refactor: replace docker-gen functions with sprig identical functions

(1/2)

Author: buchdag

internal/template/functions.go

@@ -1,18 +1,18 @@
 package template
 
 import (
-	"bytes"
-	"crypto/sha1"
-	"encoding/json"
 	"fmt"
-	"io"
 	"log"
 	"os"
 	"reflect"
 	"regexp"
 	"strings"
+
+	"github.com/Masterminds/sprig/v3"
 )
 
+var sprigFuncMap = sprig.TxtFuncMap()
+
 func keys(input interface{}) (interface{}, error) {
 	if input == nil {
 		return nil, nil
@@ -82,26 +82,15 @@ func contains(input interface{}, key interface{}) bool {
 }
 
 func hashSha1(input string) string {
-	h := sha1.New()
-	io.WriteString(h, input)
-	return fmt.Sprintf("%x", h.Sum(nil))
+	return sprigFuncMap["sha1sum"].(func(string) string)(input)
 }
 
 func marshalJson(input interface{}) (string, error) {
-	var buf bytes.Buffer
-	enc := json.NewEncoder(&buf)
-	if err := enc.Encode(input); err != nil {
-		return "", err
-	}
-	return strings.TrimSuffix(buf.String(), "\n"), nil
+	return sprigFuncMap["mustToJson"].(func(interface{}) (string, error))(input)
 }
 
 func unmarshalJson(input string) (interface{}, error) {
-	var v interface{}
-	if err := json.Unmarshal([]byte(input), &v); err != nil {
-		return nil, err
-	}
-	return v, nil
+	return sprigFuncMap["mustFromJson"].(func(string) (interface{}, error))(input)
 }
 
 // arrayClosest find the longest matching substring in values
@@ -132,32 +121,17 @@ func dirList(path string) ([]string, error) {
 
 // coalesce returns the first non nil argument
 func coalesce(input ...interface{}) interface{} {
-	for _, v := range input {
-		if v != nil {
-			return v
-		}
-	}
-	return nil
+	return sprigFuncMap["coalesce"].(func(...interface{}) interface{})(input...)
 }
 
 // trimPrefix returns a string without the prefix, if present
 func trimPrefix(prefix, s string) string {
-	return strings.TrimPrefix(s, prefix)
+	return sprigFuncMap["trimPrefix"].(func(string, string) string)(prefix, s)
 }
 
 // trimSuffix returns a string without the suffix, if present
 func trimSuffix(suffix, s string) string {
-	return strings.TrimSuffix(s, suffix)
-}
-
-// toLower return the string in lower case
-func toLower(s string) string {
-	return strings.ToLower(s)
-}
-
-// toUpper return the string in upper case
-func toUpper(s string) string {
-	return strings.ToUpper(s)
+	return sprigFuncMap["trimSuffix"].(func(string, string) string)(suffix, s)
 }
 
 // when returns the trueValue when the condition is true and the falseValue otherwise

internal/template/functions_test.go

@@ -150,18 +150,6 @@ func TestTrimSuffix(t *testing.T) {
 	}
 }
 
-func TestToLower(t *testing.T) {
-	const str = ".RaNd0m StrinG_"
-	const lowered = ".rand0m string_"
-	assert.Equal(t, lowered, toLower(str), "Unexpected value from toLower()")
-}
-
-func TestToUpper(t *testing.T) {
-	const str = ".RaNd0m StrinG_"
-	const uppered = ".RAND0M STRING_"
-	assert.Equal(t, uppered, toUpper(str), "Unexpected value from toUpper()")
-}
-
 func TestSha1(t *testing.T) {
 	sum := hashSha1("/path")
 	if sum != "4f26609ad3f5185faaa9edf1e93aa131e2131352" {

internal/template/template.go

@@ -59,7 +59,6 @@ func newTemplate(name string) *template.Template {
 	}
 	tmpl.Funcs(sprig.TxtFuncMap()).Funcs(template.FuncMap{
 		"closest":                 arrayClosest,
-		"coalesce":                coalesce,
 		"comment":                 comment,
 		"contains":                contains,
 		"dir":                     dirList,
@@ -71,19 +70,16 @@ func newTemplate(name string) *template.Template {
 		"groupByMulti":            groupByMulti,
 		"groupByLabel":            groupByLabel,
 		"groupByLabelWithDefault": groupByLabelWithDefault,
-		"json":                    marshalJson,
 		"include":                 include,
 		"intersect":               intersect,
 		"keys":                    keys,
 		"replace":                 strings.Replace,
 		"parseBool":               strconv.ParseBool,
-		"parseJson":               unmarshalJson,
 		"fromYaml":                fromYaml,
 		"toYaml":                  toYaml,
 		"mustFromYaml":            mustFromYaml,
 		"mustToYaml":              mustToYaml,
 		"queryEscape":             url.QueryEscape,
-		"sha1":                    hashSha1,
 		"split":                   strings.Split,
 		"splitN":                  strings.SplitN,
 		"sortStringsAsc":          sortStringsAsc,
@@ -92,8 +88,8 @@ func newTemplate(name string) *template.Template {
 		"sortObjectsByKeysDesc":   sortObjectsByKeysDesc,
 		"trimPrefix":              trimPrefix,
 		"trimSuffix":              trimSuffix,
-		"toLower":                 toLower,
-		"toUpper":                 toUpper,
+		"toLower":                 strings.ToLower,
+		"toUpper":                 strings.ToUpper,
 		"when":                    when,
 		"where":                   where,
 		"whereNot":                whereNot,
@@ -104,6 +100,12 @@ func newTemplate(name string) *template.Template {
 		"whereLabelExists":        whereLabelExists,
 		"whereLabelDoesNotExist":  whereLabelDoesNotExist,
 		"whereLabelValueMatches":  whereLabelValueMatches,
+	}).Funcs(template.FuncMap{
+		// docker-gen template function replaced by their Sprig clone
+		"coalesce":  coalesce,
+		"json":      marshalJson,
+		"parseJson": unmarshalJson,
+		"sha1":      hashSha1,
 	})
 	return tmpl
 }