Break utils package into subpackages.

cmd/jet/main.go

@@ -6,6 +6,7 @@ import (
 	"flag"
 	"fmt"
 	"github.com/go-jet/jet/v2/internal/utils/errfmt"
+	"github.com/go-jet/jet/v2/internal/utils/strslice"
 	"os"
 	"strings"
 
@@ -13,7 +14,6 @@ import (
 	sqlitegen "github.com/go-jet/jet/v2/generator/sqlite"
 	"github.com/go-jet/jet/v2/generator/template"
 	"github.com/go-jet/jet/v2/internal/jet"
-	"github.com/go-jet/jet/v2/internal/utils"
 	"github.com/go-jet/jet/v2/mysql"
 	postgres2 "github.com/go-jet/jet/v2/postgres"
 	"github.com/go-jet/jet/v2/sqlite"
@@ -232,15 +232,15 @@ func parseList(list string) []string {
 func genTemplate(dialect jet.Dialect, ignoreTables []string, ignoreViews []string, ignoreEnums []string) template.Template {
 
 	shouldSkipTable := func(table metadata.Table) bool {
-		return utils.StringSliceContains(ignoreTables, strings.ToLower(table.Name))
+		return strslice.Contains(ignoreTables, strings.ToLower(table.Name))
 	}
 
 	shouldSkipView := func(view metadata.Table) bool {
-		return utils.StringSliceContains(ignoreViews, strings.ToLower(view.Name))
+		return strslice.Contains(ignoreViews, strings.ToLower(view.Name))
 	}
 
 	shouldSkipEnum := func(enum metadata.Enum) bool {
-		return utils.StringSliceContains(ignoreEnums, strings.ToLower(enum.Name))
+		return strslice.Contains(ignoreEnums, strings.ToLower(enum.Name))
 	}
 
 	return template.Default(dialect).

generator/mysql/mysql_generator.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/go-jet/jet/v2/generator/metadata"
 	"github.com/go-jet/jet/v2/generator/template"
-	"github.com/go-jet/jet/v2/internal/utils"
 	"github.com/go-jet/jet/v2/mysql"
 	mysqldr "github.com/go-sql-driver/mysql"
 )
@@ -35,7 +34,7 @@ func Generate(destDir string, dbConn DBConnection, generatorTemplate ...template
 	if err != nil {
 		return fmt.Errorf("failed to open db connection: %w", err)
 	}
-	defer utils.DBClose(db)
+	defer db.Close()
 
 	err = generate(db, dbConn.DBName, destDir, generatorTemplate...)
 	if err != nil {
@@ -67,7 +66,7 @@ func GenerateDSN(dsn, destDir string, templates ...template.Template) error {
 	if err != nil {
 		return fmt.Errorf("failed to open db connection: %w", err)
 	}
-	defer utils.DBClose(db)
+	defer db.Close()
 
 	err = generate(db, cfg.DBName, destDir, templates...)
 	if err != nil {

generator/postgres/postgres_generator.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/go-jet/jet/v2/generator/metadata"
 	"github.com/go-jet/jet/v2/generator/template"
-	"github.com/go-jet/jet/v2/internal/utils"
 	"github.com/go-jet/jet/v2/postgres"
 	"github.com/jackc/pgconn"
 )
@@ -54,7 +53,7 @@ func GenerateDSN(dsn, schema, destDir string, templates ...template.Template) er
 	if err != nil {
 		return fmt.Errorf("failed to open db connection: %w", err)
 	}
-	defer utils.DBClose(db)
+	defer db.Close()
 
 	fmt.Println("Retrieving schema information...")
 	generatorTemplate := template.Default(postgres.Dialect)

generator/sqlite/sqlite_generator.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"github.com/go-jet/jet/v2/generator/metadata"
 	"github.com/go-jet/jet/v2/generator/template"
-	"github.com/go-jet/jet/v2/internal/utils"
 	"github.com/go-jet/jet/v2/sqlite"
 )
 
@@ -15,7 +14,7 @@ func GenerateDSN(dsn, destDir string, templates ...template.Template) error {
 	if err != nil {
 		return fmt.Errorf("failed to open sqlite connection: %w", err)
 	}
-	defer utils.DBClose(db)
+	defer db.Close()
 
 	fmt.Println("Retrieving schema information...")
 

generator/template/model_template.go

@@ -3,7 +3,7 @@ package template
 import (
 	"fmt"
 	"github.com/go-jet/jet/v2/generator/metadata"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/dbidentifier"
 	"github.com/google/uuid"
 	"path"
 	"reflect"
@@ -77,8 +77,8 @@ var DefaultViewModel = DefaultTableModel
 // DefaultTableModel is default table template implementation
 func DefaultTableModel(tableMetaData metadata.Table) TableModel {
 	return TableModel{
-		FileName: utils.ToGoFileName(tableMetaData.Name),
+		FileName: dbidentifier.ToGoFileName(tableMetaData.Name),
-		TypeName: utils.ToGoIdentifier(tableMetaData.Name),
+		TypeName: dbidentifier.ToGoIdentifier(tableMetaData.Name),
 		Field:    DefaultTableModelField,
 	}
 }
@@ -142,13 +142,13 @@ func (em EnumModel) UseTypeName(typeName string) EnumModel {
 
 // DefaultEnumModel returns default implementation for EnumModel
 func DefaultEnumModel(enumMetaData metadata.Enum) EnumModel {
-	typeName := utils.ToGoIdentifier(enumMetaData.Name)
+	typeName := dbidentifier.ToGoIdentifier(enumMetaData.Name)
 
 	return EnumModel{
-		FileName: utils.ToGoFileName(enumMetaData.Name),
+		FileName: dbidentifier.ToGoFileName(enumMetaData.Name),
 		TypeName: typeName,
 		ValueName: func(value string) string {
-			return typeName + "_" + utils.ToGoIdentifier(value)
+			return typeName + "_" + dbidentifier.ToGoIdentifier(value)
 		},
 	}
 }
@@ -169,7 +169,7 @@ func DefaultTableModelField(columnMetaData metadata.Column) TableModelField {
 	}
 
 	return TableModelField{
-		Name: utils.ToGoIdentifier(columnMetaData.Name),
+		Name: dbidentifier.ToGoIdentifier(columnMetaData.Name),
 		Type: getType(columnMetaData),
 		Tags: tags,
 	}
@@ -247,7 +247,7 @@ func getType(columnMetadata metadata.Column) Type {
 func getUserDefinedType(column metadata.Column) string {
 	switch column.DataType.Kind {
 	case metadata.EnumType:
-		return utils.ToGoIdentifier(column.DataType.Name)
+		return dbidentifier.ToGoIdentifier(column.DataType.Name)
 	case metadata.UserDefinedType, metadata.ArrayType:
 		return "string"
 	}

generator/template/process.go

@@ -4,13 +4,13 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"github.com/go-jet/jet/v2/internal/utils/filesys"
 	"path"
 	"strings"
 	"text/template"
 
 	"github.com/go-jet/jet/v2/generator/metadata"
 	"github.com/go-jet/jet/v2/internal/jet"
-	"github.com/go-jet/jet/v2/internal/utils"
 )
 
 // ProcessSchema will process schema metadata and constructs go files using generator Template
@@ -24,7 +24,7 @@ func ProcessSchema(dirPath string, schemaMetaData metadata.Schema, generatorTemp
 
 	fmt.Println("Destination directory:", schemaPath)
 	fmt.Println("Cleaning up destination directory...")
-	err := utils.CleanUpGeneratedFiles(schemaPath)
+	err := filesys.RemoveDir(schemaPath)
 	if err != nil {
 		return errors.New("failed to cleanup generated files")
 	}
@@ -52,7 +52,7 @@ func processModel(dirPath string, schemaMetaData metadata.Schema, schemaTemplate
 
 	modelDirPath := path.Join(dirPath, modelTemplate.Path)
 
-	err := utils.EnsureDirPath(modelDirPath)
+	err := filesys.EnsureDirPathExist(modelDirPath)
 	if err != nil {
 		return fmt.Errorf("destination dir path does not exist: %w", err)
 	}
@@ -119,7 +119,7 @@ func processEnumSQLBuilder(dirPath string, dialect jet.Dialect, enumsMetaData []
 
 		enumSQLBuilderPath := path.Join(dirPath, enumTemplate.Path)
 
-		err := utils.EnsureDirPath(enumSQLBuilderPath)
+		err := filesys.EnsureDirPathExist(enumSQLBuilderPath)
 		if err != nil {
 			return fmt.Errorf("failed to create enum sql builder directory - %s: %w", enumSQLBuilderPath, err)
 		}
@@ -145,7 +145,7 @@ func processEnumSQLBuilder(dirPath string, dialect jet.Dialect, enumsMetaData []
 			return fmt.Errorf("failed to generete enum type %s: %w", enumTemplate.FileName, err)
 		}
 
-		err = utils.SaveGoFile(enumSQLBuilderPath, enumTemplate.FileName, text)
+		err = filesys.FormatAndSaveGoFile(enumSQLBuilderPath, enumTemplate.FileName, text)
 		if err != nil {
 			return fmt.Errorf("failed to format and save '%s' enum type : %w", enumTemplate.FileName, err)
 		}
@@ -183,7 +183,7 @@ func processTableSQLBuilder(fileTypes, dirPath string,
 
 		tableSQLBuilderPath := path.Join(dirPath, tableSQLBuilder.Path)
 
-		err := utils.EnsureDirPath(tableSQLBuilderPath)
+		err := filesys.EnsureDirPathExist(tableSQLBuilderPath)
 		if err != nil {
 			return fmt.Errorf("failed to create table sql builder directory - %s: %w", tableSQLBuilderPath, err)
 		}
@@ -220,7 +220,7 @@ func processTableSQLBuilder(fileTypes, dirPath string,
 			return fmt.Errorf("failed to generate table sql builder type %s: %w", tableSQLBuilder.TypeName, err)
 		}
 
-		err = utils.SaveGoFile(tableSQLBuilderPath, tableSQLBuilder.FileName, text)
+		err = filesys.FormatAndSaveGoFile(tableSQLBuilderPath, tableSQLBuilder.FileName, text)
 		if err != nil {
 			return fmt.Errorf("failed to format and save generated sql builder type '%s': %w", tableSQLBuilder.FileName, err)
 		}
@@ -256,7 +256,7 @@ func generateUseSchemaFunc(dirPath, fileTypes string, builders []TableSQLBuilder
 	basePath := path.Join(dirPath, builders[0].Path)
 	fileName := fileTypes + "_use_schema"
 
-	err = utils.SaveGoFile(basePath, fileName, text)
+	err = filesys.FormatAndSaveGoFile(basePath, fileName, text)
 	if err != nil {
 		return fmt.Errorf("failed to save %s file: %w", fileName, err)
 	}
@@ -312,7 +312,7 @@ func processTableModels(fileTypes, modelDirPath string, tablesMetaData []metadat
 			return fmt.Errorf("failed to generate model type '%s': %w", tableMetaData.Name, err)
 		}
 
-		err = utils.SaveGoFile(modelDirPath, tableTemplate.FileName, text)
+		err = filesys.FormatAndSaveGoFile(modelDirPath, tableTemplate.FileName, text)
 		if err != nil {
 			return fmt.Errorf("failed to save '%s' model type: %w", tableTemplate.FileName, err)
 		}
@@ -353,7 +353,7 @@ func processEnumModels(modelDir string, enumsMetaData []metadata.Enum, modelTemp
 			return fmt.Errorf("failed to generate enum type '%s': %w", enumMetaData.Name, err)
 		}
 
-		err = utils.SaveGoFile(modelDir, enumTemplate.FileName, text)
+		err = filesys.FormatAndSaveGoFile(modelDir, enumTemplate.FileName, text)
 		if err != nil {
 			return fmt.Errorf("failed to save '%s' enum type: %w", enumTemplate.FileName, err)
 		}

generator/template/sql_builder_template.go

@@ -3,7 +3,7 @@ package template
 import (
 	"fmt"
 	"github.com/go-jet/jet/v2/generator/metadata"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/dbidentifier"
 	"path"
 	"strings"
 	"unicode"
@@ -69,9 +69,9 @@ type ViewSQLBuilder = TableSQLBuilder
 func DefaultTableSQLBuilder(tableMetaData metadata.Table) TableSQLBuilder {
 	return TableSQLBuilder{
 		Path:         "/table",
-		FileName:     utils.ToGoFileName(tableMetaData.Name),
+		FileName:     dbidentifier.ToGoFileName(tableMetaData.Name),
-		InstanceName: utils.ToGoIdentifier(tableMetaData.Name),
+		InstanceName: dbidentifier.ToGoIdentifier(tableMetaData.Name),
-		TypeName:     utils.ToGoIdentifier(tableMetaData.Name) + "Table",
+		TypeName:     dbidentifier.ToGoIdentifier(tableMetaData.Name) + "Table",
 		Column:       DefaultTableSQLBuilderColumn,
 	}
 }
@@ -127,7 +127,7 @@ type TableSQLBuilderColumn struct {
 // DefaultTableSQLBuilderColumn returns default implementation of TableSQLBuilderColumn
 func DefaultTableSQLBuilderColumn(columnMetaData metadata.Column) TableSQLBuilderColumn {
 	return TableSQLBuilderColumn{
-		Name: utils.ToGoIdentifier(columnMetaData.Name),
+		Name: dbidentifier.ToGoIdentifier(columnMetaData.Name),
 		Type: getSqlBuilderColumnType(columnMetaData),
 	}
 }
@@ -185,8 +185,8 @@ type EnumSQLBuilder struct {
 func DefaultEnumSQLBuilder(enumMetaData metadata.Enum) EnumSQLBuilder {
 	return EnumSQLBuilder{
 		Path:         "/enum",
-		FileName:     utils.ToGoFileName(enumMetaData.Name),
+		FileName:     dbidentifier.ToGoFileName(enumMetaData.Name),
-		InstanceName: utils.ToGoIdentifier(enumMetaData.Name),
+		InstanceName: dbidentifier.ToGoIdentifier(enumMetaData.Name),
 		ValueName: func(enumValue string) string {
 			return defaultEnumValueName(enumMetaData.Name, enumValue)
 		},
@@ -217,9 +217,9 @@ func (e EnumSQLBuilder) UseInstanceName(name string) EnumSQLBuilder {
 }
 
 func defaultEnumValueName(enumName, enumValue string) string {
-	enumValueName := utils.ToGoIdentifier(enumValue)
+	enumValueName := dbidentifier.ToGoIdentifier(enumValue)
 	if !unicode.IsLetter([]rune(enumValueName)[0]) {
-		return utils.ToGoIdentifier(enumName) + enumValueName
+		return dbidentifier.ToGoIdentifier(enumName) + enumValueName
 	}
 
 	return enumValueName

internal/jet/clause.go

@@ -1,8 +1,6 @@
 package jet
 
-import (
+import "github.com/go-jet/jet/v2/internal/utils/is"
-	"github.com/go-jet/jet/v2/internal/utils"
-)
 
 // Clause interface
 type Clause interface {
@@ -322,7 +320,7 @@ func (u *ClauseUpdate) Serialize(statementType StatementType, out *SQLBuilder, o
 	out.WriteString("UPDATE")
 	u.OptimizerHints.Serialize(statementType, out, options...)
 
-	if utils.IsNil(u.Table) {
+	if is.Nil(u.Table) {
 		panic("jet: table to update is nil")
 	}
 
@@ -387,7 +385,7 @@ func (i *ClauseInsert) GetColumns() []Column {
 
 // Serialize serializes clause into SQLBuilder
 func (i *ClauseInsert) Serialize(statementType StatementType, out *SQLBuilder, options ...SerializeOption) {
-	if utils.IsNil(i.Table) {
+	if is.Nil(i.Table) {
 		panic("jet: table is nil for INSERT clause")
 	}
 

internal/jet/sql_builder.go

@@ -5,7 +5,7 @@ import (
 	"database/sql/driver"
 	"fmt"
 	"github.com/go-jet/jet/v2/internal/3rdparty/pq"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/is"
 	"github.com/google/uuid"
 	"reflect"
 	"sort"
@@ -206,7 +206,7 @@ func (s *SQLBuilder) insertRawQuery(raw string, namedArg map[string]interface{})
 }
 
 func argToString(value interface{}) string {
-	if utils.IsNil(value) {
+	if is.Nil(value) {
 		return "NULL"
 	}
 

internal/jet/table.go

@@ -1,8 +1,6 @@
 package jet
 
-import (
+import "github.com/go-jet/jet/v2/internal/utils/is"
-	"github.com/go-jet/jet/v2/internal/utils"
-)
 
 // SerializerTable interface
 type SerializerTable interface {
@@ -158,7 +156,7 @@ func (t *joinTableImpl) serialize(statement StatementType, out *SQLBuilder, opti
 		panic("jet: Join table is nil. ")
 	}
 
-	if utils.IsNil(t.lhs) {
+	if is.Nil(t.lhs) {
 		panic("jet: left hand side of join operation is nil table")
 	}
 
@@ -179,7 +177,7 @@ func (t *joinTableImpl) serialize(statement StatementType, out *SQLBuilder, opti
 		out.WriteString("CROSS JOIN")
 	}
 
-	if utils.IsNil(t.rhs) {
+	if is.Nil(t.rhs) {
 		panic("jet: right hand side of join operation is nil table")
 	}
 

internal/jet/utils.go

@@ -1,7 +1,8 @@
 package jet
 
 import (
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/dbidentifier"
+	"github.com/go-jet/jet/v2/internal/utils/must"
 	"reflect"
 	"strings"
 )
@@ -150,11 +151,11 @@ func UnwindRowFromModel(columns []Column, data interface{}) []Serializer {
 
 	row := []Serializer{}
 
-	utils.ValueMustBe(structValue, reflect.Struct, "jet: data has to be a struct")
+	must.ValueBeOfTypeKind(structValue, reflect.Struct, "jet: data has to be a struct")
 
 	for _, column := range columns {
 		columnName := column.Name()
-		structFieldName := utils.ToGoIdentifier(columnName)
+		structFieldName := dbidentifier.ToGoIdentifier(columnName)
 
 		structField := structValue.FieldByName(structFieldName)
 
@@ -179,7 +180,7 @@ func UnwindRowFromModel(columns []Column, data interface{}) []Serializer {
 // UnwindRowsFromModels func
 func UnwindRowsFromModels(columns []Column, data interface{}) [][]Serializer {
 	sliceValue := reflect.Indirect(reflect.ValueOf(data))
-	utils.ValueMustBe(sliceValue, reflect.Slice, "jet: data has to be a slice.")
+	must.ValueBeOfTypeKind(sliceValue, reflect.Slice, "jet: data has to be a slice.")
 
 	rows := [][]Serializer{}
 

internal/utils/datetime/duration.go

@@ -0,0 +1,22 @@
+package datetime
+
+import "time"
+
+// ExtractTimeComponents extracts number of days, hours, minutes, seconds, microseconds from duration
+func ExtractTimeComponents(duration time.Duration) (days, hours, minutes, seconds, microseconds int64) {
+	days = int64(duration / (24 * time.Hour))
+	reminder := duration % (24 * time.Hour)
+
+	hours = int64(reminder / time.Hour)
+	reminder = reminder % time.Hour
+
+	minutes = int64(reminder / time.Minute)
+	reminder = reminder % time.Minute
+
+	seconds = int64(reminder / time.Second)
+	reminder = reminder % time.Second
+
+	microseconds = int64(reminder / time.Microsecond)
+
+	return
+}

internal/utils/dbidentifier/dbidentifier.go

@@ -0,0 +1,24 @@
+package dbidentifier
+
+import (
+	"github.com/go-jet/jet/v2/internal/3rdparty/snaker"
+	"strings"
+)
+
+// ToGoIdentifier converts database identifier to Go identifier.
+func ToGoIdentifier(databaseIdentifier string) string {
+	return snaker.SnakeToCamel(replaceInvalidChars(databaseIdentifier))
+}
+
+// ToGoFileName converts database identifier to Go file name.
+func ToGoFileName(databaseIdentifier string) string {
+	return strings.ToLower(replaceInvalidChars(databaseIdentifier))
+}
+
+func replaceInvalidChars(str string) string {
+	str = strings.Replace(str, " ", "_", -1)
+	str = strings.Replace(str, "-", "_", -1)
+	str = strings.Replace(str, ".", "_", -1)
+
+	return str
+}

internal/utils/dbidentifier/dbidentifier_test.go

@@ -1,7 +1,6 @@
-package utils
+package dbidentifier
 
 import (
-	"fmt"
 	"github.com/stretchr/testify/require"
 	"testing"
 )
@@ -24,27 +23,3 @@ func TestToGoIdentifier(t *testing.T) {
 	require.Equal(t, ToGoIdentifier("My Table"), "MyTable")
 	require.Equal(t, ToGoIdentifier("My-Table"), "MyTable")
 }
-
-func TestErrorCatchErr(t *testing.T) {
-	var err error
-
-	func() {
-		defer ErrorCatch(&err)
-
-		panic(fmt.Errorf("newError"))
-	}()
-
-	require.Error(t, err, "newError")
-}
-
-func TestErrorCatchNonErr(t *testing.T) {
-	var err error
-
-	func() {
-		defer ErrorCatch(&err)
-
-		panic(11)
-	}()
-
-	require.Error(t, err, "11")
-}

internal/utils/filesys/filesys.go

@@ -0,0 +1,85 @@
+package filesys
+
+import (
+	"fmt"
+	"go/format"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// FormatAndSaveGoFile saves go file at folder dir, with name fileName and contents text.
+func FormatAndSaveGoFile(dirPath, fileName string, text []byte) error {
+	newGoFilePath := filepath.Join(dirPath, fileName)
+
+	if !strings.HasSuffix(newGoFilePath, ".go") {
+		newGoFilePath += ".go"
+	}
+
+	file, err := os.Create(newGoFilePath)
+
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	p, err := format.Source(text)
+
+	// if there is a format error we will write unformulated text for debug purposes
+	if err != nil {
+		file.Write(text)
+		return fmt.Errorf("failed to format '%s', check '%s' for syntax errors: %w", fileName, newGoFilePath, err)
+	}
+
+	_, err = file.Write(p)
+	if err != nil {
+		return fmt.Errorf("failed to save '%s' file: %w", newGoFilePath, err)
+	}
+
+	return nil
+}
+
+// EnsureDirPathExist ensures dir path exists. If path does not exist, creates new path.
+func EnsureDirPathExist(dirPath string) error {
+	if _, err := os.Stat(dirPath); os.IsNotExist(err) {
+		err := os.MkdirAll(dirPath, os.ModePerm)
+
+		if err != nil {
+			return fmt.Errorf("can't create directory - %s: %w", dirPath, err)
+		}
+	}
+
+	return nil
+}
+
+// RemoveDir deletes everything at folder dir.
+func RemoveDir(dir string) error {
+	exist, err := DirExists(dir)
+
+	if err != nil {
+		return err
+	}
+
+	if exist {
+		err := os.RemoveAll(dir)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// DirExists checks if folder at path exist.
+func DirExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return true, err
+}

internal/utils/is/is.go

@@ -0,0 +1,8 @@
+package is
+
+import "reflect"
+
+// Nil check if v is nil
+func Nil(v interface{}) bool {
+	return v == nil || (reflect.ValueOf(v).Kind() == reflect.Ptr && reflect.ValueOf(v).IsNil())
+}

internal/utils/must/must.go

@@ -0,0 +1,41 @@
+package must
+
+import (
+	"github.com/go-jet/jet/v2/internal/utils/is"
+	"reflect"
+)
+
+// BeTrue panics when condition is false
+func BeTrue(condition bool, errorStr string) {
+	if !condition {
+		panic(errorStr)
+	}
+}
+
+// BeTypeKind panics with errorStr error, if v interface is not of reflect kind
+func BeTypeKind(v interface{}, kind reflect.Kind, errorStr string) {
+	if reflect.TypeOf(v).Kind() != kind {
+		panic(errorStr)
+	}
+}
+
+// ValueBeOfTypeKind panics with errorStr error, if v value is not of reflect kind
+func ValueBeOfTypeKind(v reflect.Value, kind reflect.Kind, errorStr string) {
+	if v.Kind() != kind {
+		panic(errorStr)
+	}
+}
+
+// TypeBeOfKind panics with errorStr error, if v type is not of reflect kind
+func TypeBeOfKind(v reflect.Type, kind reflect.Kind, errorStr string) {
+	if v.Kind() != kind {
+		panic(errorStr)
+	}
+}
+
+// BeInitializedPtr panics with errorStr if val interface is nil
+func BeInitializedPtr(val interface{}, errorStr string) {
+	if is.Nil(val) {
+		panic(errorStr)
+	}
+}

internal/utils/strslice/strslice.go

@@ -0,0 +1,12 @@
+package strslice
+
+// Contains checks if slice of strings contains a string
+func Contains(strings []string, contains string) bool {
+	for _, str := range strings {
+		if str == contains {
+			return true
+		}
+	}
+
+	return false
+}

internal/utils/utils.go

@@ -1,203 +0,0 @@
-package utils
-
-import (
-	"database/sql"
-	"fmt"
-	"github.com/go-jet/jet/v2/internal/3rdparty/snaker"
-	"go/format"
-	"os"
-	"path/filepath"
-	"reflect"
-	"strings"
-	"time"
-)
-
-// ToGoIdentifier converts database to Go identifier.
-func ToGoIdentifier(databaseIdentifier string) string {
-	return snaker.SnakeToCamel(replaceInvalidChars(databaseIdentifier))
-}
-
-// ToGoFileName converts database identifier to Go file name.
-func ToGoFileName(databaseIdentifier string) string {
-	return strings.ToLower(replaceInvalidChars(databaseIdentifier))
-}
-
-// SaveGoFile saves go file at folder dir, with name fileName and contents text.
-func SaveGoFile(dirPath, fileName string, text []byte) error {
-	newGoFilePath := filepath.Join(dirPath, fileName)
-
-	if !strings.HasSuffix(newGoFilePath, ".go") {
-		newGoFilePath += ".go"
-	}
-
-	file, err := os.Create(newGoFilePath)
-
-	if err != nil {
-		return err
-	}
-
-	defer file.Close()
-
-	p, err := format.Source(text)
-
-	// if there is a format error we will write unformulated text for debug purposes
-	if err != nil {
-		file.Write(text)
-		return fmt.Errorf("failed to format '%s', check '%s' for syntax errors: %w", fileName, newGoFilePath, err)
-	}
-
-	_, err = file.Write(p)
-	if err != nil {
-		return fmt.Errorf("failed to save '%s' file: %w", newGoFilePath, err)
-	}
-
-	return nil
-}
-
-// EnsureDirPath ensures dir path exists. If path does not exist, creates new path.
-func EnsureDirPath(dirPath string) error {
-	if _, err := os.Stat(dirPath); os.IsNotExist(err) {
-		err := os.MkdirAll(dirPath, os.ModePerm)
-
-		if err != nil {
-			return fmt.Errorf("can't create directory - %s: %w", dirPath, err)
-		}
-	}
-
-	return nil
-}
-
-// CleanUpGeneratedFiles deletes everything at folder dir.
-func CleanUpGeneratedFiles(dir string) error {
-	exist, err := DirExists(dir)
-
-	if err != nil {
-		return err
-	}
-
-	if exist {
-		err := os.RemoveAll(dir)
-
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-// DBClose closes non nil db connection
-func DBClose(db *sql.DB) {
-	if db == nil {
-		return
-	}
-
-	db.Close()
-}
-
-// DirExists checks if folder at path exist.
-func DirExists(path string) (bool, error) {
-	_, err := os.Stat(path)
-	if err == nil {
-		return true, nil
-	}
-	if os.IsNotExist(err) {
-		return false, nil
-	}
-	return true, err
-}
-
-func replaceInvalidChars(str string) string {
-	str = strings.Replace(str, " ", "_", -1)
-	str = strings.Replace(str, "-", "_", -1)
-	str = strings.Replace(str, ".", "_", -1)
-
-	return str
-}
-
-// IsNil check if v is nil
-func IsNil(v interface{}) bool {
-	return v == nil || (reflect.ValueOf(v).Kind() == reflect.Ptr && reflect.ValueOf(v).IsNil())
-}
-
-// MustBeTrue panics when condition is false
-func MustBeTrue(condition bool, errorStr string) {
-	if !condition {
-		panic(errorStr)
-	}
-}
-
-// MustBe panics with errorStr error, if v interface is not of reflect kind
-func MustBe(v interface{}, kind reflect.Kind, errorStr string) {
-	if reflect.TypeOf(v).Kind() != kind {
-		panic(errorStr)
-	}
-}
-
-// ValueMustBe panics with errorStr error, if v value is not of reflect kind
-func ValueMustBe(v reflect.Value, kind reflect.Kind, errorStr string) {
-	if v.Kind() != kind {
-		panic(errorStr)
-	}
-}
-
-// TypeMustBe panics with errorStr error, if v type is not of reflect kind
-func TypeMustBe(v reflect.Type, kind reflect.Kind, errorStr string) {
-	if v.Kind() != kind {
-		panic(errorStr)
-	}
-}
-
-// MustBeInitializedPtr panics with errorStr if val interface is nil
-func MustBeInitializedPtr(val interface{}, errorStr string) {
-	if IsNil(val) {
-		panic(errorStr)
-	}
-}
-
-// ErrorCatch is used in defer to recover from panics and to set err
-func ErrorCatch(err *error) {
-	recovered := recover()
-
-	if recovered == nil {
-		return
-	}
-
-	recoveredErr, isError := recovered.(error)
-
-	if isError {
-		*err = recoveredErr
-	} else {
-		*err = fmt.Errorf("%v", recovered)
-	}
-}
-
-// StringSliceContains checks if slice of strings contains a string
-func StringSliceContains(strings []string, contains string) bool {
-	for _, str := range strings {
-		if str == contains {
-			return true
-		}
-	}
-
-	return false
-}
-
-// ExtractDateTimeComponents extracts number of days, hours, minutes, seconds, microseconds from duration
-func ExtractDateTimeComponents(duration time.Duration) (days, hours, minutes, seconds, microseconds int64) {
-	days = int64(duration / (24 * time.Hour))
-	reminder := duration % (24 * time.Hour)
-
-	hours = int64(reminder / time.Hour)
-	reminder = reminder % time.Hour
-
-	minutes = int64(reminder / time.Minute)
-	reminder = reminder % time.Minute
-
-	seconds = int64(reminder / time.Second)
-	reminder = reminder % time.Second
-
-	microseconds = int64(reminder / time.Microsecond)
-
-	return
-}

mysql/interval.go

@@ -2,11 +2,11 @@ package mysql
 
 import (
 	"fmt"
+	"github.com/go-jet/jet/v2/internal/utils/datetime"
 	"regexp"
 	"time"
 
 	"github.com/go-jet/jet/v2/internal/jet"
-	"github.com/go-jet/jet/v2/internal/utils"
 )
 
 type unitType string
@@ -112,7 +112,7 @@ func INTERVALd(duration time.Duration) Interval {
 		duration = -duration
 	}
 
-	days, hours, minutes, sec, microsec := utils.ExtractDateTimeComponents(duration)
+	days, hours, minutes, sec, microsec := datetime.ExtractTimeComponents(duration)
 
 	if days != 0 {
 		switch {

postgres/interval_expression.go

@@ -3,7 +3,7 @@ package postgres
 import (
 	"fmt"
 	"github.com/go-jet/jet/v2/internal/jet"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/datetime"
 	"strconv"
 	"strings"
 	"time"
@@ -148,9 +148,9 @@ func INTERVAL(quantityAndUnit ...quantityAndUnit) IntervalExpression {
 
 // INTERVALd creates interval expression from time.Duration
 func INTERVALd(duration time.Duration) IntervalExpression {
-	days, hours, minutes, seconds, microseconds := utils.ExtractDateTimeComponents(duration)
+	days, hours, minutes, seconds, microseconds := datetime.ExtractTimeComponents(duration)
 
-	quantityAndUnits := []quantityAndUnit{}
+	var quantityAndUnits []quantityAndUnit
 
 	if days > 0 {
 		quantityAndUnits = append(quantityAndUnits, quantityAndUnit(days))

qrm/qrm.go

@@ -5,9 +5,8 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"github.com/go-jet/jet/v2/internal/utils/must"
 	"reflect"
-
-	"github.com/go-jet/jet/v2/internal/utils"
 )
 
 // ErrNoRows is returned by Query when query result set is empty
@@ -19,9 +18,9 @@ var ErrNoRows = errors.New("qrm: no rows in result set")
 // If destination is pointer to struct and query result set is empty, method returns qrm.ErrNoRows.
 func Query(ctx context.Context, db Queryable, query string, args []interface{}, destPtr interface{}) (rowsProcessed int64, err error) {
 
-	utils.MustBeInitializedPtr(db, "jet: db is nil")
+	must.BeInitializedPtr(db, "jet: db is nil")
-	utils.MustBeInitializedPtr(destPtr, "jet: destination is nil")
+	must.BeInitializedPtr(destPtr, "jet: destination is nil")
-	utils.MustBe(destPtr, reflect.Ptr, "jet: destination has to be a pointer to slice or pointer to struct")
+	must.BeTypeKind(destPtr, reflect.Ptr, "jet: destination has to be a pointer to slice or pointer to struct")
 
 	destinationPtrType := reflect.TypeOf(destPtr)
 
@@ -64,8 +63,8 @@ func Query(ctx context.Context, db Queryable, query string, args []interface{},
 
 // ScanOneRowToDest will scan one row into struct destination
 func ScanOneRowToDest(scanContext *ScanContext, rows *sql.Rows, destPtr interface{}) error {
-	utils.MustBeInitializedPtr(destPtr, "jet: destination is nil")
+	must.BeInitializedPtr(destPtr, "jet: destination is nil")
-	utils.MustBe(destPtr, reflect.Ptr, "jet: destination has to be a pointer to slice or pointer to struct")
+	must.BeTypeKind(destPtr, reflect.Ptr, "jet: destination has to be a pointer to slice or pointer to struct")
 
 	if len(scanContext.row) == 0 {
 		return errors.New("empty row slice")
@@ -149,7 +148,7 @@ func mapRowToSlice(
 		return
 	}
 
-	utils.TypeMustBe(sliceElemType, reflect.Struct, "jet: unsupported slice element type"+fieldToString(field))
+	must.TypeBeOfKind(sliceElemType, reflect.Struct, "jet: unsupported slice element type"+fieldToString(field))
 
 	structGroupKey := scanContext.getGroupKey(sliceElemType, field)
 
@@ -324,7 +323,7 @@ func mapRowToDestinationPtr(
 	destPtrValue reflect.Value,
 	structField *reflect.StructField) (updated bool, err error) {
 
-	utils.ValueMustBe(destPtrValue, reflect.Ptr, "jet: internal error. Destination is not pointer.")
+	must.ValueBeOfTypeKind(destPtrValue, reflect.Ptr, "jet: internal error. Destination is not pointer.")
 
 	destValueKind := destPtrValue.Elem().Kind()
 

qrm/utill.go

@@ -3,7 +3,8 @@ package qrm
 import (
 	"database/sql"
 	"fmt"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/must"
+	"github.com/go-jet/jet/v2/internal/utils/strslice"
 	"github.com/go-jet/jet/v2/qrm/internal"
 	"github.com/google/uuid"
 	"reflect"
@@ -50,7 +51,7 @@ func getSliceElemPtrAt(slicePtrValue reflect.Value, index int) reflect.Value {
 }
 
 func appendElemToSlice(slicePtrValue reflect.Value, objPtrValue reflect.Value) error {
-	utils.MustBeTrue(!slicePtrValue.IsNil(), "jet: internal, slice is nil")
+	must.BeTrue(!slicePtrValue.IsNil(), "jet: internal, slice is nil")
 
 	sliceValue := slicePtrValue.Elem()
 	sliceElemType := sliceValue.Type().Elem()
@@ -306,7 +307,7 @@ func setZeroValue(value reflect.Value) {
 
 func isPrimaryKey(field reflect.StructField, primaryKeyOverwrites []string) bool {
 	if len(primaryKeyOverwrites) > 0 {
-		return utils.StringSliceContains(primaryKeyOverwrites, field.Name)
+		return strslice.Contains(primaryKeyOverwrites, field.Name)
 	}
 
 	sqlTag := field.Tag.Get("sql")

tests/mysql/generator_template_test.go

@@ -7,7 +7,7 @@ import (
 	mysql2 "github.com/go-jet/jet/v2/generator/mysql"
 	"github.com/go-jet/jet/v2/generator/template"
 	"github.com/go-jet/jet/v2/internal/3rdparty/snaker"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/dbidentifier"
 	postgres2 "github.com/go-jet/jet/v2/postgres"
 	"github.com/go-jet/jet/v2/tests/dbconfig"
 	file2 "github.com/go-jet/jet/v2/tests/internal/utils/file"
@@ -157,17 +157,17 @@ func TestGeneratorTemplate_Model_RenameFilesAndTypes(t *testing.T) {
 						UseTable(func(table metadata.Table) template.TableModel {
 							return template.DefaultTableModel(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name).
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "Table")
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "Table")
 						}).
 						UseView(func(table metadata.Table) template.ViewModel {
 							return template.DefaultViewModel(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name + "_view").
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "View")
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "View")
 						}).
 						UseEnum(func(enumMetaData metadata.Enum) template.EnumModel {
 							return template.DefaultEnumModel(enumMetaData).
 								UseFileName(enumMetaData.Name + "_enum").
-								UseTypeName(utils.ToGoIdentifier(enumMetaData.Name) + "Enum")
+								UseTypeName(dbidentifier.ToGoIdentifier(enumMetaData.Name) + "Enum")
 						}),
 					)
 			}),
@@ -256,19 +256,19 @@ func TestGeneratorTemplate_SQLBuilder_ChangeTypeAndFileName(t *testing.T) {
 						UseTable(func(table metadata.Table) template.TableSQLBuilder {
 							return template.DefaultTableSQLBuilder(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name + "_table").
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "TableSQLBuilder").
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "TableSQLBuilder").
-								UseInstanceName("T_" + utils.ToGoIdentifier(table.Name))
+								UseInstanceName("T_" + dbidentifier.ToGoIdentifier(table.Name))
 						}).
 						UseView(func(table metadata.Table) template.ViewSQLBuilder {
 							return template.DefaultViewSQLBuilder(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name + "_view").
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "ViewSQLBuilder").
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "ViewSQLBuilder").
-								UseInstanceName("V_" + utils.ToGoIdentifier(table.Name))
+								UseInstanceName("V_" + dbidentifier.ToGoIdentifier(table.Name))
 						}).
 						UseEnum(func(enum metadata.Enum) template.EnumSQLBuilder {
 							return template.DefaultEnumSQLBuilder(enum).
 								UseFileName(schemaMetaData.Name + "_" + enum.Name + "_enum").
-								UseInstanceName(utils.ToGoIdentifier(enum.Name) + "EnumSQLBuilder")
+								UseInstanceName(dbidentifier.ToGoIdentifier(enum.Name) + "EnumSQLBuilder")
 						}),
 					)
 			}),

tests/postgres/generator_template_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/go-jet/jet/v2/generator/template"
 	"github.com/go-jet/jet/v2/internal/3rdparty/snaker"
 	"github.com/go-jet/jet/v2/internal/testutils"
-	"github.com/go-jet/jet/v2/internal/utils"
+	"github.com/go-jet/jet/v2/internal/utils/dbidentifier"
 	postgres2 "github.com/go-jet/jet/v2/postgres"
 	"github.com/go-jet/jet/v2/tests/dbconfig"
 	file2 "github.com/go-jet/jet/v2/tests/internal/utils/file"
@@ -144,17 +144,17 @@ func TestGeneratorTemplate_Model_RenameFilesAndTypes(t *testing.T) {
 						UseTable(func(table metadata.Table) template.TableModel {
 							return template.DefaultTableModel(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name).
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "Table")
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "Table")
 						}).
 						UseView(func(table metadata.Table) template.ViewModel {
 							return template.DefaultViewModel(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name + "_view").
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "View")
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "View")
 						}).
 						UseEnum(func(enumMetaData metadata.Enum) template.EnumModel {
 							return template.DefaultEnumModel(enumMetaData).
 								UseFileName(enumMetaData.Name + "_enum").
-								UseTypeName(utils.ToGoIdentifier(enumMetaData.Name) + "Enum")
+								UseTypeName(dbidentifier.ToGoIdentifier(enumMetaData.Name) + "Enum")
 						}),
 					)
 			}),
@@ -280,19 +280,19 @@ func TestGeneratorTemplate_SQLBuilder_ChangeTypeAndFileName(t *testing.T) {
 						UseTable(func(table metadata.Table) template.TableSQLBuilder {
 							return template.DefaultTableSQLBuilder(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name + "_table").
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "TableSQLBuilder").
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "TableSQLBuilder").
-								UseInstanceName("T_" + utils.ToGoIdentifier(table.Name))
+								UseInstanceName("T_" + dbidentifier.ToGoIdentifier(table.Name))
 						}).
 						UseView(func(table metadata.Table) template.ViewSQLBuilder {
 							return template.DefaultViewSQLBuilder(table).
 								UseFileName(schemaMetaData.Name + "_" + table.Name + "_view").
-								UseTypeName(utils.ToGoIdentifier(table.Name) + "ViewSQLBuilder").
+								UseTypeName(dbidentifier.ToGoIdentifier(table.Name) + "ViewSQLBuilder").
-								UseInstanceName("V_" + utils.ToGoIdentifier(table.Name))
+								UseInstanceName("V_" + dbidentifier.ToGoIdentifier(table.Name))
 						}).
 						UseEnum(func(enum metadata.Enum) template.EnumSQLBuilder {
 							return template.DefaultEnumSQLBuilder(enum).
 								UseFileName(schemaMetaData.Name + "_" + enum.Name + "_enum").
-								UseInstanceName(utils.ToGoIdentifier(enum.Name) + "EnumSQLBuilder")
+								UseInstanceName(dbidentifier.ToGoIdentifier(enum.Name) + "EnumSQLBuilder")
 						}),
 					)
 			}),