api: created constructors for predicates

Closes #TNTP-4539.

Author: bigbes

go.mod

@@ -3,28 +3,32 @@ module github.com/tarantool/go-storage
 go 1.24.0
 
 require (
+	github.com/stretchr/testify v1.11.1
 	github.com/tarantool/go-tarantool/v2 v2.4.0
-	go.etcd.io/etcd/client/v3 v3.6.4
+	go.etcd.io/etcd/client/v3 v3.6.5
 )
 
 require (
 	github.com/coreos/go-semver v0.3.1 // indirect
 	github.com/coreos/go-systemd/v22 v22.6.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/tarantool/go-iproto v1.1.0 // indirect
 	github.com/vmihailenco/msgpack/v5 v5.4.1 // indirect
 	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
-	go.etcd.io/etcd/api/v3 v3.6.4 // indirect
-	go.etcd.io/etcd/client/pkg/v3 v3.6.4 // indirect
+	go.etcd.io/etcd/api/v3 v3.6.5 // indirect
+	go.etcd.io/etcd/client/pkg/v3 v3.6.5 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap v1.27.0 // indirect
 	golang.org/x/net v0.44.0 // indirect
 	golang.org/x/sys v0.36.0 // indirect
 	golang.org/x/text v0.29.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20250908214217-97024824d090 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20250908214217-97024824d090 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9 // indirect
 	google.golang.org/grpc v1.75.1 // indirect
 	google.golang.org/protobuf v1.36.9 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -20,10 +20,16 @@ github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.2 h1:8Tjv8EJ+pM1xP8mK6egEbD1OgnV
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.2/go.mod h1:pkJQ2tZHJ0aFOVEEot6oZmaVEZcRme73eIFmhiVuRWs=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
-github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/tarantool/go-iproto v1.1.0 h1:HULVOIHsiehI+FnHfM7wMDntuzUddO09DKqu2WnFQ5A=
 github.com/tarantool/go-iproto v1.1.0/go.mod h1:LNCtdyZxojUed8SbOiYHoc3v9NvaZTB7p96hUySMlIo=
 github.com/tarantool/go-tarantool/v2 v2.4.0 h1:cfGngxdknpVVbd/vF2LvaoWsKjsLV9i3xC859XgsJlI=
@@ -34,12 +40,12 @@ github.com/vmihailenco/tagparser/v2 v2.0.0 h1:y09buUbR+b5aycVFQs/g70pqKVZNBmxwAh
 github.com/vmihailenco/tagparser/v2 v2.0.0/go.mod h1:Wri+At7QHww0WTrCBeu4J6bNtoV6mEfg5OIWRZA9qds=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-go.etcd.io/etcd/api/v3 v3.6.4 h1:7F6N7toCKcV72QmoUKa23yYLiiljMrT4xCeBL9BmXdo=
-go.etcd.io/etcd/api/v3 v3.6.4/go.mod h1:eFhhvfR8Px1P6SEuLT600v+vrhdDTdcfMzmnxVXXSbk=
-go.etcd.io/etcd/client/pkg/v3 v3.6.4 h1:9HBYrjppeOfFjBjaMTRxT3R7xT0GLK8EJMVC4xg6ok0=
-go.etcd.io/etcd/client/pkg/v3 v3.6.4/go.mod h1:sbdzr2cl3HzVmxNw//PH7aLGVtY4QySjQFuaCgcRFAI=
-go.etcd.io/etcd/client/v3 v3.6.4 h1:YOMrCfMhRzY8NgtzUsHl8hC2EBSnuqbR3dh84Uryl7A=
-go.etcd.io/etcd/client/v3 v3.6.4/go.mod h1:jaNNHCyg2FdALyKWnd7hxZXZxZANb0+KGY+YQaEMISo=
+go.etcd.io/etcd/api/v3 v3.6.5 h1:pMMc42276sgR1j1raO/Qv3QI9Af/AuyQUW6CBAWuntA=
+go.etcd.io/etcd/api/v3 v3.6.5/go.mod h1:ob0/oWA/UQQlT1BmaEkWQzI0sJ1M0Et0mMpaABxguOQ=
+go.etcd.io/etcd/client/pkg/v3 v3.6.5 h1:Duz9fAzIZFhYWgRjp/FgNq2gO1jId9Yae/rLn3RrBP8=
+go.etcd.io/etcd/client/pkg/v3 v3.6.5/go.mod h1:8Wx3eGRPiy0qOFMZT/hfvdos+DjEaPxdIDiCDUv/FQk=
+go.etcd.io/etcd/client/v3 v3.6.5 h1:yRwZNFBx/35VKHTcLDeO7XVLbCBFbPi+XV4OC3QJf2U=
+go.etcd.io/etcd/client/v3 v3.6.5/go.mod h1:ZqwG/7TAFZ0BJ0jXRPoJjKQJtbFo/9NIY8uoFFKcCyo=
 go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
 go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
 go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
@@ -91,14 +97,16 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/genproto/googleapis/api v0.0.0-20250908214217-97024824d090 h1:d8Nakh1G+ur7+P3GcMjpRDEkoLUcLW2iU92XVqR+XMQ=
-google.golang.org/genproto/googleapis/api v0.0.0-20250908214217-97024824d090/go.mod h1:U8EXRNSd8sUYyDfs/It7KVWodQr+Hf9xtxyxWudSwEw=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20250908214217-97024824d090 h1:/OQuEa4YWtDt7uQWHd3q3sUMb+QOLQUg1xa8CEsRv5w=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20250908214217-97024824d090/go.mod h1:GmFNa4BdJZ2a8G+wCe9Bg3wwThLrJun751XstdJt5Og=
+google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9 h1:jm6v6kMRpTYKxBRrDkYAitNJegUeO1Mf3Kt80obv0gg=
+google.golang.org/genproto/googleapis/api v0.0.0-20250922171735-9219d122eba9/go.mod h1:LmwNphe5Afor5V3R5BppOULHOnt2mCIf+NxMd4XiygE=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9 h1:V1jCN2HBa8sySkR5vLcCSqJSTMv093Rw9EJefhQGP7M=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250922171735-9219d122eba9/go.mod h1:HSkG/KdJWusxU1F6CNrwNDjBMgisKxGnc5dAZfT0mjQ=
 google.golang.org/grpc v1.75.1 h1:/ODCNEuf9VghjgO3rqLcfg8fiOP0nSluljWFlDxELLI=
 google.golang.org/grpc v1.75.1/go.mod h1:JtPAzKiq4v1xcAB2hydNlWI2RnF85XXcV0mhKXr2ecQ=
 google.golang.org/protobuf v1.36.9 h1:w2gp2mA27hUeUzj9Ex9FBjsBm40zfaDtEWow293U7Iw=
 google.golang.org/protobuf v1.36.9/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

predicate/op_test.go

@@ -0,0 +1,34 @@
+package predicate_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/tarantool/go-storage/predicate"
+)
+
+func TestOpString(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name     string
+		op       predicate.Op
+		expected string
+	}{
+		{"OpEqual", predicate.OpEqual, "Equal"},
+		{"OpNotEqual", predicate.OpNotEqual, "NotEqual"},
+		{"OpGreater", predicate.OpGreater, "Greater"},
+		{"OpLess", predicate.OpLess, "Less"},
+		{"UnknownOp", predicate.Op(99), "Unknown"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			result := tt.op.String()
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}

predicate/predicate.go

@@ -14,3 +14,92 @@ type Predicate interface {
 	// Value returns the comparison value for the predicate.
 	Value() any
 }
+
+// predicate is the concrete implementation of the Predicate interface.
+// It represents a condition used for conditional operations in transactions.
+type predicate struct {
+	key    []byte
+	op     Op
+	target Target
+	value  interface{}
+}
+
+// Key returns the key that this predicate applies to.
+func (p predicate) Key() []byte {
+	return p.key
+}
+
+// Operation returns the comparison operation (Equal, NotEqual, Greater, Less).
+func (p predicate) Operation() Op {
+	return p.op
+}
+
+// Target returns what aspect of the record to compare (e.g. Version or Value).
+func (p predicate) Target() Target {
+	return p.target
+}
+
+// Value returns the comparison value for the predicate.
+func (p predicate) Value() interface{} {
+	return p.value
+}
+
+// ValueNotEqual creates a predicate that checks if a key's value is not equal to the specified value.
+func ValueNotEqual(key []byte, value interface{}) Predicate {
+	return &predicate{
+		key:    key,
+		op:     OpNotEqual,
+		target: TargetValue,
+		value:  value,
+	}
+}
+
+// ValueEqual creates a predicate that checks if a key's value equals the specified value.
+func ValueEqual(key []byte, value interface{}) Predicate {
+	return &predicate{
+		key:    key,
+		op:     OpEqual,
+		target: TargetValue,
+		value:  value,
+	}
+}
+
+// VersionEqual creates a predicate that checks if a key's version equals the specified version.
+func VersionEqual(key []byte, version int64) Predicate {
+	return &predicate{
+		key:    key,
+		op:     OpEqual,
+		target: TargetVersion,
+		value:  version,
+	}
+}
+
+// VersionNotEqual creates a predicate that checks if a key's version is not equal to the specified version.
+func VersionNotEqual(key []byte, version int64) Predicate {
+	return &predicate{
+		key:    key,
+		op:     OpNotEqual,
+		target: TargetVersion,
+		value:  version,
+	}
+}
+
+// VersionGreater creates a predicate that checks if a key's version is greater than the specified version.
+func VersionGreater(key []byte, version int64) Predicate {
+	return &predicate{
+		key:    key,
+		op:     OpGreater,
+		target: TargetVersion,
+		value:  version,
+	}
+}
+
+// VersionLess creates a predicate that checks if a key's version is less than the specified version.
+func VersionLess(key []byte, version int64) Predicate {
+	return &predicate{
+		key:    key,
+		op:     OpLess,
+		target: TargetVersion,
+		value:  version,
+	}
+}

predicate/predicate_test.go

@@ -0,0 +1,87 @@
+package predicate_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/tarantool/go-storage/predicate"
+)
+
+func TestValueNotEqual(t *testing.T) {
+	t.Parallel()
+
+	key := []byte("test-key")
+	value := "test-value"
+	p := predicate.ValueNotEqual(key, value)
+
+	assert.Equal(t, key, p.Key())
+	assert.Equal(t, predicate.OpNotEqual, p.Operation())
+	assert.Equal(t, predicate.TargetValue, p.Target())
+	assert.Equal(t, value, p.Value())
+}
+
+func TestValueEqual(t *testing.T) {
+	t.Parallel()
+
+	key := []byte("test-key")
+	value := 42
+	p := predicate.ValueEqual(key, value)
+
+	assert.Equal(t, key, p.Key())
+	assert.Equal(t, predicate.OpEqual, p.Operation())
+	assert.Equal(t, predicate.TargetValue, p.Target())
+	assert.Equal(t, value, p.Value())
+}
+
+func TestVersionEqual(t *testing.T) {
+	t.Parallel()
+
+	key := []byte("test-key")
+	version := int64(123)
+	p := predicate.VersionEqual(key, version)
+
+	assert.Equal(t, key, p.Key())
+	assert.Equal(t, predicate.OpEqual, p.Operation())
+	assert.Equal(t, predicate.TargetVersion, p.Target())
+	assert.Equal(t, version, p.Value())
+}
+
+func TestVersionNotEqual(t *testing.T) {
+	t.Parallel()
+
+	key := []byte("test-key")
+	version := int64(456)
+	p := predicate.VersionNotEqual(key, version)
+
+	assert.Equal(t, key, p.Key())
+	assert.Equal(t, predicate.OpNotEqual, p.Operation())
+	assert.Equal(t, predicate.TargetVersion, p.Target())
+	assert.Equal(t, version, p.Value())
+}
+
+func TestVersionGreater(t *testing.T) {
+	t.Parallel()
+
+	key := []byte("test-key")
+	version := int64(789)
+	p := predicate.VersionGreater(key, version)
+
+	assert.Equal(t, key, p.Key())
+	assert.Equal(t, predicate.OpGreater, p.Operation())
+	assert.Equal(t, predicate.TargetVersion, p.Target())
+	assert.Equal(t, version, p.Value())
+}
+
+func TestVersionLess(t *testing.T) {
+	t.Parallel()
+
+	key := []byte("test-key")
+	version := int64(999)
+	p := predicate.VersionLess(key, version)
+
+	assert.Equal(t, key, p.Key())
+	assert.Equal(t, predicate.OpLess, p.Operation())
+	assert.Equal(t, predicate.TargetVersion, p.Target())
+	assert.Equal(t, version, p.Value())
+}

predicate/target_test.go

@@ -0,0 +1,32 @@
+package predicate_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/tarantool/go-storage/predicate"
+)
+
+func TestTargetString(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name     string
+		target   predicate.Target
+		expected string
+	}{
+		{"TargetVersion", predicate.TargetVersion, "Version"},
+		{"TargetValue", predicate.TargetValue, "Value"},
+		{"UnknownTarget", predicate.Target(99), "Unknown"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			result := tt.target.String()
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}