Refactor random number generation and add version-specific implementations

Removed error handling from `randNum` in `random_test.go` and introduced new `randNum` implementations for different Go versions (1.19, 1.20-1.21, 1.22+). This ensures compatibility with different versions of Go and utilizes the appropriate version-specific random number generation methods. We are using math/rand instead crypto/rand. For our needs this should be sufficient.
This commit is contained in:
Winni Neessen 2024-09-20 20:30:23 +02:00
parent af9915e4e7
commit 19330fc108
Signed by: wneessen
GPG key ID: 385AC9889632126E
5 changed files with 65 additions and 29 deletions

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@ -7,8 +7,6 @@ package mail
import (
"crypto/rand"
"encoding/binary"
"fmt"
"math/big"
"strings"
)
@ -52,23 +50,3 @@ func randomStringSecure(length int) (string, error) {
return randString.String(), nil
}
// randNum returns a random number with a maximum value of length
func randNum(length int) (int, error) {
if length <= 0 {
return 0, fmt.Errorf("provided number is <= 0: %d", length)
}
length64 := big.NewInt(int64(length))
if !length64.IsUint64() {
return 0, fmt.Errorf("big.NewInt() generation returned negative value: %d", length64)
}
randNum64, err := rand.Int(rand.Reader, length64)
if err != nil {
return 0, err
}
randomNum := int(randNum64.Int64())
if randomNum < 0 {
return 0, fmt.Errorf("generated random number does not fit as int64: %d", randNum64)
}
return randomNum, nil
}

22
random_119.go Normal file
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@ -0,0 +1,22 @@
// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
//
// SPDX-License-Identifier: MIT
//go:build go1.19 && !go1.20
// +build go1.19,!go1.20
package mail
import (
"math/rand"
"time"
)
// randNum returns a random number with a maximum value of length
func randNum(maxval int) int {
if maxval <= 0 {
return 0
}
rand.Seed(time.Now().UnixNano())
return rand.Intn(maxval)
}

20
random_121.go Normal file
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@ -0,0 +1,20 @@
// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
//
// SPDX-License-Identifier: MIT
//go:build go1.20 && !go1.22
// +build go1.20,!go1.22
package mail
import (
"math/rand"
)
// randNum returns a random number with a maximum value of length
func randNum(maxval int) int {
if maxval <= 0 {
return 0
}
return rand.Intn(maxval)
}

22
random_122.go Normal file
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@ -0,0 +1,22 @@
// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
//
// SPDX-License-Identifier: MIT
//go:build go1.22
// +build go1.22
package mail
import (
"math/rand/v2"
)
// randNum returns a random number with a maximum value of maxval.
// go-mail compiled with Go 1.22+ will make use of the novel math/rand/v2 interface
// Older versions of Go will use math/rand
func randNum(maxval int) int {
if maxval <= 0 {
return 0
}
return rand.IntN(maxval)
}

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@ -55,13 +55,7 @@ func TestRandomNum(t *testing.T) {
for _, tc := range tt {
t.Run(tc.testName, func(t *testing.T) {
rn, err := randNum(tc.max)
if err != nil {
t.Errorf("random number generation failed: %s", err)
}
if rn < 0 {
t.Errorf("random number generation failed: %d is smaller than zero", rn)
}
rn := randNum(tc.max)
if rn > tc.max {
t.Errorf("random number generation failed: %d is bigger than given value %d", rn, tc.max)
}