Skip to content

[test-improver] Improve tests for strutil.RandomHex #3636

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
lpcox merged 1 commit into from
Apr 14, 2026
Merged

[test-improver] Improve tests for strutil.RandomHex #3636

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
46 changes: 43 additions & 3 deletions internal/strutil/random_hex_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
package strutil

import (
"encoding/hex"
"testing"

"github.com/stretchr/testify/assert"
Expand All @@ -12,7 +13,18 @@ func TestRandomHex(t *testing.T) {
name string
n int
wantLen int
wantErr bool
}{
{
name: "zero bytes produces empty string",
n: 0,
wantLen: 0,
},
{
name: "1 byte produces 2 hex chars",
n: 1,
wantLen: 2,
},
{
name: "16 bytes produces 32 hex chars",
n: 16,
Expand All @@ -24,21 +36,49 @@ func TestRandomHex(t *testing.T) {
wantLen: 64,
},
{
name: "1 byte produces 2 hex chars",
n: 1,
wantLen: 2,
name: "negative n returns error",
n: -1,
wantErr: true,
},
{
name: "large negative n returns error",
n: -100,
wantErr: true,
},
}

for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
result, err := RandomHex(tt.n)
if tt.wantErr {
require.Error(t, err)
assert.Empty(t, result, "result should be empty on error")
return
}
require.NoError(t, err)
assert.Len(t, result, tt.wantLen)
})
}
}

// TestRandomHex_ErrorMessageContainsSize verifies the error for negative n includes the invalid value.
func TestRandomHex_ErrorMessageContainsSize(t *testing.T) {
_, err := RandomHex(-5)
require.Error(t, err)
assert.Contains(t, err.Error(), "-5", "error message should include the invalid size")
}

// TestRandomHex_IsValidHex verifies the output is a valid lowercase hex-encoded string
Copy link

Copilot AI Apr 14, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The comment says the output is a "valid lowercase hex-encoded string", but the test only checks that hex.DecodeString succeeds (which accepts both lower/upper case). Either assert the string is lowercase (e.g., compare to strings.ToLower(result)) or update the comment to just say "hex-encoded" to match what the test verifies.

Suggested change
// TestRandomHex_IsValidHex verifies the output is a valid lowercase hex-encoded string
// TestRandomHex_IsValidHex verifies the output is a valid hex-encoded string

Copilot uses AI. Check for mistakes.
// and that decoding it yields exactly n bytes.
func TestRandomHex_IsValidHex(t *testing.T) {
result, err := RandomHex(16)
require.NoError(t, err)

decoded, decodeErr := hex.DecodeString(result)
require.NoError(t, decodeErr, "result should be valid hex-encoded string")
assert.Len(t, decoded, 16, "decoded bytes should have length equal to input n")
}

func TestRandomHex_Uniqueness(t *testing.T) {
seen := make(map[string]bool)
for i := 0; i < 100; i++ {
Expand Down
Loading