},
@@ -177,13 +177,13 @@ func Test_bytesToResponse(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := bytesToResponse(tt.b)
+			got := toCacheResponse(tt.b)
 			assert.Equal(t, tt.wantValue, string(got.Value))
 		})
 	}
 }
 
-func Test_nytes(t *testing.T) {
+func Test_bytes(t *testing.T) {
 	r := CacheResponse{
 		Value:      []byte("test"),
 		Expiration: time.Time{},
@@ -192,7 +192,7 @@ func Test_nytes(t *testing.T) {
 	}
 
 	bytes := r.bytes()
-	assert.Equal(t, `{"value":"dGVzdA==","header":null,"Expiration":"0001-01-01T00:00:00Z","lastAccess":"0001-01-01T00:00:00Z","frequency":1}`, string(bytes))
+	assert.Equal(t, `{"value":"dGVzdA==","header":null,"expiration":"0001-01-01T00:00:00Z","lastAccess":"0001-01-01T00:00:00Z","frequency":1}`, string(bytes))
 }
 
 func Test_keyAsString(t *testing.T) {

memory.go

@@ -143,7 +143,7 @@ func (store *CacheMemoryStore) evict() {
 	}
 
 	for k, v := range store.store {
-		r := bytesToResponse(v)
+		r := toCacheResponse(v)
 		switch store.algorithm {
 		case LRU:
 			if r.LastAccess.Before(lastAccess) {

memory_test.go

@@ -47,7 +47,7 @@ func TestGet(t *testing.T) {
 			b, ok := store.Get(tt.key)
 			assert.Equal(t, tt.ok, ok)
 
-			got := bytesToResponse(b).Value
+			got := toCacheResponse(b).Value
 			assert.Equal(t, tt.want, got)
 		})
 	}
@@ -94,7 +94,7 @@ func TestSet(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			store.Set(tt.key, tt.response.bytes(), tt.response.Expiration)
-			if bytesToResponse(store.store[tt.key]).Value == nil {
+			if toCacheResponse(store.store[tt.key]).Value == nil {
 				t.Errorf(
 					"memory.Set() error = store[%v] response is not %s", tt.key, tt.response.Value,
 				)

redis_test.go

@@ -41,7 +41,7 @@ func (suite *cacheRedisStoreTestSuite) SetupSuite() {
 	suite.echo.Use(CacheWithConfig(CacheConfig{
 		Store:        store,
 		Expiration:   5 * time.Second,
-		IncludePaths: []string{"/test"},
+		IncludePaths: []string{"/test", "/empty"},
 	}))
 }
 
@@ -74,7 +74,11 @@ func (suite *cacheRedisStoreTestSuite) Test_Echo_CacheWithConfig() {
 		return c.String(http.StatusOK, "test")
 	})
 
-	suite.Run("echo cache test with redis store", func() {
+	suite.echo.GET("/empty", func(c echo.Context) error {
+		return c.String(http.StatusOK, "")
+	})
+
+	suite.Run("GET /test with non empty body", func() {
 		req := httptest.NewRequest(http.MethodGet, "/test", nil)
 		rec := httptest.NewRecorder()
 
@@ -92,4 +96,18 @@ func (suite *cacheRedisStoreTestSuite) Test_Echo_CacheWithConfig() {
 		suite.NoError(err)
 		suite.Equal("test", string(cacheResponse.Value))
 	})
+
+	suite.Run("GET /empty", func() {
+		req := httptest.NewRequest(http.MethodGet, "/empty", nil)
+		rec := httptest.NewRecorder()
+
+		suite.echo.ServeHTTP(rec, req)
+
+		suite.Equal(http.StatusOK, rec.Code)
+		suite.Equal("", rec.Body.String())
+
+		key := generateKey(http.MethodGet, "/empty")
+		_, ok := suite.cacheStore.Get(key)
+		suite.False(ok)
+	})
 }