Add del function

Delete key feature added with its tests. Example usage added to pkg/main.go and README.
README updated.

Signed-off-by: Gökhan Özeloğlu <gozeloglu@gmail.com>

README.md

@@ -76,6 +76,11 @@ func main() {
 	jackAge := db.Get("jack")
 	fmt.Println(jackAge)
 
+	db.Del("jack")
+
+	jack = db.Get("jack")
+	fmt.Println("Jack:", jack)
+
 	err = db.Close() // Call while closing the database.
 	if err != nil {
 		log.Fatalf(err.Error())
@@ -136,11 +141,11 @@ john=12
 fizz=buzz
 ```
 
-This is a sample data file. If you want to save data manually,>
+This is a sample data file.
 
 ## NOTE
 
-kvs is still under development stage, and it is created for experimental purposes. 
+kvs is still under development stage, and it is created for experimental purposes.
 
 ## LICENSE
 

del.go

@@ -0,0 +1,5 @@
+package kvs
+
+func (k *Kvs) Del(key string) {
+	delete(k.kv, key)
+}

del_test.go

@@ -0,0 +1,90 @@
+package kvs
+
+import (
+	"os"
+	"testing"
+	"time"
+)
+
+func TestDel(t *testing.T) {
+	db, err := open(t.Name(), "", 2*time.Minute)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db created.")
+
+	k, v := "foo", "bar"
+	db.Set(k, v)
+
+	val := db.Get(k)
+	if val != v {
+		t.Logf("set value could not get.")
+	}
+
+	db.Del(k)
+	if db.Get(k) != "" {
+		t.Logf("key could not deleted.")
+	}
+
+	t.Logf("Key is deleted successfully.")
+
+	err = db.Close()
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db closed.")
+
+	err = os.RemoveAll(db.dir)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("test file removed.")
+}
+
+func TestDelWithTime(t *testing.T) {
+	db, err := open(t.Name(), "", 2*time.Second)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db created.")
+
+	k, v := "foo", "bar"
+	db.Set(k, v)
+	val := db.Get(k)
+	t.Logf("%s: %s", k, val)
+	db.Del(k)
+	val = db.Get(k)
+	if val != "" {
+		t.Errorf("val is not empty string: %s", val)
+	}
+	time.Sleep(3 * time.Second)
+
+	err = db.Close()
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db closed.")
+
+	tmpDb, err := open(t.Name(), "", 2*time.Minute)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("tmpdb created.")
+
+	val = tmpDb.Get(k)
+	if val != "" {
+		t.Errorf("val is not empty string: %s", val)
+	}
+
+	err = tmpDb.Close()
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db closed.")
+
+	err = os.RemoveAll(tmpDb.dir)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("tmp file removed.")
+}

example/pkg/main.go

@@ -20,7 +20,12 @@ func main() {
 	fmt.Println("John:", john)
 
 	jack := db.Get("jack")
-	fmt.Println("Jack", jack)
+	fmt.Println("Jack:", jack)
+
+	db.Del("jack")
+
+	jack = db.Get("jack")
+	fmt.Println("Jack:", jack)
 
 	err = db.Close()
 	if err != nil {