add ZInter command (#1768)

commands.go

@@ -254,6 +254,8 @@ type Cmdable interface {
 	ZCount(ctx context.Context, key, min, max string) *IntCmd
 	ZLexCount(ctx context.Context, key, min, max string) *IntCmd
 	ZIncrBy(ctx context.Context, key string, increment float64, member string) *FloatCmd
+	ZInter(ctx context.Context, store *ZStore) *StringSliceCmd
+	ZInterWithScores(ctx context.Context, store *ZStore) *ZSliceCmd
 	ZInterStore(ctx context.Context, destination string, store *ZStore) *IntCmd
 	ZMScore(ctx context.Context, key string, members ...string) *FloatSliceCmd
 	ZPopMax(ctx context.Context, key string, count ...int64) *ZSliceCmd
@@ -1943,6 +1945,17 @@ type ZStore struct {
 	Aggregate string
 }
 
+func (z *ZStore) len() (n int) {
+	n = len(z.Keys)
+	if len(z.Weights) > 0 {
+		n += 1 + len(z.Weights)
+	}
+	if z.Aggregate != "" {
+		n += 2
+	}
+	return n
+}
+
 // Redis `BZPOPMAX key [key ...] timeout` command.
 func (c cmdable) BZPopMax(ctx context.Context, timeout time.Duration, keys ...string) *ZWithKeyCmd {
 	args := make([]interface{}, 1+len(keys)+1)
@@ -2088,7 +2101,7 @@ func (c cmdable) ZIncrBy(ctx context.Context, key string, increment float64, mem
 }
 
 func (c cmdable) ZInterStore(ctx context.Context, destination string, store *ZStore) *IntCmd {
-	args := make([]interface{}, 0, 3+len(store.Keys))
+	args := make([]interface{}, 0, 3+store.len())
 	args = append(args, "zinterstore", destination, len(store.Keys))
 	for _, key := range store.Keys {
 		args = append(args, key)
@@ -2108,6 +2121,50 @@ func (c cmdable) ZInterStore(ctx context.Context, destination string, store *ZSt
 	return cmd
 }
 
+func (c cmdable) ZInter(ctx context.Context, store *ZStore) *StringSliceCmd {
+	args := make([]interface{}, 0, 2+store.len())
+	args = append(args, "zinter", len(store.Keys))
+	for _, key := range store.Keys {
+		args = append(args, key)
+	}
+	if len(store.Weights) > 0 {
+		args = append(args, "weights")
+		for _, weights := range store.Weights {
+			args = append(args, weights)
+		}
+	}
+
+	if store.Aggregate != "" {
+		args = append(args, "aggregate", store.Aggregate)
+	}
+	cmd := NewStringSliceCmd(ctx, args...)
+	cmd.setFirstKeyPos(2)
+	_ = c(ctx, cmd)
+	return cmd
+}
+
+func (c cmdable) ZInterWithScores(ctx context.Context, store *ZStore) *ZSliceCmd {
+	args := make([]interface{}, 0, 3+store.len())
+	args = append(args, "zinter", len(store.Keys))
+	for _, key := range store.Keys {
+		args = append(args, key)
+	}
+	if len(store.Weights) > 0 {
+		args = append(args, "weights")
+		for _, weights := range store.Weights {
+			args = append(args, weights)
+		}
+	}
+	if store.Aggregate != "" {
+		args = append(args, "aggregate", store.Aggregate)
+	}
+	args = append(args, "withscores")
+	cmd := NewZSliceCmd(ctx, args...)
+	cmd.setFirstKeyPos(2)
+	_ = c(ctx, cmd)
+	return cmd
+}
+
 func (c cmdable) ZMScore(ctx context.Context, key string, members ...string) *FloatSliceCmd {
 	args := make([]interface{}, 2+len(members))
 	args[0] = "zmscore"
@@ -2334,7 +2391,7 @@ func (c cmdable) ZScore(ctx context.Context, key, member string) *FloatCmd {
 }
 
 func (c cmdable) ZUnionStore(ctx context.Context, dest string, store *ZStore) *IntCmd {
-	args := make([]interface{}, 0, 3+len(store.Keys))
+	args := make([]interface{}, 0, 3+store.len())
 	args = append(args, "zunionstore", dest, len(store.Keys))
 	for _, key := range store.Keys {
 		args = append(args, key)

commands_test.go

@@ -3999,6 +3999,55 @@ var _ = Describe("Commands", func() {
 				},
 			}))
 		})
+
+		It("should ZInter", func() {
+			err := client.ZAdd(ctx, "zset1", &redis.Z{Score: 1, Member: "one"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset1", &redis.Z{Score: 2, Member: "two"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset2", &redis.Z{Score: 1, Member: "one"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset2", &redis.Z{Score: 2, Member: "two"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset2", &redis.Z{Score: 3, Member: "three"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+
+			v, err := client.ZInter(ctx, &redis.ZStore{
+				Keys: []string{"zset1", "zset2"},
+			}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(v).To(Equal([]string{"one", "two"}))
+		})
+
+		It("should ZInterWithScores", func() {
+			err := client.ZAdd(ctx, "zset1", &redis.Z{Score: 1, Member: "one"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset1", &redis.Z{Score: 2, Member: "two"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset2", &redis.Z{Score: 1, Member: "one"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset2", &redis.Z{Score: 2, Member: "two"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+			err = client.ZAdd(ctx, "zset2", &redis.Z{Score: 3, Member: "three"}).Err()
+			Expect(err).NotTo(HaveOccurred())
+
+			v, err := client.ZInterWithScores(ctx, &redis.ZStore{
+				Keys:      []string{"zset1", "zset2"},
+				Weights:   []float64{2, 3},
+				Aggregate: "Max",
+			}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(v).To(Equal([]redis.Z{
+				{
+					Member: "one",
+					Score:  3,
+				},
+				{
+					Member: "two",
+					Score:  6,
+				},
+			}))
+		})
 	})
 
 	Describe("streams", func() {