utils: export ParseFloat and MustParseFloat wrapping internal utils (#3371)

* utils: expose ParseFloat via new public utils package

* add tests for special float values in vector search

helper/helper.go

@@ -0,0 +1,11 @@
+package helper
+
+import "github.com/redis/go-redis/v9/internal/util"
+
+func ParseFloat(s string) (float64, error) {
+	return util.ParseStringToFloat(s)
+}
+
+func MustParseFloat(s string) float64 {
+	return util.MustParseFloat(s)
+}

internal/util/convert.go

@@ -0,0 +1,30 @@
+package util
+
+import (
+	"fmt"
+	"math"
+	"strconv"
+)
+
+// ParseFloat parses a Redis RESP3 float reply into a Go float64,
+// handling "inf", "-inf", "nan" per Redis conventions.
+func ParseStringToFloat(s string) (float64, error) {
+	switch s {
+	case "inf":
+		return math.Inf(1), nil
+	case "-inf":
+		return math.Inf(-1), nil
+	case "nan", "-nan":
+		return math.NaN(), nil
+	}
+	return strconv.ParseFloat(s, 64)
+}
+
+// MustParseFloat is like ParseFloat but panics on parse errors.
+func MustParseFloat(s string) float64 {
+	f, err := ParseStringToFloat(s)
+	if err != nil {
+		panic(fmt.Sprintf("redis: failed to parse float %q: %v", s, err))
+	}
+	return f
+}

internal/util/convert_test.go

@@ -0,0 +1,40 @@
+package util
+
+import (
+	"math"
+	"testing"
+)
+
+func TestParseStringToFloat(t *testing.T) {
+	tests := []struct {
+		in   string
+		want float64
+		ok   bool
+	}{
+		{"1.23", 1.23, true},
+		{"inf", math.Inf(1), true},
+		{"-inf", math.Inf(-1), true},
+		{"nan", math.NaN(), true},
+		{"oops", 0, false},
+	}
+
+	for _, tc := range tests {
+		got, err := ParseStringToFloat(tc.in)
+		if tc.ok {
+			if err != nil {
+				t.Fatalf("ParseFloat(%q) error: %v", tc.in, err)
+			}
+			if math.IsNaN(tc.want) {
+				if !math.IsNaN(got) {
+					t.Errorf("ParseFloat(%q) = %v; want NaN", tc.in, got)
+				}
+			} else if got != tc.want {
+				t.Errorf("ParseFloat(%q) = %v; want %v", tc.in, got, tc.want)
+			}
+		} else {
+			if err == nil {
+				t.Errorf("ParseFloat(%q) expected error, got nil", tc.in)
+			}
+		}
+	}
+}

search_test.go

@@ -1,15 +1,18 @@
 package redis_test
 
 import (
+	"bytes"
 	"context"
+	"encoding/binary"
 	"fmt"
-	"strconv"
+	"math"
 	"strings"
 	"time"
 
 	. "github.com/bsm/ginkgo/v2"
 	. "github.com/bsm/gomega"
 	"github.com/redis/go-redis/v9"
+	"github.com/redis/go-redis/v9/helper"
 )
 
 func WaitForIndexing(c *redis.Client, index string) {
@@ -27,6 +30,14 @@ func WaitForIndexing(c *redis.Client, index string) {
 	}
 }
 
+func encodeFloat32Vector(vec []float32) []byte {
+	buf := new(bytes.Buffer)
+	for _, v := range vec {
+		binary.Write(buf, binary.LittleEndian, v)
+	}
+	return buf.Bytes()
+}
+
 var _ = Describe("RediSearch commands Resp 2", Label("search"), func() {
 	ctx := context.TODO()
 	var client *redis.Client
@@ -693,9 +704,9 @@ var _ = Describe("RediSearch commands Resp 2", Label("search"), func() {
 		Expect(err).NotTo(HaveOccurred())
 		Expect(res).ToNot(BeNil())
 		Expect(len(res.Rows)).To(BeEquivalentTo(2))
-		score1, err := strconv.ParseFloat(fmt.Sprintf("%s", res.Rows[0].Fields["__score"]), 64)
+		score1, err := helper.ParseFloat(fmt.Sprintf("%s", res.Rows[0].Fields["__score"]))
 		Expect(err).NotTo(HaveOccurred())
-		score2, err := strconv.ParseFloat(fmt.Sprintf("%s", res.Rows[1].Fields["__score"]), 64)
+		score2, err := helper.ParseFloat(fmt.Sprintf("%s", res.Rows[1].Fields["__score"]))
 		Expect(err).NotTo(HaveOccurred())
 		Expect(score1).To(BeNumerically(">", score2))
 
@@ -712,9 +723,9 @@ var _ = Describe("RediSearch commands Resp 2", Label("search"), func() {
 		Expect(err).NotTo(HaveOccurred())
 		Expect(resDM).ToNot(BeNil())
 		Expect(len(resDM.Rows)).To(BeEquivalentTo(2))
-		score1DM, err := strconv.ParseFloat(fmt.Sprintf("%s", resDM.Rows[0].Fields["__score"]), 64)
+		score1DM, err := helper.ParseFloat(fmt.Sprintf("%s", resDM.Rows[0].Fields["__score"]))
 		Expect(err).NotTo(HaveOccurred())
-		score2DM, err := strconv.ParseFloat(fmt.Sprintf("%s", resDM.Rows[1].Fields["__score"]), 64)
+		score2DM, err := helper.ParseFloat(fmt.Sprintf("%s", resDM.Rows[1].Fields["__score"]))
 		Expect(err).NotTo(HaveOccurred())
 		Expect(score1DM).To(BeNumerically(">", score2DM))
 
@@ -1684,6 +1695,56 @@ var _ = Describe("RediSearch commands Resp 2", Label("search"), func() {
 		Expect(resUint8.Docs[0].ID).To(BeEquivalentTo("doc1"))
 	})
 
+	It("should return special float scores in FT.SEARCH vecsim", Label("search", "ftsearch", "vecsim"), func() {
+		SkipBeforeRedisVersion(7.4, "doesn't work with older redis stack images")
+
+		vecField := &redis.FTFlatOptions{
+			Type:           "FLOAT32",
+			Dim:            2,
+			DistanceMetric: "IP",
+		}
+		_, err := client.FTCreate(ctx, "idx_vec",
+			&redis.FTCreateOptions{OnHash: true, Prefix: []interface{}{"doc:"}},
+			&redis.FieldSchema{FieldName: "vector", FieldType: redis.SearchFieldTypeVector, VectorArgs: &redis.FTVectorArgs{FlatOptions: vecField}}).Result()
+		Expect(err).NotTo(HaveOccurred())
+		WaitForIndexing(client, "idx_vec")
+
+		bigPos := []float32{1e38, 1e38}
+		bigNeg := []float32{-1e38, -1e38}
+		nanVec := []float32{float32(math.NaN()), 0}
+		negNanVec := []float32{float32(math.Copysign(math.NaN(), -1)), 0}
+
+		client.HSet(ctx, "doc:1", "vector", encodeFloat32Vector(bigPos))
+		client.HSet(ctx, "doc:2", "vector", encodeFloat32Vector(bigNeg))
+		client.HSet(ctx, "doc:3", "vector", encodeFloat32Vector(nanVec))
+		client.HSet(ctx, "doc:4", "vector", encodeFloat32Vector(negNanVec))
+
+		searchOptions := &redis.FTSearchOptions{WithScores: true, Params: map[string]interface{}{"vec": encodeFloat32Vector(bigPos)}}
+		res, err := client.FTSearchWithArgs(ctx, "idx_vec", "*=>[KNN 4 @vector $vec]", searchOptions).Result()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(res.Total).To(BeEquivalentTo(4))
+
+		var scores []float64
+		for _, row := range res.Docs {
+			raw := fmt.Sprintf("%v", row.Fields["__vector_score"])
+			f, err := helper.ParseFloat(raw)
+			Expect(err).NotTo(HaveOccurred())
+			scores = append(scores, f)
+		}
+
+		Expect(scores).To(ContainElement(BeNumerically("==", math.Inf(1))))
+		Expect(scores).To(ContainElement(BeNumerically("==", math.Inf(-1))))
+
+		// For NaN values, use a custom check since NaN != NaN in floating point math
+		nanCount := 0
+		for _, score := range scores {
+			if math.IsNaN(score) {
+				nanCount++
+			}
+		}
+		Expect(nanCount).To(Equal(2))
+	})
+
 	It("should fail when using a non-zero offset with a zero limit", Label("search", "ftsearch"), func() {
 		SkipBeforeRedisVersion(7.9, "requires Redis 8.x")
 		val, err := client.FTCreate(ctx, "testIdx", &redis.FTCreateOptions{}, &redis.FieldSchema{