Add the LLEN command

wredis_lists.go

@@ -31,6 +31,19 @@ func (w *Wredis) RPop(key string) (string, error) {
 		return stringError("key cannot be empty")
 	}
 	return w.ExecString(func(conn redis.Conn) (string, error) {
-		return redis.String(conn.Do("RPOP", key))
+		args := redis.Args{}.Add(key)
+		return redis.String(conn.Do("RPOP", args...))
+	})
+}
+
+// LLen returns the length of the list stored at key. For more information, see
+// http://redis.io/commands/llen.
+func (w *Wredis) LLen(key string) (int64, error) {
+	if key == "" {
+		return int64Error("key cannot be empty")
+	}
+	return w.ExecInt64(func(conn redis.Conn) (int64, error) {
+		args := redis.Args{}.Add(key)
+		return redis.Int64(conn.Do("LLEN", args...))
 	})
 }

wredis_lists_test.go

@@ -9,11 +9,11 @@ var _ = Describe("WredisLists", func() {
 
 	var testList = "wredis::test::list"
 
-	Context("LPush", func() {
-		BeforeEach(func() {
-			unsafe.Del(testList)
-		})
+	BeforeEach(func() {
+		unsafe.Del(testList)
+	})
 
+	Context("LPush", func() {
 		It("should return an error when no key provided", func() {
 			_, err := safe.LPush("")
 			Ω(err).Should(HaveOccurred())
@@ -50,10 +50,6 @@ var _ = Describe("WredisLists", func() {
 	})
 
 	Context("RPop", func() {
-		BeforeEach(func() {
-			unsafe.Del(testList)
-		})
-
 		It("should return an error when no key provided", func() {
 			_, err := safe.RPop("")
 			Ω(err).Should(HaveOccurred())
@@ -76,4 +72,26 @@ var _ = Describe("WredisLists", func() {
 			Ω(i).Should(Equal("1"))
 		})
 	})
+
+	Context("LLen", func() {
+		It("should return an error when no key provided", func() {
+			_, err := safe.LLen("")
+			Ω(err).Should(HaveOccurred())
+			Ω(err.Error()).Should(Equal("key cannot be empty"))
+		})
+
+		It("should return 0 when the list doesn't exist", func() {
+			i, err := safe.LLen(testList)
+			Ω(err).ShouldNot(HaveOccurred())
+			Ω(i).Should(Equal(int64(0)))
+		})
+
+		It("should return the length of the list", func() {
+			_, err := safe.LPush(testList, "1", "2", "3")
+			Ω(err).ShouldNot(HaveOccurred())
+			i, err := safe.LLen(testList)
+			Ω(err).ShouldNot(HaveOccurred())
+			Ω(i).Should(Equal(int64(3)))
+		})
+	})
 })